529020
research-article2014
JHLXXX10.1177/0890334414529020Journal of Human LactationLippitt et al
Student Research
An Exploration of Social Desirability Bias in Measurement of Attitudes toward Breastfeeding in Public
Journal of Human Lactation 2014, Vol. 30(3) 358–366 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0890334414529020 jhl.sagepub.com
Margaret Lippitt, MPH1, Amelia Reese Masterson, MPH1, Ana Sierra, MPH1, Amy B. Davis, MPhil, JD1, and Marney A. White, PhD, MS1,2 Abstract Background: Measurement of attitudes toward breastfeeding has been based on self-report, which may be subject to social desirability. Increasing the perceived anonymity of questionnaires may reduce social desirability bias, producing more accurate results. Objective: We compare a standard questionnaire (SQ) with the unmatched count technique (UCT) to understand the effect of increased perceived anonymity on self-reported attitudes toward breastfeeding in public. Methods: Measures of attitudes toward breastfeeding in public were adapted from existing questionnaires, subjected to expert review, and pilot tested. A web-based survey was then constructed to compare the UCT and the SQ technique. Participants were recruited online and randomly assigned to either the SQ or the UCT condition. Results: In the overall sample (N = 1477), the UCT condition had significantly higher endorsement for the statement, “Breastfeeding in some public settings should be against the law” [χ2(1, n = 1455) = 9.58, P = .002]. Women more frequently endorsed that item in the UCT condition (15.6%) than in the SQ condition (7.1%) [χ2(1, n = 1025) = 18.27, P < .001]. In contrast, among men, rates of endorsement did not vary between experimental and control groups for that question. Conclusion: Perceived anonymity may have influenced responses to some questions about attitudes toward breastfeeding in public. The effects of perceived anonymity may operate differently within demographic sectors. The direction of the effects was not always consistent with hypotheses, and future research is needed to fully explore the various dimensions of attitudes toward breastfeeding. The UCT method shows promise for improving the accuracy of reporting attitudes toward breastfeeding. Keywords breastfeeding, breastfeeding attitudes, measurement, public breastfeeding, social desirability, unmatched count technique
Well Established Understanding societal attitudes toward breastfeeding in public is critical for its promotion, since others’ attitudes can influence the likelihood that mothers will breastfeed. Existing research on attitudes toward breastfeeding in public is based on self-reported data that may be subject to social desirability bias.
Newly Expressed This article uses an innovative questionnaire methodology to increase the perceived anonymity of a web-based survey on attitudes toward breastfeeding in public. This increase in perceived anonymity led to significantly higher reporting of some negative attitudes toward breastfeeding in public.
attitudes toward breastfeeding in the United States improves our understanding of the social and psychological factors that contribute to breastfeeding practices. Researchers have found, however, that attitudes toward breastfeeding can be a somewhat sensitive topic and thus difficult to measure accurately due to social desirability bias.1 In this study, we tested the unmatched count technique (UCT) as a possible method for improving the measurement of this potentially sensitive topic. We compared the UCT responses and responses to a standard questionnaire (SQ) to determine whether the UCT has an effect on the responses to these questions. 1
School of Public Health, Yale University, New Haven, CT, USA Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA 2
Date submitted: September 21, 2013; Date accepted: March 2, 2014.
Background Breastfeeding has been shown to have significant clinical and social benefits for infants and mothers.1 Measuring
Corresponding Author: Marney A. White, PhD, MS, Department of Psychiatry, Yale University, 301 Cedar Street, 2nd Floor, New Haven, CT 06520, USA. Email: [email protected]
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Attitudes toward Breastfeeding Breastfeeding offers important health benefits for infants and mothers, including improved nutritional, social, cognitive, and immunological outcomes for the infant, according to Persad and Mensinger.2 The same study found that many Americans also have negative perceptions of breastfeeding in public, with 37% of adults agreeing that “mothers who breastfeed should do so in private places only.” Societal attitudes toward breastfeeding are important indicators of breastfeeding practice.3 Some studies have found that concerns and embarrassment about breastfeeding in public or perceived norms and opinions of the general public can hinder mothers’ efforts to breastfeed.4 A mother’s perception of her partner’s attitude toward breastfeeding can also influence her breastfeeding decisions.5,6
Measuring Attitudes toward Breastfeeding Several tools exist for measuring attitudes toward breastfeeding through direct questionnaire, including the Centers for Disease Control and Prevention’s (CDC) Behavioral Risk Factor Surveillance System Questionnaire, the Infant Nutrition Attitude Questionnaire,7 the Infant Nutrition Knowledge Questionnaire,7 the HealthStyles Questionnaire,8,9 and the WIC Infant Feeding Practices Questionnaire.10 These questionnaires use direct questions to understand attitudes toward breastfeeding, and researchers have acknowledged that social desirability bias could be a key limitation of existing data on breastfeeding attitudes.1 Whereas some researchers have attempted to limit such bias through innovative survey methodologies such as computer-assisted selfinterviewing11 and negative framing of statements,12 we are not aware of previous work on attitudes toward breastfeeding that has used the UCT method to improve the accuracy of responses. The UCT method uses decoy questions and aggregate level rates of endorsement to increase perceived anonymity among participants and thus reduces the influence of social desirability bias in captured data. The UCT method has been successfully applied to reduce social desirability bias in studies of racial attitudes,13 political preferences,14 perceptions of physical attractiveness,15 alcohol and sexual risk behaviors,16 and other topics. Social desirability bias can be present for a variety of reasons, including the sensitive nature of a topic, the mode of data collection, or characteristics of the participant population.17 The UCT method has been found to perform well when compared to other methods such as direct questioning and the randomized response technique in terms of prevalence rate, validity, and perceived anonymity.16-18 By randomly assigning participants to a UCT or a traditional survey, this study examined the influence of perceived anonymity, as afforded by the UCT method, compared to direct questioning for measuring attitudes toward breastfeeding. We also explored
whether participant characteristics such as gender, age, and parent status influence response patterns by experimental condition.
Methods Questionnaire Development Five questions were adapted from the CDC’s Behavioral Risk Factor Surveillance System Questionnaire, the Infant Nutrition Attitude Questionnaire,7 and the HealthStyles Questionnaire.8,9 We specifically focused on attitudes toward breastfeeding in public, a reported key barrier to breastfeeding.19 Decoy questions for the UCT sets were selected and adapted from the Zung Self-Rating Anxiety Scale,20 the Hamilton Youth and Guns Poll,19 and previously used UCT decoy questions.16 A Flesch–Kincaid analysis was also used to assess the reading level of the questionnaire. All questions were adapted to a ninth-grade reading level except 1, which was adapted to a tenth-grade reading level. This question asked whether breastfeeding could be sexually arousing, and we found that any further changes in phrasing would alter the meaning. Expert review. The questionnaire draft on attitudes toward breastfeeding was then sent to 6 experts for review. Five of the experts were professors at Yale School of Public Health, and 1 was a public health professional at another institution with experience in using the UCT method to measure sensitive topics. Review and substantial feedback was provided on several topics including question wording and readability. Expert review led to changes in the questionnaire draft before pilot testing. Prior to administration to the final sample, the questionnaire was pilot tested on a small sample of volunteers (N = 18) to ensure readability. Final measures. Five questions were used to explore 5 dimensions of attitudes toward breastfeeding in public, including laws about breastfeeding in public, appropriate age of children being breastfed, the need for a breastfeeding mother to cover herself, the sexually arousing nature of breastfeeding, and socioeconomic characteristics of breastfeeding mothers (Table 1 contains the final measure). For the SQ condition, questions were presented directly (ie, as standalone items) and required binary responses (agree/disagree). In the UCT condition, questions were embedded in sets of statements, including 1 breastfeeding question of interest and 3 decoy questions. For the sets of questions, participants were asked to choose the total number of questions agreed with, without revealing their opinion on any 1 statement. The SQ condition also received the sets of 3 decoy questions, without the breastfeeding question of interest, to establish a base endorsement rate. Data were also collected on age, gender, race, education, and other key demographic variables.
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Table 1. Final Questionnaire. Standard Questionnaire: Decoy Sets, Used to Establish Baseline Endorsement Rate
Unmatched Count Technique Questionnaire: Decoy Sets, with Breastfeeding Questions of Interest
•• I have a sister. •• I believe that everyone who wants to buy a gun should be required to first pass a safety course. •• In the last 7 days, I have felt more nervous and anxious than usual.
•• I have a sister. •• I believe that everyone who wants to buy a gun should be required to first pass a safety course. •• I think breastfeeding in some public settings should be against the law. •• In the last 7 days, I have felt more nervous and anxious than usual.
•• I have a brother. •• I believe a waiting period should exist between the purchase and delivery of a handgun to keep buyers from acting on impulse. •• In the last 7 days, I have been bothered by headaches.
•• I have a brother. •• I believe a waiting period should exist between the purchase and delivery of a handgun to keep buyers from acting on impulse. •• I think children who are old enough to walk and talk should not be breastfed in public. •• In the last 7 days, I have been bothered by headaches.
•• My birthday is in June. •• I believe handgun buyers should be required to get a gun owner’s license before purchasing a handgun. •• In the last 7 days, I have felt afraid for no reason at all.
•• My birthday is in June. •• I believe handgun buyers should be required to get a gun owner’s license before purchasing a handgun. •• I think that women who breastfeed in public should cover themselves. •• In the last 7 days, I have felt afraid for no reason at all.
•• I have a dog. •• Someone I know has been injured by a firearm, either accidentally or intentionally. •• In the last 7 days, I have had a nightmare.
•• I have a dog. •• Someone I know has been injured by a firearm, either accidentally or intentionally. •• I think that seeing a woman breastfeeding in public can be sexually arousing. •• In the last 7 days, I have had a nightmare.
•• My birthday is on an even day. •• I would support legislation to raise the age at which someone can purchase a handgun from 18 to 21. •• In the last 7 days, I have felt more tired than normal.
•• My birthday is on an even day. •• I would support legislation to raise the age at which someone can purchase a handgun from 18 to 21. •• I think women who breastfeed in public are more likely to be poor. •• In the last 7 days, I have felt more tired than normal.
Recruitment and Participation
Data Analysis
In March and April 2013, we recruited 1477 participants (ages 18 and older) to participate in the self-administered survey using SQ and UCT methods to measure perceptions of breastfeeding in public. Recruitment of participants occurred through various Internet-based and social networking modes. The study was advertised on Craigslist in more than 50 US cities, and other recruitment efforts included direct emails and posts on Facebook, Twitter, Google-chat, and comment threads on several online newspaper and parenting websites. The questionnaire was hosted on a website using Qualtrics software, and participants were randomly assigned to either the SQ or the UCT condition. No personal identifying information was collected. Participants were permitted access to the questionnaire only after they had provided informed consent. Participants first completed a brief demographic survey and then advanced to either the UCT or SQ question sets. No compensation was offered. All measures and methods were approved by Yale University’s Human Subjects Committee.
The endorsement levels of the participants in the SQ condition could be observed directly through the questionnaire responses, and the endorsement levels of the participants in the UCT condition could be calculated based on excess endorsement beyond a base rate. Because the SQ condition received the decoy questions without the breastfeeding question of interest, the level of endorsement of these decoy questions by the SQ condition was used as the baseline level of endorsement. The UCT condition received the decoy questions and the breastfeeding question of interest in 1 set, so any excess endorsement above the SQ condition baseline was considered to be attributable to the addition of the breastfeeding question of interest. Calculating the difference between the mean response rate on the decoy set in the SQ condition and the mean response rate on the corresponding set of UCT questions yielded the response rate for each critical item. Heterogeneity in the endorsement patterns of the SQ and UCT participants was tested using the chi-square (χ2) test for
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Lippitt et al Table 2. Percentage of People Who Agreed with the Questions of Interest.a
Survey Question 1. I think breastfeeding in some public settings should be against the law. 2. I think children who are old enough to walk and talk should not be breastfed in public. 3. I think that women who breastfeed in public should cover themselves. 4. I think that seeing a woman breastfeeding in public can be sexually arousing. 5. I think women who breastfeed in public are more likely to be poor.
Standard Questionnaire (N = 736), No. (%)
Unmatched Count Technique (N = 741), No. (%)b
χ2 Value
Factorc
P Valued
68 (9.4)
107 (14.7)
9.6
1.6
.002
385 (53.3)
407 (55.7)
0.9
1.0
.353
491 (67.8)
460 (63.2)
3.5
0.9
.063
96 (13.3)
84 (11.5)
1.0
0.9
.324
46 (6.4)
42 (5.8)
0.2
0.9
.626
a
Valid percentages are used in this table, so the denominator for each item may not reflect the total sample randomized to this condition. Percentage endorsement for the standard questionnaire (SQ) condition was reported directly. Percentage endorsement for the unmatched count technique (UCT) condition was calculated based on the excess endorsement above the SQ condition baseline. c The “factor” score is derived by dividing the UCT percentage by the SQ percentage. The “1.6” for Question 1 indicates that participants in the UCT condition were 1.6 times as likely to admit that they think breastfeeding in some public places should be against the law, compared to those in the SQ condition. d P value is for χ2 test for independence. b
independence. Statistical analyses were carried out using IBM SPSS Statistics 21.0 and Microsoft Excel.
Results Characteristics of the Sample The median age of participants was 28.0 years (interquartile range, 20-36 years). The majority of the sample was white (77.5%) and female (70.7%) and had at least a college degree (78.7%). Parents made up 30.3% of the sample. There were no significant differences between the SQ and the UCT groups in terms of demography (ie, age, gender, race, education).
Comparison of SQ and UCT Conditions The endorsement rates for individual questionnaire items are shown by experimental condition in Table 2. Participants assigned to the UCT condition were significantly more likely to endorse Question 1 (“I think breastfeeding in some public settings should be against the law”) as compared to when the question was presented in isolation. To further compare endorsement rates for each method, we conducted stratified analyses by gender, race, and whether or not the participant was a parent. The stratified results for gender are shown in Table 3. Question 1 (“I think breastfeeding in some public settings should be against the law”) was endorsed more frequently among women in the UCT condition (15.6%) than in the SQ condition (7.1%). In contrast, among men, rates of endorsement did not vary between experimental and control groups for that question. Question 5 (“I think women who breastfeed in public are more likely
to be poor”), however, yielded different rates of endorsement by gender. Among men, lower rates of endorsement were reported on Question 5 in the UCT condition. Women, on the other hand, reported higher rates of endorsement for Question 5 in the UCT condition. Because of the difference in direction of effect across gender groups, no difference was observed between the UCT and SQ groups in the overall analysis (ie, prior to stratification by gender). As shown in Table 4, significant differences were observed in the patterns of endorsement across parents and nonparents. For many items, nonparents were more likely to endorse a negative attitude toward breastfeeding than were parents, and this relationship appears for both the SQ and the UCT conditions. At the same time, the effect of the UCT method was different for parents and nonparents on some items. For example, parents were significantly more likely to endorse Question 5 (“I think women who breastfeed in public are more likely to be poor”) if they were in the UCT condition compared to the SQ condition, and nonparents were significantly less likely to endorse Question 5 if they were in the UCT condition compared to the SQ condition. This relationship could be related to a difference in age between parents and nonparents, whose average ages were 45.5 years and 33.4 years, respectively. Because of a lack of individuallevel data in this type of analysis, it is not possible to control for variables such as age. Stratified analysis by race is shown in Table 5. As in the case of the gender stratification, multiple differences were observed in the levels of endorsement between the 2 experimental conditions. Contrary to our original hypothesis, the stratified analysis shows that in a few cases, participants in the UCT condition were less likely to endorse the items than participants in the SQ condition. For example, whites in the
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Table 3. Percentage of People Who Agreed with the Questions of Interest, by Gender.a Men
Survey Question 1. I think breastfeeding in some public settings should be against the law. 2. I think children who are old enough to walk and talk should not be breastfed in public. 3. I think that women who breastfeed in public should cover themselves. 4. I think that seeing a woman breastfeeding in public can be sexually arousing. 5. I think women who breastfeed in public are more likely to be poor.
Women
Unmatched Unmatched Standard Standard Count Count Questionnaire Technique Questionnaire Technique χ2 P χ2 P (N = 507), (N = 216), (N = 519), (N = 207), b c d b Value Factor Value Value Factorc Valued No. (%) No. (%) No. (%) No. (%) 30 (14.0)
27 (13.3)
0.1
0.9
.785
36 (7.1)
81 (15.6)
18.3
2.2
< .001
131 (61.2)
115 (55.7)
1.4
0.9
.239
252 (50.1)
287 (55.4)
2.9
1.1
.090
151 (70.6)
106 (51.8)
15.7
0.7
< .001
337 (66.7)
347 (67.0)
0.0
1.0
.929
38 (17.8)
56 (27.0)
5.3
1.5
.022
56 (11.1)
29 (5.6)
9.9
0.5
.002
21 (9.8)
0 (0.0)
20.3
0.0
< .001
24 (4.8)
47 (9.1)
7.3
1.9
.007
a
Valid percentages are used in this table, so the denominator for each item may not reflect the total sample randomized to this condition. Percentage endorsement for the standard questionnaire (SQ) condition was reported directly. Percentage endorsement for the unmatched count technique (UCT) condition was calculated based on the excess endorsement above the SQ condition baseline. c The “factor” score is derived by dividing the UCT percentage by the SQ percentage. The “2.2” for Question 1 indicates that women in the UCT condition were 2.2 times as likely to admit that they think breastfeeding in some public places should be against the law, compared to women in the SQ condition. d P value is for χ2 test for independence. b
UCT condition were less likely to endorse Question 5 (“I think women who breastfeed in public are more likely to be poor”) than their counterparts in the SQ condition.
Discussion Our study results indicate that, for some questions investigating attitudes toward public breastfeeding, participants are more likely to indicate negative attitudes when in the UCT condition compared to direct questioning. This was consistent with our hypothesis that social desirability bias may be guiding responses to sensitive questions about breastfeeding in public. The goal of the UCT method is to increase perceived anonymity among participants responding to sensitive questions with the aim of reducing social desirability bias. However, the predicted effect was not found across all questions and differed by gender, race, and parental status.
In the overall sample, Question 1 (“I think breastfeeding in some public settings should be against the law”) received significantly higher endorsement by those in the UCT condition compared to the SQ condition, indicating that this question is subject to social desirability bias. Upon stratification by gender, this result held only for the female group, with women in the UCT condition being more than twice as likely to endorse the belief as women in the SQ condition. This suggests greater social pressure on women to oppose legal restrictions on breastfeeding in public places. When stratified by race, this result held only for whites, possibly indicating a similar pressure on whites. Although Question 2 (“I think children who are old enough to walk and talk should not be breastfed in public”) did not differ by method in the overall sample, when stratified by parental status, higher endorsement was found among nonparents in the UCT condition compared to the SQ condition. This difference may reflect an increased sensitivity
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Lippitt et al Table 4. Percentage of People Who Agreed with the Questions of Interest, by Parent Status.a Parent
Survey Question 1. I think breastfeeding in some public settings should be against the law. 2. I think children who are old enough to walk and talk should not be breastfed in public. 3. I think that women who breastfeed in public should cover themselves. 4. I think that seeing a woman breastfeeding in public can be sexually arousing. 5. I think women who breastfeed in public are more likely to be poor.
Not Parent
Unmatched Unmatched Standard Standard Count Count Questionnaire Technique Questionnaire Technique χ2 P χ2 P (N = 482), (N = 212), (N = 487), (N = 208), b c d b Value Factor Value Value Factorc Valued No. (%) No. (%) No. (%) No. (%) 19 (9.0)
12 (5.6)
1.6
0.6
.206
47 (9.8)
91 (18.6)
15.9
1.9
< .001
100 (47.6)
91 (44.0)
0.6
0.9
.453
247 (57.1)
297 (60.9)
1.5
1.1
.045
155 (73.1)
130 (62.6)
5.4
0.9
.020
316 (65.8)
310 (63.9)
0.4
1.0
.533
18 (8.6)
19 (9.1)
0.1
1.1
.803
75 (15.6)
70 (14.3)
0.3
0.9
.605
8 (3.8)
36 (17.4)
20.2
4.6
< .001
38 (7.9)
9 (1.9)
19.2
0.2
< .001
a
Valid percentages are used in this table, so the denominator for each item may not reflect the total sample randomized to this condition. Percentage endorsement for the standard questionnaire (SQ) condition was reported directly. Percentage endorsement for the unmatched count technique (UCT) condition was calculated based on the excess endorsement above the SQ condition baseline. c The “factor” score is derived by dividing the UCT percentage by the SQ percentage. The “1.9” for Question 1 indicates that nonparents in the UCT condition were 1.9 times as likely to admit that they think breastfeeding in some public places should be against the law, compared to nonparents in the SQ condition. d P value is for χ2 test for independence. b
related to breastfeeding older children in public among those who lack personal experience raising a child. It is interesting that men were significantly more likely to endorse Question 4 (“I think that seeing a woman breastfeeding in public can be sexually arousing”) in the UCT condition, but women were significantly more likely to endorse this question in the SQ condition. This finding indicates an interaction with gender and may show that men feel that they cannot admit overtly that they find public breastfeeding sexually arousing, whereas women are actually more likely to admit this overtly than anonymously. This finding in the female population could be due to the lack of clarity of the question (ie, some may have assumed that the question referred to men’s perception of breastfeeding as sexually
arousing rather than personal perception). Past research on attitudes toward breastfeeding by gender shows mixed results, indicating that further research is needed on this relationship.21 The UCT method shows potential for clarifying the differences in attitudes toward breastfeeding by gender by reducing social desirability bias. When we stratified by gender, race, and parental status, we found significantly different endorsement rates between UCT and SQ. Women, non-whites, and parents were much more likely to endorse Question 5 (“I think women who breastfeed in public are more likely to be poor”) in the UCT group than in the SQ group, suggesting that these groups feel greater pressure to conceal their perspective that breastfeeding in public is related to poverty compared to their
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Table 5. Percentage of People Who Agreed with the Questions of Interest, by Race.a White
Survey Question 1. I think breastfeeding in some public settings should be against the law. 2. I think children who are old enough to walk and talk should not be breastfed in public. 3. I think that women who breastfeed in public should cover themselves. 4. I think that seeing a woman breastfeeding in public can be sexually arousing. 5. I think women who breastfeed in public are more likely to be poor.
Non-White
Unmatched Unmatched Standard Standard Count Count Questionnaire Technique Questionnaire Technique χ2 P χ2 P (N = 156), (N = 566), (N = 169), (N = 554), b c d b Value Factor Value Value Factorc Valued No. (%) No. (%) No. (%) No. (%) 50 (8.8)
88 (15.8)
12.8
1.8
< .001
16 (10.3)
23 (13.8)
0.9
1.3
.343
300 (53.3)
298 (54.0)
0.0
1.0
.840
82 (52.9)
105 (61.9)
2.8
1.2
.093
380 (67.1)
342 (61.9)
3.3
0.9
.070
107 (69.5)
111 (66.3)
0.4
1.0
.513
65 (11.5)
56 (10.2)
0.5
0.9
.472
31 (19.9)
23 (13.7)
2.3
0.7
.130
29 (5.1)
0 (0.0)
28.2
0.0
< .001
17 (11.0)
40 (23.5)
9.0
2.1
.003
a
Valid percentages are used in this table, so the denominator for each item may not reflect the total sample randomized to this condition. Percentage endorsement for the standard questionnaire (SQ) condition was reported directly. Percentage endorsement for the unmatched count technique (UCT) condition was calculated based on the excess endorsement above the SQ condition baseline. c The “factor” score is derived by dividing the UCT percentage by the SQ percentage. The “1.8” for Question 1 indicates that whites in the UCT condition were 1.8 times as likely to admit that they think breastfeeding in some public places should be against the law, compared to whites in the SQ condition. d P value is for χ2 test for independence. b
counterparts. Although stratifying our results by gender, race, and parental status revealed significant differences in endorsement rates of certain questions between UCT and SQ, these differences were not always in the expected direction. Men in the SQ group were more likely to respond positively to Question 5 and Question 3 (“I think that women who breastfeed in public should cover themselves”) than men in the UCT group. This significant decrease in endorsement in the UCT group may indicate that this was not a sensitive question for men, such that they actually preferred to respond overtly rather than anonymously. A similar counterintuitive result was found among parents, who showed higher rates of endorsement of the “cover
themselves” question in the SQ condition as compared to the UCT condition. Unexpected results such as these may also indicate a context effect, that is, a tendency to endorse research questions more or less based on their positioning within the context of the decoy questions in the UCT group. However, we cannot parse out the influence of context within this dataset. This potential limitation is discussed further below.
Strengths and Limitations By testing the UCT method to assess attitudes toward breastfeeding practices, this study expands on the tools available
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Lippitt et al for research in this area and enables researchers to obtain more accurate responses to sensitive questions regarding negative perceptions of breastfeeding in public. Considering the many benefits of breastfeeding for both mother and infant,2,22 and the lack of knowledge and negative attitudes surrounding breastfeeding in the United States,23 the measurement advantages associated with using the UCT methodology are particularly salient. Other data on attitudes toward breastfeeding have been collected through several methods, including mail,9 telephone,7 and in-person7 administration. Our findings suggest that the UCT method—as administered via web-based survey—may improve reporting of sensitive issues, such as attitudes toward breastfeeding in public. We would expect the UCT method to be even more effective in increasing accuracy of reporting sensitive topics using more direct survey modes (eg, in-person). These strengths notwithstanding, our study has several limitations. A potential limitation of the UCT is the possibility that the decoy statements affect the participant’s attitude toward the question of interest. In the case of this study, we included decoy questions in each set relating to perspectives on gun control. It is possible that participants who were strongly opposed to gun control measures may have reacted by underendorsing all UCT questions in an effort to clearly communicate their lack of endorsement for the statements related to gun control. This may have resulted in a context effect in the UCT group and systematic underendorsement of some breastfeeding questions in this group. However, given that we observed a distribution of endorsement rates of the decoy questions in both conditions, this possibility is minimized. In addition, this study was designed to assess the use of the UCT method for measuring responses to sensitive questions on attitudes toward breastfeeding in public, rather than to assess attitudes toward breastfeeding more generally. Therefore, we caution against broad application of our findings regarding attitudes toward breastfeeding, since this construct was not evaluated by the questionnaire. As previous research has shown, the UCT method allows for only dichotomous responses, thus limiting our ability to compare these results with existing surveys that use a Likert scale style with multiple response options.24 Finally, we were not able to control for individual-level variables such as age because the UCT endorsement rates are estimated for the entire participant group, and not at the individual level. It is important to note that we were not able to collect data on the actual breastfeeding experiences or practices of our participants, which would be useful information for assessing attitudes toward breastfeeding. Future studies should collect information on breastfeeding experiences and analyze the relationship between personal experience and sensitivity around attitudes toward breastfeeding. Future research should also explore gender to determine whether attitudes of male and female parents differ from those of nonparents.
Implications Despite limitations, this research is important because it tests an innovative methodology for improving measurement of attitudes toward breastfeeding. A better understanding of the societal perspectives on breastfeeding could contribute to more nuanced public health policies, programs, and clinical recommendations for improving breastfeeding practices. To our knowledge, this is the first study to test the UCT method for measuring attitudes toward breastfeeding. The UCT method shows promise for improving estimates of negative attitudes toward breastfeeding, since the current research in this area is likely distorted by social desirability bias.2 In particular, this method may be useful for assessing male partner attitudes toward breastfeeding, which is an important predictor of a mother’s decision to breastfeed.6
Conclusion This study used an innovative questionnaire methodology, the UCT, to increase the perceived anonymity of a webbased survey on attitudes toward breastfeeding in public. The increase in perceived anonymity afforded by the UCT led to significantly higher endorsement of some negative attitudes toward breastfeeding in public, which raises questions about the quality of existing data on this topic. The effects of perceived anonymity may operate differently within different demographic sectors. The direction of the effects found here was not always consistent with hypotheses, and future research is needed to fully explore the various dimensions of attitudes toward breastfeeding. The UCT method shows promise for improving the accuracy of reporting of attitudes toward breastfeeding in public. Acknowledgments For their support in the development of the survey tool, we would like to thank Dr Debbie Humphries, Dr Rafael Perez-Escamilla, Dr Mary Alice Lee, Dr Mayur Desai, and Gogi Grewal.
Declaration of Conflicting Interests The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The authors received no financial support for the research, authorship, and/or publication of this article.
References 1. Taylor JS, Risica PM, Geller L, Kirtania U, Cabral HJ. Duration of breastfeeding among first-time mothers in the United States: results of a national survey. Acta Paediatr. 2006;95(8):980-984. 2. Persad MD, Mensinger JL. Maternal breastfeeding attitudes: association with breastfeeding intent and socio-demographics among urban primiparas. J Community Health. 2008;33(2):53-60.
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3. Stanton RW. A road map for change: ensuring that women have breastfeeding support. J Perinat Educ. 2011;20(3):130-133. 4. Furman LM, Banks EC, North AB. Breastfeeding among highrisk inner-city African-American mothers: a risky choice? Breastfeed Med. 2013;8(1):58-67. 5. Arora S, McJunkin C, Wehrer J, Kuhn P. Major factors influencing breastfeeding rates: mother’s perception of father’s attitude and milk supply. Pediatrics. 2000;106(5):e67. 6. Johnson AM, Correll A, Greene JF, Hein D, McLaughlin T. Barriers to breastfeeding in a resident clinic. Breastfeeding Med. 2013;8(3):273-276. 7. Pollock CA, Bustamante-Forest R, Giarratano G. Men of diverse cultures: knowledge and attitudes about breastfeeding. J Obstet Gynecol Neonatal Nurs. 2002;31(6):673-679. 8. Li R, Rock VJ, Grummer-Strawn L. Changes in public attitudes toward breastfeeding in the United States, 1999-2003. J Am Diet Assoc. 2007;107(1):122-127. 9. HealthStyles survey—breastfeeding practices: 2010. Centers for Disease Control and Prevention website. http://www.cdc. gov/breastfeeding/data/healthstyles_survey/survey_2010.htm. Updated December 2, 2013. Accessed February 26, 2014. 10. Fein SB, Labiner-Wolfe J, Shealy KR, Li R, Chen J, GrummerStrawn LM. Infant Feeding Practices Study II: study methods. Pediatrics. 2008;122(suppl 2):S28-S35. 11. Waruru AK, Nduati R, Tylleskär T. Audio computer-assisted self-interviewing (ACASI) may avert socially desirable responses about infant feeding in the context of HIV. BMC Med Inform Decis Mak. 2005;5(1):24. 12. Kloeblen-Tarver AS, Thompson NJ, Miner KR. Intent to breast-feed: the impact of attitudes, norms, parity, and experience. Am J Health Behav. 2002;26(3):182-187. 13. Kuklinski JH, Sniderman PM, Knight K, et al. Racial prejudice and attitudes toward affirmative action. Am J Pol Sci. 1997;41(2):402-419.
14. Streb MJ, Burrell B, Frederick B, Genovese MA. Social desirability effects and support for a female American president. Public Opin Q. 2008;72(1):76-89. 15. Conley D, McCabe BJ. Body mass index and physical attractiveness: evidence from a combination image-alteration/list experiment. Sociol Methods Res. 2011;40(1):6-31. 16. LaBrie JW, Earleywine M. Sexual risk behaviors and alcohol: higher base rates revealed using the unmatched-count technique. J Sex Res. 2000;37(4):321-326. 17. Coutts E, Jann B. Sensitive questions in online surveys: experimental results for the randomized response technique (RRT) and the unmatched count technique (UCT). Sociol Methods Res. 2011;40(1):169-193. 18. Dalton DR, Wimbush JC, Daily CM. Using the unmatched count technique (UCT) to estimate base rates for sensitive behavior. Pers Psychol. 1994;47(4):817-829. 19. Vittes KA, Sorenson SB, Gilbert D. High school stu dents’ attitudes about firearms policies. J Adolesc Health. 2003;33(6):471-478. 20. Zung W, Cavenar J. Assessment scales and techniques. In: Kutash IL, ed. Handbook of Stress and Anxiety. San Francisco, CA: Jossey-Bass; 1980:348-363. 21. Acker M. Breast is best . . . but not everywhere: ambivalent sexism and attitudes toward private and public breastfeeding. Sex Roles. 2009;61(7-8):476-490. 22. James D, Dobson B. American Dietetic Association. Position of the American Dietetic Association: promoting and supporting breastfeeding. J Am Diet Assoc. 2005;105(5): 810-818. 23. Li R, Fridinger F, Grummer-Strawn L. Public perceptions on breastfeeding constraints. J Hum Lact. 2002;18(3):227-235. 24. Lavender JM, Anderson DA. Effect of perceived anonymity in assessments of eating disordered behaviors and attitudes. Int J Eat Disord. 2009;42(6):546-551.
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research-article2014
JHLXXX10.1177/0890334414529020Journal of Human LactationLippitt et al
Student Research
An Exploration of Social Desirability Bias in Measurement of Attitudes toward Breastfeeding in Public
Journal of Human Lactation 2014, Vol. 30(3) 358–366 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0890334414529020 jhl.sagepub.com
Margaret Lippitt, MPH1, Amelia Reese Masterson, MPH1, Ana Sierra, MPH1, Amy B. Davis, MPhil, JD1, and Marney A. White, PhD, MS1,2 Abstract Background: Measurement of attitudes toward breastfeeding has been based on self-report, which may be subject to social desirability. Increasing the perceived anonymity of questionnaires may reduce social desirability bias, producing more accurate results. Objective: We compare a standard questionnaire (SQ) with the unmatched count technique (UCT) to understand the effect of increased perceived anonymity on self-reported attitudes toward breastfeeding in public. Methods: Measures of attitudes toward breastfeeding in public were adapted from existing questionnaires, subjected to expert review, and pilot tested. A web-based survey was then constructed to compare the UCT and the SQ technique. Participants were recruited online and randomly assigned to either the SQ or the UCT condition. Results: In the overall sample (N = 1477), the UCT condition had significantly higher endorsement for the statement, “Breastfeeding in some public settings should be against the law” [χ2(1, n = 1455) = 9.58, P = .002]. Women more frequently endorsed that item in the UCT condition (15.6%) than in the SQ condition (7.1%) [χ2(1, n = 1025) = 18.27, P < .001]. In contrast, among men, rates of endorsement did not vary between experimental and control groups for that question. Conclusion: Perceived anonymity may have influenced responses to some questions about attitudes toward breastfeeding in public. The effects of perceived anonymity may operate differently within demographic sectors. The direction of the effects was not always consistent with hypotheses, and future research is needed to fully explore the various dimensions of attitudes toward breastfeeding. The UCT method shows promise for improving the accuracy of reporting attitudes toward breastfeeding. Keywords breastfeeding, breastfeeding attitudes, measurement, public breastfeeding, social desirability, unmatched count technique
Well Established Understanding societal attitudes toward breastfeeding in public is critical for its promotion, since others’ attitudes can influence the likelihood that mothers will breastfeed. Existing research on attitudes toward breastfeeding in public is based on self-reported data that may be subject to social desirability bias.
Newly Expressed This article uses an innovative questionnaire methodology to increase the perceived anonymity of a web-based survey on attitudes toward breastfeeding in public. This increase in perceived anonymity led to significantly higher reporting of some negative attitudes toward breastfeeding in public.
attitudes toward breastfeeding in the United States improves our understanding of the social and psychological factors that contribute to breastfeeding practices. Researchers have found, however, that attitudes toward breastfeeding can be a somewhat sensitive topic and thus difficult to measure accurately due to social desirability bias.1 In this study, we tested the unmatched count technique (UCT) as a possible method for improving the measurement of this potentially sensitive topic. We compared the UCT responses and responses to a standard questionnaire (SQ) to determine whether the UCT has an effect on the responses to these questions. 1
School of Public Health, Yale University, New Haven, CT, USA Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA 2
Date submitted: September 21, 2013; Date accepted: March 2, 2014.
Background Breastfeeding has been shown to have significant clinical and social benefits for infants and mothers.1 Measuring
Corresponding Author: Marney A. White, PhD, MS, Department of Psychiatry, Yale University, 301 Cedar Street, 2nd Floor, New Haven, CT 06520, USA. Email: [email protected]
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Attitudes toward Breastfeeding Breastfeeding offers important health benefits for infants and mothers, including improved nutritional, social, cognitive, and immunological outcomes for the infant, according to Persad and Mensinger.2 The same study found that many Americans also have negative perceptions of breastfeeding in public, with 37% of adults agreeing that “mothers who breastfeed should do so in private places only.” Societal attitudes toward breastfeeding are important indicators of breastfeeding practice.3 Some studies have found that concerns and embarrassment about breastfeeding in public or perceived norms and opinions of the general public can hinder mothers’ efforts to breastfeed.4 A mother’s perception of her partner’s attitude toward breastfeeding can also influence her breastfeeding decisions.5,6
Measuring Attitudes toward Breastfeeding Several tools exist for measuring attitudes toward breastfeeding through direct questionnaire, including the Centers for Disease Control and Prevention’s (CDC) Behavioral Risk Factor Surveillance System Questionnaire, the Infant Nutrition Attitude Questionnaire,7 the Infant Nutrition Knowledge Questionnaire,7 the HealthStyles Questionnaire,8,9 and the WIC Infant Feeding Practices Questionnaire.10 These questionnaires use direct questions to understand attitudes toward breastfeeding, and researchers have acknowledged that social desirability bias could be a key limitation of existing data on breastfeeding attitudes.1 Whereas some researchers have attempted to limit such bias through innovative survey methodologies such as computer-assisted selfinterviewing11 and negative framing of statements,12 we are not aware of previous work on attitudes toward breastfeeding that has used the UCT method to improve the accuracy of responses. The UCT method uses decoy questions and aggregate level rates of endorsement to increase perceived anonymity among participants and thus reduces the influence of social desirability bias in captured data. The UCT method has been successfully applied to reduce social desirability bias in studies of racial attitudes,13 political preferences,14 perceptions of physical attractiveness,15 alcohol and sexual risk behaviors,16 and other topics. Social desirability bias can be present for a variety of reasons, including the sensitive nature of a topic, the mode of data collection, or characteristics of the participant population.17 The UCT method has been found to perform well when compared to other methods such as direct questioning and the randomized response technique in terms of prevalence rate, validity, and perceived anonymity.16-18 By randomly assigning participants to a UCT or a traditional survey, this study examined the influence of perceived anonymity, as afforded by the UCT method, compared to direct questioning for measuring attitudes toward breastfeeding. We also explored
whether participant characteristics such as gender, age, and parent status influence response patterns by experimental condition.
Methods Questionnaire Development Five questions were adapted from the CDC’s Behavioral Risk Factor Surveillance System Questionnaire, the Infant Nutrition Attitude Questionnaire,7 and the HealthStyles Questionnaire.8,9 We specifically focused on attitudes toward breastfeeding in public, a reported key barrier to breastfeeding.19 Decoy questions for the UCT sets were selected and adapted from the Zung Self-Rating Anxiety Scale,20 the Hamilton Youth and Guns Poll,19 and previously used UCT decoy questions.16 A Flesch–Kincaid analysis was also used to assess the reading level of the questionnaire. All questions were adapted to a ninth-grade reading level except 1, which was adapted to a tenth-grade reading level. This question asked whether breastfeeding could be sexually arousing, and we found that any further changes in phrasing would alter the meaning. Expert review. The questionnaire draft on attitudes toward breastfeeding was then sent to 6 experts for review. Five of the experts were professors at Yale School of Public Health, and 1 was a public health professional at another institution with experience in using the UCT method to measure sensitive topics. Review and substantial feedback was provided on several topics including question wording and readability. Expert review led to changes in the questionnaire draft before pilot testing. Prior to administration to the final sample, the questionnaire was pilot tested on a small sample of volunteers (N = 18) to ensure readability. Final measures. Five questions were used to explore 5 dimensions of attitudes toward breastfeeding in public, including laws about breastfeeding in public, appropriate age of children being breastfed, the need for a breastfeeding mother to cover herself, the sexually arousing nature of breastfeeding, and socioeconomic characteristics of breastfeeding mothers (Table 1 contains the final measure). For the SQ condition, questions were presented directly (ie, as standalone items) and required binary responses (agree/disagree). In the UCT condition, questions were embedded in sets of statements, including 1 breastfeeding question of interest and 3 decoy questions. For the sets of questions, participants were asked to choose the total number of questions agreed with, without revealing their opinion on any 1 statement. The SQ condition also received the sets of 3 decoy questions, without the breastfeeding question of interest, to establish a base endorsement rate. Data were also collected on age, gender, race, education, and other key demographic variables.
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Table 1. Final Questionnaire. Standard Questionnaire: Decoy Sets, Used to Establish Baseline Endorsement Rate
Unmatched Count Technique Questionnaire: Decoy Sets, with Breastfeeding Questions of Interest
•• I have a sister. •• I believe that everyone who wants to buy a gun should be required to first pass a safety course. •• In the last 7 days, I have felt more nervous and anxious than usual.
•• I have a sister. •• I believe that everyone who wants to buy a gun should be required to first pass a safety course. •• I think breastfeeding in some public settings should be against the law. •• In the last 7 days, I have felt more nervous and anxious than usual.
•• I have a brother. •• I believe a waiting period should exist between the purchase and delivery of a handgun to keep buyers from acting on impulse. •• In the last 7 days, I have been bothered by headaches.
•• I have a brother. •• I believe a waiting period should exist between the purchase and delivery of a handgun to keep buyers from acting on impulse. •• I think children who are old enough to walk and talk should not be breastfed in public. •• In the last 7 days, I have been bothered by headaches.
•• My birthday is in June. •• I believe handgun buyers should be required to get a gun owner’s license before purchasing a handgun. •• In the last 7 days, I have felt afraid for no reason at all.
•• My birthday is in June. •• I believe handgun buyers should be required to get a gun owner’s license before purchasing a handgun. •• I think that women who breastfeed in public should cover themselves. •• In the last 7 days, I have felt afraid for no reason at all.
•• I have a dog. •• Someone I know has been injured by a firearm, either accidentally or intentionally. •• In the last 7 days, I have had a nightmare.
•• I have a dog. •• Someone I know has been injured by a firearm, either accidentally or intentionally. •• I think that seeing a woman breastfeeding in public can be sexually arousing. •• In the last 7 days, I have had a nightmare.
•• My birthday is on an even day. •• I would support legislation to raise the age at which someone can purchase a handgun from 18 to 21. •• In the last 7 days, I have felt more tired than normal.
•• My birthday is on an even day. •• I would support legislation to raise the age at which someone can purchase a handgun from 18 to 21. •• I think women who breastfeed in public are more likely to be poor. •• In the last 7 days, I have felt more tired than normal.
Recruitment and Participation
Data Analysis
In March and April 2013, we recruited 1477 participants (ages 18 and older) to participate in the self-administered survey using SQ and UCT methods to measure perceptions of breastfeeding in public. Recruitment of participants occurred through various Internet-based and social networking modes. The study was advertised on Craigslist in more than 50 US cities, and other recruitment efforts included direct emails and posts on Facebook, Twitter, Google-chat, and comment threads on several online newspaper and parenting websites. The questionnaire was hosted on a website using Qualtrics software, and participants were randomly assigned to either the SQ or the UCT condition. No personal identifying information was collected. Participants were permitted access to the questionnaire only after they had provided informed consent. Participants first completed a brief demographic survey and then advanced to either the UCT or SQ question sets. No compensation was offered. All measures and methods were approved by Yale University’s Human Subjects Committee.
The endorsement levels of the participants in the SQ condition could be observed directly through the questionnaire responses, and the endorsement levels of the participants in the UCT condition could be calculated based on excess endorsement beyond a base rate. Because the SQ condition received the decoy questions without the breastfeeding question of interest, the level of endorsement of these decoy questions by the SQ condition was used as the baseline level of endorsement. The UCT condition received the decoy questions and the breastfeeding question of interest in 1 set, so any excess endorsement above the SQ condition baseline was considered to be attributable to the addition of the breastfeeding question of interest. Calculating the difference between the mean response rate on the decoy set in the SQ condition and the mean response rate on the corresponding set of UCT questions yielded the response rate for each critical item. Heterogeneity in the endorsement patterns of the SQ and UCT participants was tested using the chi-square (χ2) test for
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Lippitt et al Table 2. Percentage of People Who Agreed with the Questions of Interest.a
Survey Question 1. I think breastfeeding in some public settings should be against the law. 2. I think children who are old enough to walk and talk should not be breastfed in public. 3. I think that women who breastfeed in public should cover themselves. 4. I think that seeing a woman breastfeeding in public can be sexually arousing. 5. I think women who breastfeed in public are more likely to be poor.
Standard Questionnaire (N = 736), No. (%)
Unmatched Count Technique (N = 741), No. (%)b
χ2 Value
Factorc
P Valued
68 (9.4)
107 (14.7)
9.6
1.6
.002
385 (53.3)
407 (55.7)
0.9
1.0
.353
491 (67.8)
460 (63.2)
3.5
0.9
.063
96 (13.3)
84 (11.5)
1.0
0.9
.324
46 (6.4)
42 (5.8)
0.2
0.9
.626
a
Valid percentages are used in this table, so the denominator for each item may not reflect the total sample randomized to this condition. Percentage endorsement for the standard questionnaire (SQ) condition was reported directly. Percentage endorsement for the unmatched count technique (UCT) condition was calculated based on the excess endorsement above the SQ condition baseline. c The “factor” score is derived by dividing the UCT percentage by the SQ percentage. The “1.6” for Question 1 indicates that participants in the UCT condition were 1.6 times as likely to admit that they think breastfeeding in some public places should be against the law, compared to those in the SQ condition. d P value is for χ2 test for independence. b
independence. Statistical analyses were carried out using IBM SPSS Statistics 21.0 and Microsoft Excel.
Results Characteristics of the Sample The median age of participants was 28.0 years (interquartile range, 20-36 years). The majority of the sample was white (77.5%) and female (70.7%) and had at least a college degree (78.7%). Parents made up 30.3% of the sample. There were no significant differences between the SQ and the UCT groups in terms of demography (ie, age, gender, race, education).
Comparison of SQ and UCT Conditions The endorsement rates for individual questionnaire items are shown by experimental condition in Table 2. Participants assigned to the UCT condition were significantly more likely to endorse Question 1 (“I think breastfeeding in some public settings should be against the law”) as compared to when the question was presented in isolation. To further compare endorsement rates for each method, we conducted stratified analyses by gender, race, and whether or not the participant was a parent. The stratified results for gender are shown in Table 3. Question 1 (“I think breastfeeding in some public settings should be against the law”) was endorsed more frequently among women in the UCT condition (15.6%) than in the SQ condition (7.1%). In contrast, among men, rates of endorsement did not vary between experimental and control groups for that question. Question 5 (“I think women who breastfeed in public are more likely
to be poor”), however, yielded different rates of endorsement by gender. Among men, lower rates of endorsement were reported on Question 5 in the UCT condition. Women, on the other hand, reported higher rates of endorsement for Question 5 in the UCT condition. Because of the difference in direction of effect across gender groups, no difference was observed between the UCT and SQ groups in the overall analysis (ie, prior to stratification by gender). As shown in Table 4, significant differences were observed in the patterns of endorsement across parents and nonparents. For many items, nonparents were more likely to endorse a negative attitude toward breastfeeding than were parents, and this relationship appears for both the SQ and the UCT conditions. At the same time, the effect of the UCT method was different for parents and nonparents on some items. For example, parents were significantly more likely to endorse Question 5 (“I think women who breastfeed in public are more likely to be poor”) if they were in the UCT condition compared to the SQ condition, and nonparents were significantly less likely to endorse Question 5 if they were in the UCT condition compared to the SQ condition. This relationship could be related to a difference in age between parents and nonparents, whose average ages were 45.5 years and 33.4 years, respectively. Because of a lack of individuallevel data in this type of analysis, it is not possible to control for variables such as age. Stratified analysis by race is shown in Table 5. As in the case of the gender stratification, multiple differences were observed in the levels of endorsement between the 2 experimental conditions. Contrary to our original hypothesis, the stratified analysis shows that in a few cases, participants in the UCT condition were less likely to endorse the items than participants in the SQ condition. For example, whites in the
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Table 3. Percentage of People Who Agreed with the Questions of Interest, by Gender.a Men
Survey Question 1. I think breastfeeding in some public settings should be against the law. 2. I think children who are old enough to walk and talk should not be breastfed in public. 3. I think that women who breastfeed in public should cover themselves. 4. I think that seeing a woman breastfeeding in public can be sexually arousing. 5. I think women who breastfeed in public are more likely to be poor.
Women
Unmatched Unmatched Standard Standard Count Count Questionnaire Technique Questionnaire Technique χ2 P χ2 P (N = 507), (N = 216), (N = 519), (N = 207), b c d b Value Factor Value Value Factorc Valued No. (%) No. (%) No. (%) No. (%) 30 (14.0)
27 (13.3)
0.1
0.9
.785
36 (7.1)
81 (15.6)
18.3
2.2
< .001
131 (61.2)
115 (55.7)
1.4
0.9
.239
252 (50.1)
287 (55.4)
2.9
1.1
.090
151 (70.6)
106 (51.8)
15.7
0.7
< .001
337 (66.7)
347 (67.0)
0.0
1.0
.929
38 (17.8)
56 (27.0)
5.3
1.5
.022
56 (11.1)
29 (5.6)
9.9
0.5
.002
21 (9.8)
0 (0.0)
20.3
0.0
< .001
24 (4.8)
47 (9.1)
7.3
1.9
.007
a
Valid percentages are used in this table, so the denominator for each item may not reflect the total sample randomized to this condition. Percentage endorsement for the standard questionnaire (SQ) condition was reported directly. Percentage endorsement for the unmatched count technique (UCT) condition was calculated based on the excess endorsement above the SQ condition baseline. c The “factor” score is derived by dividing the UCT percentage by the SQ percentage. The “2.2” for Question 1 indicates that women in the UCT condition were 2.2 times as likely to admit that they think breastfeeding in some public places should be against the law, compared to women in the SQ condition. d P value is for χ2 test for independence. b
UCT condition were less likely to endorse Question 5 (“I think women who breastfeed in public are more likely to be poor”) than their counterparts in the SQ condition.
Discussion Our study results indicate that, for some questions investigating attitudes toward public breastfeeding, participants are more likely to indicate negative attitudes when in the UCT condition compared to direct questioning. This was consistent with our hypothesis that social desirability bias may be guiding responses to sensitive questions about breastfeeding in public. The goal of the UCT method is to increase perceived anonymity among participants responding to sensitive questions with the aim of reducing social desirability bias. However, the predicted effect was not found across all questions and differed by gender, race, and parental status.
In the overall sample, Question 1 (“I think breastfeeding in some public settings should be against the law”) received significantly higher endorsement by those in the UCT condition compared to the SQ condition, indicating that this question is subject to social desirability bias. Upon stratification by gender, this result held only for the female group, with women in the UCT condition being more than twice as likely to endorse the belief as women in the SQ condition. This suggests greater social pressure on women to oppose legal restrictions on breastfeeding in public places. When stratified by race, this result held only for whites, possibly indicating a similar pressure on whites. Although Question 2 (“I think children who are old enough to walk and talk should not be breastfed in public”) did not differ by method in the overall sample, when stratified by parental status, higher endorsement was found among nonparents in the UCT condition compared to the SQ condition. This difference may reflect an increased sensitivity
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Lippitt et al Table 4. Percentage of People Who Agreed with the Questions of Interest, by Parent Status.a Parent
Survey Question 1. I think breastfeeding in some public settings should be against the law. 2. I think children who are old enough to walk and talk should not be breastfed in public. 3. I think that women who breastfeed in public should cover themselves. 4. I think that seeing a woman breastfeeding in public can be sexually arousing. 5. I think women who breastfeed in public are more likely to be poor.
Not Parent
Unmatched Unmatched Standard Standard Count Count Questionnaire Technique Questionnaire Technique χ2 P χ2 P (N = 482), (N = 212), (N = 487), (N = 208), b c d b Value Factor Value Value Factorc Valued No. (%) No. (%) No. (%) No. (%) 19 (9.0)
12 (5.6)
1.6
0.6
.206
47 (9.8)
91 (18.6)
15.9
1.9
< .001
100 (47.6)
91 (44.0)
0.6
0.9
.453
247 (57.1)
297 (60.9)
1.5
1.1
.045
155 (73.1)
130 (62.6)
5.4
0.9
.020
316 (65.8)
310 (63.9)
0.4
1.0
.533
18 (8.6)
19 (9.1)
0.1
1.1
.803
75 (15.6)
70 (14.3)
0.3
0.9
.605
8 (3.8)
36 (17.4)
20.2
4.6
< .001
38 (7.9)
9 (1.9)
19.2
0.2
< .001
a
Valid percentages are used in this table, so the denominator for each item may not reflect the total sample randomized to this condition. Percentage endorsement for the standard questionnaire (SQ) condition was reported directly. Percentage endorsement for the unmatched count technique (UCT) condition was calculated based on the excess endorsement above the SQ condition baseline. c The “factor” score is derived by dividing the UCT percentage by the SQ percentage. The “1.9” for Question 1 indicates that nonparents in the UCT condition were 1.9 times as likely to admit that they think breastfeeding in some public places should be against the law, compared to nonparents in the SQ condition. d P value is for χ2 test for independence. b
related to breastfeeding older children in public among those who lack personal experience raising a child. It is interesting that men were significantly more likely to endorse Question 4 (“I think that seeing a woman breastfeeding in public can be sexually arousing”) in the UCT condition, but women were significantly more likely to endorse this question in the SQ condition. This finding indicates an interaction with gender and may show that men feel that they cannot admit overtly that they find public breastfeeding sexually arousing, whereas women are actually more likely to admit this overtly than anonymously. This finding in the female population could be due to the lack of clarity of the question (ie, some may have assumed that the question referred to men’s perception of breastfeeding as sexually
arousing rather than personal perception). Past research on attitudes toward breastfeeding by gender shows mixed results, indicating that further research is needed on this relationship.21 The UCT method shows potential for clarifying the differences in attitudes toward breastfeeding by gender by reducing social desirability bias. When we stratified by gender, race, and parental status, we found significantly different endorsement rates between UCT and SQ. Women, non-whites, and parents were much more likely to endorse Question 5 (“I think women who breastfeed in public are more likely to be poor”) in the UCT group than in the SQ group, suggesting that these groups feel greater pressure to conceal their perspective that breastfeeding in public is related to poverty compared to their
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Table 5. Percentage of People Who Agreed with the Questions of Interest, by Race.a White
Survey Question 1. I think breastfeeding in some public settings should be against the law. 2. I think children who are old enough to walk and talk should not be breastfed in public. 3. I think that women who breastfeed in public should cover themselves. 4. I think that seeing a woman breastfeeding in public can be sexually arousing. 5. I think women who breastfeed in public are more likely to be poor.
Non-White
Unmatched Unmatched Standard Standard Count Count Questionnaire Technique Questionnaire Technique χ2 P χ2 P (N = 156), (N = 566), (N = 169), (N = 554), b c d b Value Factor Value Value Factorc Valued No. (%) No. (%) No. (%) No. (%) 50 (8.8)
88 (15.8)
12.8
1.8
< .001
16 (10.3)
23 (13.8)
0.9
1.3
.343
300 (53.3)
298 (54.0)
0.0
1.0
.840
82 (52.9)
105 (61.9)
2.8
1.2
.093
380 (67.1)
342 (61.9)
3.3
0.9
.070
107 (69.5)
111 (66.3)
0.4
1.0
.513
65 (11.5)
56 (10.2)
0.5
0.9
.472
31 (19.9)
23 (13.7)
2.3
0.7
.130
29 (5.1)
0 (0.0)
28.2
0.0
< .001
17 (11.0)
40 (23.5)
9.0
2.1
.003
a
Valid percentages are used in this table, so the denominator for each item may not reflect the total sample randomized to this condition. Percentage endorsement for the standard questionnaire (SQ) condition was reported directly. Percentage endorsement for the unmatched count technique (UCT) condition was calculated based on the excess endorsement above the SQ condition baseline. c The “factor” score is derived by dividing the UCT percentage by the SQ percentage. The “1.8” for Question 1 indicates that whites in the UCT condition were 1.8 times as likely to admit that they think breastfeeding in some public places should be against the law, compared to whites in the SQ condition. d P value is for χ2 test for independence. b
counterparts. Although stratifying our results by gender, race, and parental status revealed significant differences in endorsement rates of certain questions between UCT and SQ, these differences were not always in the expected direction. Men in the SQ group were more likely to respond positively to Question 5 and Question 3 (“I think that women who breastfeed in public should cover themselves”) than men in the UCT group. This significant decrease in endorsement in the UCT group may indicate that this was not a sensitive question for men, such that they actually preferred to respond overtly rather than anonymously. A similar counterintuitive result was found among parents, who showed higher rates of endorsement of the “cover
themselves” question in the SQ condition as compared to the UCT condition. Unexpected results such as these may also indicate a context effect, that is, a tendency to endorse research questions more or less based on their positioning within the context of the decoy questions in the UCT group. However, we cannot parse out the influence of context within this dataset. This potential limitation is discussed further below.
Strengths and Limitations By testing the UCT method to assess attitudes toward breastfeeding practices, this study expands on the tools available
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Lippitt et al for research in this area and enables researchers to obtain more accurate responses to sensitive questions regarding negative perceptions of breastfeeding in public. Considering the many benefits of breastfeeding for both mother and infant,2,22 and the lack of knowledge and negative attitudes surrounding breastfeeding in the United States,23 the measurement advantages associated with using the UCT methodology are particularly salient. Other data on attitudes toward breastfeeding have been collected through several methods, including mail,9 telephone,7 and in-person7 administration. Our findings suggest that the UCT method—as administered via web-based survey—may improve reporting of sensitive issues, such as attitudes toward breastfeeding in public. We would expect the UCT method to be even more effective in increasing accuracy of reporting sensitive topics using more direct survey modes (eg, in-person). These strengths notwithstanding, our study has several limitations. A potential limitation of the UCT is the possibility that the decoy statements affect the participant’s attitude toward the question of interest. In the case of this study, we included decoy questions in each set relating to perspectives on gun control. It is possible that participants who were strongly opposed to gun control measures may have reacted by underendorsing all UCT questions in an effort to clearly communicate their lack of endorsement for the statements related to gun control. This may have resulted in a context effect in the UCT group and systematic underendorsement of some breastfeeding questions in this group. However, given that we observed a distribution of endorsement rates of the decoy questions in both conditions, this possibility is minimized. In addition, this study was designed to assess the use of the UCT method for measuring responses to sensitive questions on attitudes toward breastfeeding in public, rather than to assess attitudes toward breastfeeding more generally. Therefore, we caution against broad application of our findings regarding attitudes toward breastfeeding, since this construct was not evaluated by the questionnaire. As previous research has shown, the UCT method allows for only dichotomous responses, thus limiting our ability to compare these results with existing surveys that use a Likert scale style with multiple response options.24 Finally, we were not able to control for individual-level variables such as age because the UCT endorsement rates are estimated for the entire participant group, and not at the individual level. It is important to note that we were not able to collect data on the actual breastfeeding experiences or practices of our participants, which would be useful information for assessing attitudes toward breastfeeding. Future studies should collect information on breastfeeding experiences and analyze the relationship between personal experience and sensitivity around attitudes toward breastfeeding. Future research should also explore gender to determine whether attitudes of male and female parents differ from those of nonparents.
Implications Despite limitations, this research is important because it tests an innovative methodology for improving measurement of attitudes toward breastfeeding. A better understanding of the societal perspectives on breastfeeding could contribute to more nuanced public health policies, programs, and clinical recommendations for improving breastfeeding practices. To our knowledge, this is the first study to test the UCT method for measuring attitudes toward breastfeeding. The UCT method shows promise for improving estimates of negative attitudes toward breastfeeding, since the current research in this area is likely distorted by social desirability bias.2 In particular, this method may be useful for assessing male partner attitudes toward breastfeeding, which is an important predictor of a mother’s decision to breastfeed.6
Conclusion This study used an innovative questionnaire methodology, the UCT, to increase the perceived anonymity of a webbased survey on attitudes toward breastfeeding in public. The increase in perceived anonymity afforded by the UCT led to significantly higher endorsement of some negative attitudes toward breastfeeding in public, which raises questions about the quality of existing data on this topic. The effects of perceived anonymity may operate differently within different demographic sectors. The direction of the effects found here was not always consistent with hypotheses, and future research is needed to fully explore the various dimensions of attitudes toward breastfeeding. The UCT method shows promise for improving the accuracy of reporting of attitudes toward breastfeeding in public. Acknowledgments For their support in the development of the survey tool, we would like to thank Dr Debbie Humphries, Dr Rafael Perez-Escamilla, Dr Mary Alice Lee, Dr Mayur Desai, and Gogi Grewal.
Declaration of Conflicting Interests The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The authors received no financial support for the research, authorship, and/or publication of this article.
References 1. Taylor JS, Risica PM, Geller L, Kirtania U, Cabral HJ. Duration of breastfeeding among first-time mothers in the United States: results of a national survey. Acta Paediatr. 2006;95(8):980-984. 2. Persad MD, Mensinger JL. Maternal breastfeeding attitudes: association with breastfeeding intent and socio-demographics among urban primiparas. J Community Health. 2008;33(2):53-60.
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3. Stanton RW. A road map for change: ensuring that women have breastfeeding support. J Perinat Educ. 2011;20(3):130-133. 4. Furman LM, Banks EC, North AB. Breastfeeding among highrisk inner-city African-American mothers: a risky choice? Breastfeed Med. 2013;8(1):58-67. 5. Arora S, McJunkin C, Wehrer J, Kuhn P. Major factors influencing breastfeeding rates: mother’s perception of father’s attitude and milk supply. Pediatrics. 2000;106(5):e67. 6. Johnson AM, Correll A, Greene JF, Hein D, McLaughlin T. Barriers to breastfeeding in a resident clinic. Breastfeeding Med. 2013;8(3):273-276. 7. Pollock CA, Bustamante-Forest R, Giarratano G. Men of diverse cultures: knowledge and attitudes about breastfeeding. J Obstet Gynecol Neonatal Nurs. 2002;31(6):673-679. 8. Li R, Rock VJ, Grummer-Strawn L. Changes in public attitudes toward breastfeeding in the United States, 1999-2003. J Am Diet Assoc. 2007;107(1):122-127. 9. HealthStyles survey—breastfeeding practices: 2010. Centers for Disease Control and Prevention website. http://www.cdc. gov/breastfeeding/data/healthstyles_survey/survey_2010.htm. Updated December 2, 2013. Accessed February 26, 2014. 10. Fein SB, Labiner-Wolfe J, Shealy KR, Li R, Chen J, GrummerStrawn LM. Infant Feeding Practices Study II: study methods. Pediatrics. 2008;122(suppl 2):S28-S35. 11. Waruru AK, Nduati R, Tylleskär T. Audio computer-assisted self-interviewing (ACASI) may avert socially desirable responses about infant feeding in the context of HIV. BMC Med Inform Decis Mak. 2005;5(1):24. 12. Kloeblen-Tarver AS, Thompson NJ, Miner KR. Intent to breast-feed: the impact of attitudes, norms, parity, and experience. Am J Health Behav. 2002;26(3):182-187. 13. Kuklinski JH, Sniderman PM, Knight K, et al. Racial prejudice and attitudes toward affirmative action. Am J Pol Sci. 1997;41(2):402-419.
14. Streb MJ, Burrell B, Frederick B, Genovese MA. Social desirability effects and support for a female American president. Public Opin Q. 2008;72(1):76-89. 15. Conley D, McCabe BJ. Body mass index and physical attractiveness: evidence from a combination image-alteration/list experiment. Sociol Methods Res. 2011;40(1):6-31. 16. LaBrie JW, Earleywine M. Sexual risk behaviors and alcohol: higher base rates revealed using the unmatched-count technique. J Sex Res. 2000;37(4):321-326. 17. Coutts E, Jann B. Sensitive questions in online surveys: experimental results for the randomized response technique (RRT) and the unmatched count technique (UCT). Sociol Methods Res. 2011;40(1):169-193. 18. Dalton DR, Wimbush JC, Daily CM. Using the unmatched count technique (UCT) to estimate base rates for sensitive behavior. Pers Psychol. 1994;47(4):817-829. 19. Vittes KA, Sorenson SB, Gilbert D. High school stu dents’ attitudes about firearms policies. J Adolesc Health. 2003;33(6):471-478. 20. Zung W, Cavenar J. Assessment scales and techniques. In: Kutash IL, ed. Handbook of Stress and Anxiety. San Francisco, CA: Jossey-Bass; 1980:348-363. 21. Acker M. Breast is best . . . but not everywhere: ambivalent sexism and attitudes toward private and public breastfeeding. Sex Roles. 2009;61(7-8):476-490. 22. James D, Dobson B. American Dietetic Association. Position of the American Dietetic Association: promoting and supporting breastfeeding. J Am Diet Assoc. 2005;105(5): 810-818. 23. Li R, Fridinger F, Grummer-Strawn L. Public perceptions on breastfeeding constraints. J Hum Lact. 2002;18(3):227-235. 24. Lavender JM, Anderson DA. Effect of perceived anonymity in assessments of eating disordered behaviors and attitudes. Int J Eat Disord. 2009;42(6):546-551.
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