Journal of Genetic Counselin~ Vol. 4, No. 2, 1995
A Comparison of Two Approaches to Education About Carrier Testing for Cystic Fibrosis Katie P. Leonard, 1 L. Kay Bartholomew,2,5 Paul R. Swank,3 and Guy S. Parcel 4
We tested the efficacy of two types of educational materials for genetic counseling: a traditional information brochure and one adding a role model story. Brochures were alternated weekly at a prenatal genetics center. Subjects were asked to read the brochure and fill out a questionnaire covering demographics and variables from the health belief model (impact, barriers, motivation, susceptibility, knowledge, severity). A group of 409pregnant women and 251 male partners participated. Study design was quasiexperimenta~ using a post-test only comparison group. The brochure with modeling enhanced the perception of both risk and the severity of the disease and was inversely associated with the assessment of barriers, but did not directly impact on the decision to pursue testing; only 12% chose to be tested, with no significant differences between groups. While suggestive, the study is not confirmatory and should be repeated with a more heterogenous group of women. KEY WORDS: social cognitive theory; role modeling; health belief model; carrier screening; cystic fibrosis.
~Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas. Department of Health Education, Texas Children s Hospital, Houston, Texas. 3Department of Educational Psychology, College of Education, University of Houston, Houston, Texas. 4Center for Health Promotion Research and Development, University of Texas Houston Health Science Center, Houston, Texas. 5Correspondence should be directed to Kay Bartholomew, Department of Health Education, Texas Children's Hospital MC 4-3250, P.O. Box 300630, Houston, Texas 77230-0630. 97 1059-7700/95/0600-0097507.50/1 © 1995 National Society of Genetic Counselors, Inc.
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INTRODUCTION
Along with cloning the cystic fibrosis (CF) gene in 1989 (Riordan et al., 1989) came the controversy of whether or not to offer carder screening for CF to the general population and, if it is offered, how to implement it. Professional societies (American Society of Human Genetics, 1992; American College of Obstetrics and Gynecology, 1992) and respected researchers in the field (Biesecker et al., 1992; Kerem and Lynch, 1991; Wilfond and Fost, 1990) have opposed carder screening for individuals with a negative family history of the disease for various reasons, including lack of adequate educational materials to facilitate the genetic counseling process. The limited number of certified genetic counselors available to provide information and counseling (Wilfond and Fost, 1990) is another important consideration. The objective of this study was to test the efficacy of two types of educational materials intended to aid the process of genetic counseling regarding CF carrier screening. We were interested in whether we could enhance knowlede of cystic fibrosis and risk status more effectively using social cognitive theory generated role modeling vs. a more traditional informational approach.
CF Genetics Education
In pilot studies of CF carrier screening, education about the disease has primarily been accomplished by printed material (Mennie et al., 1992; Watson et al., 1992; Harris et al., 1992) with back-up by a health professional. In one study, high school students were given a lecture about CF carrier screening prior to testing (Kaplan et al., 1991). Bekker et aI. (1993) used passive (mailed information) and active (personal contact) methods to educate adults about CF carrier screening. They found the highest screening rate when an individual was personally approached and offered immediate testing. Studies assessing people's knowledge of and attitudes toward CF and CF carrier screening have been done in several different populations prior to any genetic testing. Botkin and Alemagno (1992) educated 306 pregnant women in Ohio about CF using a questionnaire. Of the 214 questionnaires that were returned, 78% reported having heard of CE The women in their study appeared to have read the printed information about CF and to have understood it enough for the majority to answer several questions about CF correctly. Another study of two groups of 216 adults at a dental
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clinic (Magnay et al., 1992) revealed that most of the participants had little knowledge of the problems people with CF encounter. In one group, less than half of the people surveyed recognized any of the major symptoms of CE A similar lack of knowledge was ascertained in a group of 385 adults in Belgium with no training or particular knowledge of genetics (Decruyenaere et al., 1992). Fifty-nine percent had heard of CF but only 38% could list one salient feature of the condition. Just over 10% of respondents knew that a gene defect played a key role in the disease and that CF was an autosomal recessive disease. There is a substantial worldwide experience in the use of populationbased carder screening to provide families with options for the prevention of autosomal recessive generic disorders. In reporting their Sardinian experience with carrier screening for beta-thalassemia, Cao et al. (1984 and 1989) describe using several different means to educate the population (1.5 million people in 1989) about the ongoing program. They met with community leaders, health professionals, and parents' associations, and also educated the population through the schools, mass media, and distribution of educational leaflets in doctors' offices, family planning clinics, and marriage registry offices. The majority of couples learned of the screening through the mass media, midwives, and marriage registries. The educational leaflets contained general information about the disease, where testing was available, and that prenatal diagnosis of the condition was available. Carrier screening for q~y-Sachs disease has employed many of the same tactics as the beta-thalassemia program. The first Tay-Sachs population screening program in the United States was undertaken after 14 months of preparation, including education through printed material, mass media, and religious and medical counseling (Kaback and O'Brien, 1973). In contrast, the experience with carder screening for sickle hemoglobin and other hemoglobinopathies has not always been a positive one. This experience was reviewed in an editorial by Bowman (1991). He states that many of the initial "educational b r o c h u r e s . . . w e r e replete with misinformarion" (p. 433). Rowley and co-workers have also described their screening program for hemoglobinopathies (Rowley et al., 1991a,b; Loader et al., 1991). With the help of providers of prenatal care, all pregnant women were screened for hemogiobinopathies at their first visit. Only one of 19 centers chose to obtain informed consent from the patients, so it is unclear ff any pre-screening education was done. Women found to be carriers were educated by the use of a videotape that explained carrier risk in easily understood terms and that modeled appropriate concern by the "patient" in the film; the women then received genetic counseling.
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Predictors of Carrier Testing The health belief model of health behavior has been found to predict participation in genetic screening (Rowley et al., 1991b). The relevant variables from the model are: (1) perception of susceptibility to disease; (2) perception of seriousness of the disease; (3) benefits of taking preventive action (or belief in the effectiveness of preventive action) balanced against costs (including social, psychological, and reproductive costs) of taking the action; and (4) cues to action (stimuli that bring the beliefs into focus and foster the intention to act). The patient information interventions in the study reported here targeted the health belief variables of risk of carrier status for CF, susceptibility of future children to the disease, seriousness of the disease in terms of burden, severity of the disease in relation to other pediatric conditions, and relative costs and benefits of the screening. The materials themselves were designed to serve as cues to action, and the appropriate actions (e.g., participation in testing) were available immediately to the subjects. Use of Social Cognitive Models Loader's use of patient models to impart information about carrier status is an example of the application of social cognitive theory to educational interventions in genetics (Loader et al., 1991). While the health belief model is useful for describing relevant variables that must be addressed in an educational intervention, it does not itself suggest which teaching-learning strategies to pursue. For guidance in educational methodology, we used social cognitive theory (also known as social learning theory). Social cognitive theory (Bandura, 1986) suggests that modeling (observational learning) can influence both behavioral capability and cognition. In this case, modeling was used in the intervention to develop behavioral capability for obtaining genetic testing and to influence cognitions (i.e., perceptions of susceptibility, seriousness, and cost/benefit). It is important to note that using social cognitive models to improve attention to information, behavioral capability and assessments of susceptibility, seriousness and cost is not persuasion (i.e., guiding people to take a particular course of action). Whether the messages important in educational interventions for genetic screening are best delivered by similar or dissimilar models is not clear. There is evidence that the effectiveness of modeling is positively influenced when the person presenting the information is similar to the
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proposed adopters of the behavior. The more dissimilar the two people, the less likely adoption is to occur (Rogers, 1983). This has particular relevance in medical issues, as medical care providers are usually better educated, often in a different socioeconomic class, and hold positions of respect and authority within society that make them dissimilar to their patients.
Study Questions In this study we addressed the following questions: Would the use of an educational role model with characteristics similar to the subject affect the subject's knowledge of the risk of being a carrier of the CF gene and of future children having the disease (susceptibility), seriousness of the disease in terms of its demands on the family, severity in comparison to other pediatric diseases, and cost/benefit of the test? Would it affect their motivation to be tested and whether they received testing? In addition, we examined the relations among the variables, to test whether the health belief model was predictive of the decision to have carrier testing.
METHODS Sample For four and one-haft months during 1992, people seen at a prenatal genetics center in a large metropolitan medical center were asked to read an information brochure on CF carrier screening and fill out a questionnaire that included personal data and questions regarding CE From a total of 409 women, 79.3% had appointments for pre-amniocentesis or CVS genetic counseling due to advanced maternal age (defined as 33 years and older). A total of 660 subjects participated: 409 females, 251 male partners of female subjects. The ages for the 657 subjects who responded to that question ranged from 17 to 52, with a mean age of 35.6 years. TWo thirds of the females were accompanied by their partners while 99% of the males were. Most were married (96% of the males and 92% of the females), white (85% of the males, 83% of the females), and well educated (87% of the males and 82% of the females had at least some college). Almost all the respondents lived with their partners (98% of the males, 93% of the females).
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Educational Intervention Two brochures were developed. The traditional informational brochure included information on the disease and the risk of being a carder, treatments for CF, its inheritance, and the availability and sensitivity of carrier screening for CF (87% carder detection rate at the time of the study). The role model brochure included this traditional information plus a story, interspersed throughout, of a family whose second child was affected with CE
Study Design We used a quasiexperimental, post-test only comparison group design. When people arrived for their appointments, they were asked by the receptionist to participate in the study by reading a brochure and answering the questionnaire. Subjects were assigned to the role modeling brochure group or the traditional informational brochure group based on their appointment date. Brochures were alternated weekly in clinic. While not random sampling, the procedure had the advantage of being relatively simple to implement without introducing any recognizable bias.
Questionnaire A questionnaire was developed to assess the subjects' knowledge of CF and of the risk of having a child with CF, previous experience with CF, and variables from the health belief model. Variables measured include seriousness in terms of impact on parents and family (items 13-15), barriers to carrier testing (2 parts of item 16), motivation to know carrier status (1 part of item 16), perceived personal risk (susceptibility, item 12 and 1 part of item 16), knowledge of the chances of having a child with CF (items 17-22), and severity (a subscale on the seriousness of CF compared to other pediatric diseases). (Fig. 1). In order to asess the perceived severity of the disease, a pair-comparison scaling procedure was used. A list of 20 relatively well-known diseases was generated by a multidisciplinary group of health care providers, including two physicians. The diseases ranged in seriousness from chicken pox to AIDS. Each disease was then paired against each of the other 19 diseases giving a total of 190 comparisons. In a pilot study 40 graduate students in a college of education were asked to compare each pair of diseases in terms of their seriousness. Responses were then scaled using the Law of Comparative Judgement (Guilford, 1954). Finally, nine diseases representing approximately
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Fig. 1. Cystic Fibrosis carrier testing questionnaire.
We are trying to evaluate if our CF brochure is helpful to our patients. Your answers axe confidential and will only be used to help us assist our patients better. Thank you for your help. l)emographics a 1. Your age 4.
7.
2. Your sex _ _
Marital status married single divorced widower
Are you:
3. Is your partner with you today? Yes
5. Ethnic/racial ancestry White African American Hispanic Asian Other
livingwith your partner
8. Have you known anyone with CF?
No
6. Years of school completed less than 9 years 9-11 years 12 years (high school graduate) some education beyond high school college graduate post college education
livingseparately Yes
No
9. Has anyone in your or your partner's family had CF?
Yes
No
Possibly,I'm not sure
10. Did you read the brochure about CF carder testing?
Yes
No
Partially
Previous knowledge 11. Before you read the brochure, how much did you know about CF?
Nothing
Perceived risk (suseeptib'dity) 12. How would you rate chance of having a child with CF?
Very likely
Seriousness 13. How much of an emotional strain do you think it would be to have a child with CF?
Very little
1
1
A lot 2
3
4
5 No chance
2
3
4
5 Very much
1
2
3
4
5
14. How much do you think taking care of a child with CF would affect you?
1
2
3
4
5
15. How much do you think a child with CF would affect your family relationships?
1
2
3
4
5
Here are some items that might affect how likely you would be to have would each one affect you? Barr/ers Have little effect 16. The expense of the text. 1 2 The discomfort of having blood drawn 1 2 Likelihood of being a carrier 1 2
Motivations Wanting to know if I am a CF carder
1
2
CF carrier testing. How
3 3 3
4 4 4
3
4
Know/edge What would be a couple's risk of having a child with CF in the following cases? 17. If both partners have positive CF carrier test results, their risk is: very high, and much higher than the general population higher than for the general population but still fairly low a little bit lower than for the general population very low and much lower than for the general population absolutely zero
Have big effect 5 5 5 5
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Fig. 1. Continued 18.
If one partner has a positive CF carrier test result and the other has a negative result, their risk is: very high, and much higher than for the general population higher than for the general population but still fairly low a little bit lower than for the general population very low and much lower than for the general population absolutely zero
19.
If both partners have negative CF carrier test results, their risk is: very high, and much higher than for the general population higher than for the general population but still fairly low a little bit lower than for the general population very low and much lower than for the general population absolutely zero
20.
When both partners are CF carriers, what is the chance that their child will have CF? 1 chance in 1 (all their children will have CF) 1 in 2 (a 50/50 chance) 1 in 4 (a 25% chance) 1 in 25 (a 4% chance)
21.
When both partners have negative CF carrier test results, what is the chance that they could still have a baby with CF? lin4 1 in50 1 in 2,500 1 in 100,000 0%
22.
When a person has no history of CF in his or her family, what is that person's chance of being a CF carrier? lin4 1 in 25 1 in 100 1 in 2,500
Sever/ty 23.
Mark a point on the line that indicates how serious you feel CF is compared to the other diseases listed. Leukemia Cerebral palsy Sickle cell anemia Diabetes Rheumatic fever Glaucoma Asthma Mumps Chicken pox
aSubject labels were not included in the original questionnaire; they are provided here for easier reference.
equal steps from 1 to 10 were selected, excluding CE Subjects in the current study were asked to specify how serious they considered CF to be, compared to the set of scaled diseases as shown in Fig. 1. Scale values were used for the analysis but were not listed on the scale completed by subjects. For ex-
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ample, if a person stated that they thought CF was as serious as leukemia then they received a severity score of 1. ff they felt it was as serious as sickle cell anemia then they received a value of 3. If a point between two diseases was selected then it received a value halfway between the two disease values.
Statistical Analysis Descriptive and chi-square statistics were calculated in order to identify potential gender differences in the variables. To take into account correlations among variables, a loglinear models analysis (logistic regression) was used to determine which variables predicted whether or not subjects chose CF carrier testing. In addition a general linear model (GLM) was performed to test the relation of type of brochure to the knowledge and belief variables. Dependent variables included in the GLM regression model were knowledge, severity scale, seriousness of impact, barriers, motivation and type of brochure. GLM was performed on both male and female data separately while data from female subjects only were used in the logistic regressions except that, when the male subject accompanying the female had the testing done, it was considered as a test for the female. Predictor variables included in the initial logistic regression model were knowledge, age, type of brochure, seriousness of impact, severity scale, barriers, and motivation. The dependent variable was the decision to have the test. Variables which did not contribute were dropped from the analysis. The final model includes all variables which were significant at p < .10 plus the variable of brochure type; the latter was retained because of its pertinence to the research question. In order to explore relations among variables, a path analysis was done. Path analysis is a procedure for solving simultaneous linear regression equations and is a tool for investigating complex interrelations between sets of variables. In order to accomplish this analysis the researcher must start from a hypothesized model which depicts the expected relations among the measured variables. The initial hypothesized model is depicted in Fig. 2.
RESULTS
Descriptive Statistics and Chi-Square Most subjects reported not knowing anyone with CF (88% of the males and 84% of the females) and in most cases knew of no one in their families with CF (97% of the males, 98% of the females). Most had read the bro-
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/ / / ] ~ Knowledge //
/l
Form of Brochure
Age
I Previous Knowledg
Fig. 2. Initial model hypothesized for the path analysis. Dashes represent hypothesized relationships that did not appear.
chure prior to completing the questionnaire (95% of the males, 94% of the females). Neither males nor females showed any statistically significant relation between type of brochure and their decision to have carrier screening. A larger proportion of those who read the brochure with modeling opted to have the testing done (12% of the females and 13% of the males, as compared to 8.6% of both genders who read the more traditional brochure), but this difference was not statistically significant. Males and females tended to respond similarly to the questions of knowledge, susceptibility, and barriers, although females tended to rate CF as more serious in terms of its impact than males (12.4 to 11.6 on the cumulative score from the seriousness ratings) and more severe (3.5 to 3.7 on the severity scale). Knowledge scores ranged from zero to six for both males and females with the mean knowledge being 3.9, or 65% correct, for both genders. All subjects rated their previous knowledge as slight (mean = 2.0 for females, 1.9 for males) and their susceptibility low (mean
Two Approaches to Carrier Testing Education
107
= 2.1 for females and 2.0 for males). Motivation ("wanting to know ff I'm a carrier" and "likelihood of being a carrier") was rated more likely than expense and discomfort to affect their decision about testing by both males and females (2.9 to 3.2).
General Linear Models The type of brochure had no direct significant effects on the responses of the male subjects; there were some differences for the female subjects. Those females who read the brochure with role models considered themselves as somewhat more likely to have a child with CF than did females reading the more traditional brochure (F(1, 395) = 4.61). (Throughout this paper, all p < 0.10 unless otherwise indicated.) They also indicated that the likelihood of being a carrier would have more effect on them than did females reading the more traditional brochure (F(1, 386) = 5.33).
Logistic Regression The variable which added most to the prediction of likelihood of having carrier testing was knowledge (Z2 (1) = 14.09), followed by the expense barrier (Z2 (1) = 5.37). Age (Z 2 (1) ---- 2.77) and the variables of wanting to know (X2 = 2.99) and likelihood of being a carrier (Z2 (1) = 3.26) were marginally related. The type of brochure was not related to the decision to have testing.
Path Analysis The initial model hypothesized for the path analysis (Fig. 2) allowed all endogenous (the hypothesized causes within the model) variables to be functions of the demographic variables (age and previous knowledge of CF) and the type of brochure. Knowledge, perceived risk (susceptibility), seriousness, and severity were considered to be functions of only type of brochure and demographics. Motivation to know personal carrier status was hypothesized to be a function of knowledge, personal risk, seriousness, and severity of the disease (in addition to demographics and type of brochure). Also in addition to demographics and type of brochure, barriers to testing were considered a function of knowledge and the decision to have testing done was hypothesized to be a direct function of motivation and an inverse function of barriers. (Fig. 2; see Table I for t-test values.) While this model had an acceptable Goodness of Fit Index (GFI +.978), the chi-square ratio
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Table I. Hypothesized Structural Equation Model a Perceived risk Seriousness
Knowledge Form Age Prev. know. Knowledge Per. risk Seriousness Severity Motivation Barriers
Severity
-2.25
Motivation Barriers
Test
2.22 -1.67
1.66
-2.95 ---
----
-1.66 1.72
. . . . . .
. . .
. . . . . .
. . . . . .
.
. . .
1.87 2.98 4.69 .
. . .
. .
4.35 -2.99
at-tests for the parameters from the hypothesized structural equation model. Dashes represent no hypothesized relationship. Blanks indicate hypothesized relationships that did not appear (see also Fig. 2).
was almost three and the model suffered from a significant lack of fit (chisquare (14) = 47.02; p < .011). Examination of the model residuals indicated that errors in estimating the relations between severity and seriousness of the disease, between severity and the motivation to be tested, between knowledge and severity, and between knowledge and whether or not the test was done were larger than is generally acceptable. Therefore, an additional model (Fig. 3; see Table II for t-test values) was considered which added paths from seriousness to severity, from knowledge to severity, and from knowledge to whether or not the testing was done. In addition, the path from severity to motivation was dropped as this coefficient was not significant. The reformulated model showed an excellent fit to the data (chisquare (12) = 13.10; p > .05) with a GFI of .994. The largest standardized residuals were less than 2, which also indicates a good fit to the data. Examination of the parameter estimates indicated that seriousness and severity of the disease are significantly related (t = -4.89; t is negative since on the severity scale one is the most severe). Knowledge was marginally related to severity (t = 1.76; one-tailed test) while barriers were more strongly but inversely related to knowledge (t = -2.95). Thus the more knowledge a subject had the less likely the barriers were to play a role in their decision to be tested. Motivation to be tested was directly related to the perceived seriousness of the disease ( t = 4.46), the perceived personal risk (t = 2.92), and knowledge (t = 1.96) The subjects' decisions to have testing were directly
109
Two Approaches to Carrier Testing Education Table H. Revised Structural Model a Perceived risk
Knowledge Form Age Prev. know. Knowledge Per. risk Seriousness Severity Motivation Barriers
Seriousness
Severity
-2.25
Motivation Barriers
-1.80 1.67
-. -. . .
-.
-.
-. . .
1.76
. -. . .
. . .
-4.89 . . .
. . .
1.96 2.92 4.47 .
Test
2.22 -1.67
t.67
-2.95 ---
2.86 --4.08 -2.58
at-tests for the parameters from the revised structural equation model. Dashes represent no hypothesized relationship. Blanks indicate hypothesized relationships that did not appear (see also Fig. 3).
[
Form of Brochure
Age
Previous Knowledge
Fig. 3. Reformulated model for path analysis. Dashes represent hypothesized relationships that did not appear.
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Leonard, Bartholomew, Swank, and Parcel
related to their knowledge about CF risk (t = 2.86) and their motivation to be tested and was inversely related to the perceived barriers. The effects of the type of brochure related to personal risk (t = -2.25) perception of the severity of the disease, and inversely to barriers (t = 2.22). Thus, those who received the brochure with modeling were more likely to perceive a greater risk of having a child with CF and more likely to perceive the disease as being more severe. At the same time they were less likely to see barriers as a preclusion of the test. Age was directly related to perceived seriousness (t = 1.67; one tailed) and whether or not they were tested (t = 1.67; one tailed) and inversely related to barriers (t = -1.67; one tailed). Thus older subjects were likely to see the disease as more serious, and were more likely to be tested, but were less likely to worry about barriers to testing. Previous knowledge was unrelated to any of the endogenous variables.
DISCUSSION
Educational materials used in population carrier screening programs have traditionally relied on the provision of information. In our study, we compared a traditional informational brochure to one using methods based on social cognitive theory. Both brochures where designed to address the risk or susceptibility of the reader to CF, the seriousness of the impact of CF on the family, severity of the disease compared to other pediatric illnesses, motivation to know carrier status, and perception of barriers to getting the test. The results indicate that in our sample the brochure with the modeling enhanced the patient's perception of both the risk of having a child with CF and the severity of the disease. Reading the social cognitive version also was inversely associated with assessment of barriers. This is a potentially important finding of this pilot study since the addition of role models (a social cognitive theory derived method) to a traditional genetic counseling brochure is a relatively simple, inexpensive intervention that can apparently change the impact of the educational message. Genetic counselors consider an important part of their role to be the explanation of risk (Pearn, 1973; Wertz et al., 1986, 1992). It is also well documented that once risk is numerically presented by a genetic counselor a subjective assessment of that risk occurs, and these subjective assessments of risk can guide the reproductive decision making of the client (e.g., Wertz et al., 1986). Subjective assignment of risk seems to depend on many variables (e.g., the nature of the outcome of the risk, the actual numeric risk, the issues discussed in the counseling session, and the availablity of an example of a negative outcome) and may vary systematically between coun-
Two Approaches to Carrier Testing Education
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selors and clients with counselors assigning greater subjective risk (Wertz et al., 1986). The systematic attempt on the part of the counselor to elicit either more positive or more negative subjective evaluation of risk is ethically suspect and yet it is this subjective response that is the outcome of the counseling process. Therefore, an educational vehicle that incorporates an example of risking a negative outcome can assist the genetic counselor not only in explaining risk but in enabling the client to interpret the risk. Our results did not indicate that the educational method had a direct impact on the decision to pursue testing. Only approximately 12% of the subjects had the test and this percentage did not vary significantly between groups depending on the type of brochure. However, the results of the path analysis did indicate that the type of brochure was significantly related to health belief model variables (severity, perceived risk (susceptibiliy) and barriers). In turn, perception of barriers was inversely related to the subject's decision to have the test performed and greater perceived risk was associated with greater motivation to know carder status which was associated with having the test. The other variables that were related to having the test done were age (older subjects were more likely to have the test) and knowledge about the risk of being a CF carder (the more knowledgeable were more likely to have the test). It should be noted that the model for the path analysis was changed in response to empirical data and so the analysis cannot be considered confirmatory. The current model should be replicated on a new set of data. Twelve percent is a small proportion of women actually choosing to have the test done as compared to other studies of CF carrier testing. In the pilot study in Edinburgh (Mennie et al., 1992), 200 women were sent an information leaflet with their booking appointment and asked to discuss testing with their partner. The testing was then further discussed at their first appointment. This method gave the woman a chance to consider the information prior to the day of the test. Of the eligible patients, 73% chose to be screened. In our study, the timing of the discussion of testing may have been a deterent to testing. The offer of the testing was made to pregnant women at the time of a visit to discuss genetic testing primarily indicated by advanced maternal age. When evaluating the level of interest for CF carrier screening, Botkin and Alemagno (1992) found that 84% of the 214 women in their study would have done CF carrier screening prior to a pregnancy, but only 69% would choose to be screened during a pregnancy. Decruyenaere et aL (1992) found that the majority (86%) of 385 people they surveyed thought CF carder screening should be offered prior to pregnancy. In a study of 175 recent parents and their attitudes toward carrier screening, 48% thought testing at the beginning of a pregnancy was best (Green, 1992).
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This pilot study was limited to a homogeneous group: Caucasian, middie-class, and educated, and the response to testing was limited. The results of this study are suggestive of the power of the social cognitive theory educational method and the study should be repeated on a more heterogeneous group of women who have more time in which to study their options and make a decision of whether or not to be tested.
REFERENCES American College of Obstetrics and Gynecology (1992) Current status of cystic fibrosis carrier screening [committee opinion], lnt J Gynecol Obstet 39:143-149. American Society of Human Genetics (1992) Statement of the American Society of Human Genetics on cystic fibrosis carrier screening. A m J Hum Genet 51:1443-1444. Bandura A (1986) Social Foundations of Thought and Action: A Social Cognitive Theory. Englewood Cliffs: Prentice-Hall. Bekker H, Modell M, Denniss G, Silver A, Mathew C, Bobrow M, Marteau T (1993) Uptake of cystic fibrosis testing in primary care: supply push or demand pull? BCJ 306:1584-1586. Biesecker L, Bowles-Biesecker B, Collins F, Kaback M, Wilfond B (1992) General population screening for cystic fibrosis is premature. A m J Hum Genet 50(2):438-439. Botkin JR, Alemagno S (1992) Carrier screening for cystic fibrosis: A pilot study of the attitudes of pregnant women. A m J Pub Health 82(5):723-725. Bowman JE (1991) Prenatal screening for hemoglobinopathies [invited editorial]. A m J Hum Genet 48:433-438. Cao A, Pintus L, Lecca U, Olla G, Cossu P, Rosatelli C, Galanello R (1984) Control of homozygous beta-thalassemia by carder screening and antenatal diagnosis in Sardinians. Clin Genet 26:12-22. Cao A, RosateUi C, Galanello tL Monni G, Gila G, Cossu P, Ristaldi MS (1989) The prevention of thalassemia in Sardinia. Clin Genet 36:277-285. Decruyenaere M, Evers-Kiebooms G, Denayer L, Van den Berghe H (1992) Cystic fibrosis: Community knowledge and attitudes towards carrier screening and prenatal diagnosis. Clin Genet 41:189-196. Green JM (1992) Principles and practicalities of carrier screening: Attitudes of recent parents. J Med Genet 29(5):313-319. Guilford JP (1954) Psychometric Methods (2nd Ed.). New York: McGraw-Hill. Harris HJ, Scotcher D, Hartley N, Wallace A, Craufurd D, Harris R (1992) Cystic fibrosis carrier screening at first diagnosis of pregnancy in general practice [letter]. Lancet 339:1539. Kaback M, O'Brien J (1973) Tay-Sachs: Prototype for prevention of genetic disease. Hosp Pract March:107-116. Kaplan F, Chow C, Striver CR (1991) Cystic fibrosis carrier testing by DNA analysis: A pilot study of attitudes among participants. A m J Hum Gen 49(1):240-242. Kerem E, Lynch A (1991) Screening for cystic fibrosis: ethical and social issues. A m Rev Respir Dis 143:457-460. Loader S, Sutera CA, Walden M, Kozyra A, Rowley PT (1991) Prenatal screening for hemoglobinopathies. II. Evaluation of counseling. A m J Hum Genet 48:447-451. Magnay D, Wilson O, El Hait S, Balhamar M, Burn J (1992) Carrier testing for cystic fibrosis: Knowledge and attitudes within a local community. J R Coil Physicians Lond 26(1):69-70. Mennie ME, Liston WA, Brock DJH (1992) Prenatal cystic fibrosis carrier testing: Designing an information leaflet to meet the specific needs of the target population. J Med Genet 29:308-312.
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Pearn JH (1973) Patients' subjective interpretation of risks offered in genetic counseling. J Med Genet 10:129-134. Riordan JR, Rommens JM, Kerem B, Aion N, Rozmahel R, Grzelczak Z, Zielenski J, Lok S, Ptavsic N, Chou J, Drumm M, Iannuzzi M, Collins F, Tsui L (1989) Identification of the cystic fibrosis gene: Cloning and characterization of complementary DNA. Science 245:1066-1073. Rogers EM (1983) Diffusion o f Innovations. New York: The Free Press. Rowley PT, Loader S, Sutera CJ, Walden M, Kozyra A (1991a) Prenatal screening for hemoglobinopathies. I. A prospective regional trial. A m J Hum Genet 48:439-446. Rowley PT, Loader S, Sutera CJ, Walden M, Kozyra A (1991b) Prenatal screening for hemoglobinopathies. III. Applicability of the health belief model. A m J Hum Genet 48:452-459. Watson EK, Mayall ES, Lamb J, Chapple J, WiUiamson R (1992) Psychological and social consequences of community carrier screening programme for cystic fibrosis. Lancet 340:217-220. Wertz DC, Sorenson JR, Heeren TC (1986) Clients' interpretation of risks provided in genetic counseling. J Hum Genet 39:253-264. Wertz DC, Janes SR, Rosenfield JM, Erbe RW (1992) Attitudes toward the prenatal diagnosis of cystic fibrosis: Factors in decision making among affected families. A m J Hum Genet 50:1077-1085. Wilfond BS, Fost N (1990) The cystic fibrosis gene: Medical and social implications for heterozygote detection. JAMA 263(20): 2777-2783.
A Comparison of Two Approaches to Education About Carrier Testing for Cystic Fibrosis Katie P. Leonard, 1 L. Kay Bartholomew,2,5 Paul R. Swank,3 and Guy S. Parcel 4
We tested the efficacy of two types of educational materials for genetic counseling: a traditional information brochure and one adding a role model story. Brochures were alternated weekly at a prenatal genetics center. Subjects were asked to read the brochure and fill out a questionnaire covering demographics and variables from the health belief model (impact, barriers, motivation, susceptibility, knowledge, severity). A group of 409pregnant women and 251 male partners participated. Study design was quasiexperimenta~ using a post-test only comparison group. The brochure with modeling enhanced the perception of both risk and the severity of the disease and was inversely associated with the assessment of barriers, but did not directly impact on the decision to pursue testing; only 12% chose to be tested, with no significant differences between groups. While suggestive, the study is not confirmatory and should be repeated with a more heterogenous group of women. KEY WORDS: social cognitive theory; role modeling; health belief model; carrier screening; cystic fibrosis.
~Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas. Department of Health Education, Texas Children s Hospital, Houston, Texas. 3Department of Educational Psychology, College of Education, University of Houston, Houston, Texas. 4Center for Health Promotion Research and Development, University of Texas Houston Health Science Center, Houston, Texas. 5Correspondence should be directed to Kay Bartholomew, Department of Health Education, Texas Children's Hospital MC 4-3250, P.O. Box 300630, Houston, Texas 77230-0630. 97 1059-7700/95/0600-0097507.50/1 © 1995 National Society of Genetic Counselors, Inc.
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INTRODUCTION
Along with cloning the cystic fibrosis (CF) gene in 1989 (Riordan et al., 1989) came the controversy of whether or not to offer carder screening for CF to the general population and, if it is offered, how to implement it. Professional societies (American Society of Human Genetics, 1992; American College of Obstetrics and Gynecology, 1992) and respected researchers in the field (Biesecker et al., 1992; Kerem and Lynch, 1991; Wilfond and Fost, 1990) have opposed carder screening for individuals with a negative family history of the disease for various reasons, including lack of adequate educational materials to facilitate the genetic counseling process. The limited number of certified genetic counselors available to provide information and counseling (Wilfond and Fost, 1990) is another important consideration. The objective of this study was to test the efficacy of two types of educational materials intended to aid the process of genetic counseling regarding CF carrier screening. We were interested in whether we could enhance knowlede of cystic fibrosis and risk status more effectively using social cognitive theory generated role modeling vs. a more traditional informational approach.
CF Genetics Education
In pilot studies of CF carrier screening, education about the disease has primarily been accomplished by printed material (Mennie et al., 1992; Watson et al., 1992; Harris et al., 1992) with back-up by a health professional. In one study, high school students were given a lecture about CF carrier screening prior to testing (Kaplan et al., 1991). Bekker et aI. (1993) used passive (mailed information) and active (personal contact) methods to educate adults about CF carrier screening. They found the highest screening rate when an individual was personally approached and offered immediate testing. Studies assessing people's knowledge of and attitudes toward CF and CF carrier screening have been done in several different populations prior to any genetic testing. Botkin and Alemagno (1992) educated 306 pregnant women in Ohio about CF using a questionnaire. Of the 214 questionnaires that were returned, 78% reported having heard of CE The women in their study appeared to have read the printed information about CF and to have understood it enough for the majority to answer several questions about CF correctly. Another study of two groups of 216 adults at a dental
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clinic (Magnay et al., 1992) revealed that most of the participants had little knowledge of the problems people with CF encounter. In one group, less than half of the people surveyed recognized any of the major symptoms of CE A similar lack of knowledge was ascertained in a group of 385 adults in Belgium with no training or particular knowledge of genetics (Decruyenaere et al., 1992). Fifty-nine percent had heard of CF but only 38% could list one salient feature of the condition. Just over 10% of respondents knew that a gene defect played a key role in the disease and that CF was an autosomal recessive disease. There is a substantial worldwide experience in the use of populationbased carder screening to provide families with options for the prevention of autosomal recessive generic disorders. In reporting their Sardinian experience with carrier screening for beta-thalassemia, Cao et al. (1984 and 1989) describe using several different means to educate the population (1.5 million people in 1989) about the ongoing program. They met with community leaders, health professionals, and parents' associations, and also educated the population through the schools, mass media, and distribution of educational leaflets in doctors' offices, family planning clinics, and marriage registry offices. The majority of couples learned of the screening through the mass media, midwives, and marriage registries. The educational leaflets contained general information about the disease, where testing was available, and that prenatal diagnosis of the condition was available. Carrier screening for q~y-Sachs disease has employed many of the same tactics as the beta-thalassemia program. The first Tay-Sachs population screening program in the United States was undertaken after 14 months of preparation, including education through printed material, mass media, and religious and medical counseling (Kaback and O'Brien, 1973). In contrast, the experience with carder screening for sickle hemoglobin and other hemoglobinopathies has not always been a positive one. This experience was reviewed in an editorial by Bowman (1991). He states that many of the initial "educational b r o c h u r e s . . . w e r e replete with misinformarion" (p. 433). Rowley and co-workers have also described their screening program for hemoglobinopathies (Rowley et al., 1991a,b; Loader et al., 1991). With the help of providers of prenatal care, all pregnant women were screened for hemogiobinopathies at their first visit. Only one of 19 centers chose to obtain informed consent from the patients, so it is unclear ff any pre-screening education was done. Women found to be carriers were educated by the use of a videotape that explained carrier risk in easily understood terms and that modeled appropriate concern by the "patient" in the film; the women then received genetic counseling.
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Predictors of Carrier Testing The health belief model of health behavior has been found to predict participation in genetic screening (Rowley et al., 1991b). The relevant variables from the model are: (1) perception of susceptibility to disease; (2) perception of seriousness of the disease; (3) benefits of taking preventive action (or belief in the effectiveness of preventive action) balanced against costs (including social, psychological, and reproductive costs) of taking the action; and (4) cues to action (stimuli that bring the beliefs into focus and foster the intention to act). The patient information interventions in the study reported here targeted the health belief variables of risk of carrier status for CF, susceptibility of future children to the disease, seriousness of the disease in terms of burden, severity of the disease in relation to other pediatric conditions, and relative costs and benefits of the screening. The materials themselves were designed to serve as cues to action, and the appropriate actions (e.g., participation in testing) were available immediately to the subjects. Use of Social Cognitive Models Loader's use of patient models to impart information about carrier status is an example of the application of social cognitive theory to educational interventions in genetics (Loader et al., 1991). While the health belief model is useful for describing relevant variables that must be addressed in an educational intervention, it does not itself suggest which teaching-learning strategies to pursue. For guidance in educational methodology, we used social cognitive theory (also known as social learning theory). Social cognitive theory (Bandura, 1986) suggests that modeling (observational learning) can influence both behavioral capability and cognition. In this case, modeling was used in the intervention to develop behavioral capability for obtaining genetic testing and to influence cognitions (i.e., perceptions of susceptibility, seriousness, and cost/benefit). It is important to note that using social cognitive models to improve attention to information, behavioral capability and assessments of susceptibility, seriousness and cost is not persuasion (i.e., guiding people to take a particular course of action). Whether the messages important in educational interventions for genetic screening are best delivered by similar or dissimilar models is not clear. There is evidence that the effectiveness of modeling is positively influenced when the person presenting the information is similar to the
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proposed adopters of the behavior. The more dissimilar the two people, the less likely adoption is to occur (Rogers, 1983). This has particular relevance in medical issues, as medical care providers are usually better educated, often in a different socioeconomic class, and hold positions of respect and authority within society that make them dissimilar to their patients.
Study Questions In this study we addressed the following questions: Would the use of an educational role model with characteristics similar to the subject affect the subject's knowledge of the risk of being a carrier of the CF gene and of future children having the disease (susceptibility), seriousness of the disease in terms of its demands on the family, severity in comparison to other pediatric diseases, and cost/benefit of the test? Would it affect their motivation to be tested and whether they received testing? In addition, we examined the relations among the variables, to test whether the health belief model was predictive of the decision to have carrier testing.
METHODS Sample For four and one-haft months during 1992, people seen at a prenatal genetics center in a large metropolitan medical center were asked to read an information brochure on CF carrier screening and fill out a questionnaire that included personal data and questions regarding CE From a total of 409 women, 79.3% had appointments for pre-amniocentesis or CVS genetic counseling due to advanced maternal age (defined as 33 years and older). A total of 660 subjects participated: 409 females, 251 male partners of female subjects. The ages for the 657 subjects who responded to that question ranged from 17 to 52, with a mean age of 35.6 years. TWo thirds of the females were accompanied by their partners while 99% of the males were. Most were married (96% of the males and 92% of the females), white (85% of the males, 83% of the females), and well educated (87% of the males and 82% of the females had at least some college). Almost all the respondents lived with their partners (98% of the males, 93% of the females).
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Educational Intervention Two brochures were developed. The traditional informational brochure included information on the disease and the risk of being a carder, treatments for CF, its inheritance, and the availability and sensitivity of carrier screening for CF (87% carder detection rate at the time of the study). The role model brochure included this traditional information plus a story, interspersed throughout, of a family whose second child was affected with CE
Study Design We used a quasiexperimental, post-test only comparison group design. When people arrived for their appointments, they were asked by the receptionist to participate in the study by reading a brochure and answering the questionnaire. Subjects were assigned to the role modeling brochure group or the traditional informational brochure group based on their appointment date. Brochures were alternated weekly in clinic. While not random sampling, the procedure had the advantage of being relatively simple to implement without introducing any recognizable bias.
Questionnaire A questionnaire was developed to assess the subjects' knowledge of CF and of the risk of having a child with CF, previous experience with CF, and variables from the health belief model. Variables measured include seriousness in terms of impact on parents and family (items 13-15), barriers to carrier testing (2 parts of item 16), motivation to know carrier status (1 part of item 16), perceived personal risk (susceptibility, item 12 and 1 part of item 16), knowledge of the chances of having a child with CF (items 17-22), and severity (a subscale on the seriousness of CF compared to other pediatric diseases). (Fig. 1). In order to asess the perceived severity of the disease, a pair-comparison scaling procedure was used. A list of 20 relatively well-known diseases was generated by a multidisciplinary group of health care providers, including two physicians. The diseases ranged in seriousness from chicken pox to AIDS. Each disease was then paired against each of the other 19 diseases giving a total of 190 comparisons. In a pilot study 40 graduate students in a college of education were asked to compare each pair of diseases in terms of their seriousness. Responses were then scaled using the Law of Comparative Judgement (Guilford, 1954). Finally, nine diseases representing approximately
Two A p p r o a c h e s to Carrier Testing Education
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Fig. 1. Cystic Fibrosis carrier testing questionnaire.
We are trying to evaluate if our CF brochure is helpful to our patients. Your answers axe confidential and will only be used to help us assist our patients better. Thank you for your help. l)emographics a 1. Your age 4.
7.
2. Your sex _ _
Marital status married single divorced widower
Are you:
3. Is your partner with you today? Yes
5. Ethnic/racial ancestry White African American Hispanic Asian Other
livingwith your partner
8. Have you known anyone with CF?
No
6. Years of school completed less than 9 years 9-11 years 12 years (high school graduate) some education beyond high school college graduate post college education
livingseparately Yes
No
9. Has anyone in your or your partner's family had CF?
Yes
No
Possibly,I'm not sure
10. Did you read the brochure about CF carder testing?
Yes
No
Partially
Previous knowledge 11. Before you read the brochure, how much did you know about CF?
Nothing
Perceived risk (suseeptib'dity) 12. How would you rate chance of having a child with CF?
Very likely
Seriousness 13. How much of an emotional strain do you think it would be to have a child with CF?
Very little
1
1
A lot 2
3
4
5 No chance
2
3
4
5 Very much
1
2
3
4
5
14. How much do you think taking care of a child with CF would affect you?
1
2
3
4
5
15. How much do you think a child with CF would affect your family relationships?
1
2
3
4
5
Here are some items that might affect how likely you would be to have would each one affect you? Barr/ers Have little effect 16. The expense of the text. 1 2 The discomfort of having blood drawn 1 2 Likelihood of being a carrier 1 2
Motivations Wanting to know if I am a CF carder
1
2
CF carrier testing. How
3 3 3
4 4 4
3
4
Know/edge What would be a couple's risk of having a child with CF in the following cases? 17. If both partners have positive CF carrier test results, their risk is: very high, and much higher than the general population higher than for the general population but still fairly low a little bit lower than for the general population very low and much lower than for the general population absolutely zero
Have big effect 5 5 5 5
Leonard, Bartholomew, Swank, and Parcel
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Fig. 1. Continued 18.
If one partner has a positive CF carrier test result and the other has a negative result, their risk is: very high, and much higher than for the general population higher than for the general population but still fairly low a little bit lower than for the general population very low and much lower than for the general population absolutely zero
19.
If both partners have negative CF carrier test results, their risk is: very high, and much higher than for the general population higher than for the general population but still fairly low a little bit lower than for the general population very low and much lower than for the general population absolutely zero
20.
When both partners are CF carriers, what is the chance that their child will have CF? 1 chance in 1 (all their children will have CF) 1 in 2 (a 50/50 chance) 1 in 4 (a 25% chance) 1 in 25 (a 4% chance)
21.
When both partners have negative CF carrier test results, what is the chance that they could still have a baby with CF? lin4 1 in50 1 in 2,500 1 in 100,000 0%
22.
When a person has no history of CF in his or her family, what is that person's chance of being a CF carrier? lin4 1 in 25 1 in 100 1 in 2,500
Sever/ty 23.
Mark a point on the line that indicates how serious you feel CF is compared to the other diseases listed. Leukemia Cerebral palsy Sickle cell anemia Diabetes Rheumatic fever Glaucoma Asthma Mumps Chicken pox
aSubject labels were not included in the original questionnaire; they are provided here for easier reference.
equal steps from 1 to 10 were selected, excluding CE Subjects in the current study were asked to specify how serious they considered CF to be, compared to the set of scaled diseases as shown in Fig. 1. Scale values were used for the analysis but were not listed on the scale completed by subjects. For ex-
Two Approaches to Carrier Testing Education
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ample, if a person stated that they thought CF was as serious as leukemia then they received a severity score of 1. ff they felt it was as serious as sickle cell anemia then they received a value of 3. If a point between two diseases was selected then it received a value halfway between the two disease values.
Statistical Analysis Descriptive and chi-square statistics were calculated in order to identify potential gender differences in the variables. To take into account correlations among variables, a loglinear models analysis (logistic regression) was used to determine which variables predicted whether or not subjects chose CF carrier testing. In addition a general linear model (GLM) was performed to test the relation of type of brochure to the knowledge and belief variables. Dependent variables included in the GLM regression model were knowledge, severity scale, seriousness of impact, barriers, motivation and type of brochure. GLM was performed on both male and female data separately while data from female subjects only were used in the logistic regressions except that, when the male subject accompanying the female had the testing done, it was considered as a test for the female. Predictor variables included in the initial logistic regression model were knowledge, age, type of brochure, seriousness of impact, severity scale, barriers, and motivation. The dependent variable was the decision to have the test. Variables which did not contribute were dropped from the analysis. The final model includes all variables which were significant at p < .10 plus the variable of brochure type; the latter was retained because of its pertinence to the research question. In order to explore relations among variables, a path analysis was done. Path analysis is a procedure for solving simultaneous linear regression equations and is a tool for investigating complex interrelations between sets of variables. In order to accomplish this analysis the researcher must start from a hypothesized model which depicts the expected relations among the measured variables. The initial hypothesized model is depicted in Fig. 2.
RESULTS
Descriptive Statistics and Chi-Square Most subjects reported not knowing anyone with CF (88% of the males and 84% of the females) and in most cases knew of no one in their families with CF (97% of the males, 98% of the females). Most had read the bro-
Leonard, Bartholomew, Swank, and Parcel
106
/ / / ] ~ Knowledge //
/l
Form of Brochure
Age
I Previous Knowledg
Fig. 2. Initial model hypothesized for the path analysis. Dashes represent hypothesized relationships that did not appear.
chure prior to completing the questionnaire (95% of the males, 94% of the females). Neither males nor females showed any statistically significant relation between type of brochure and their decision to have carrier screening. A larger proportion of those who read the brochure with modeling opted to have the testing done (12% of the females and 13% of the males, as compared to 8.6% of both genders who read the more traditional brochure), but this difference was not statistically significant. Males and females tended to respond similarly to the questions of knowledge, susceptibility, and barriers, although females tended to rate CF as more serious in terms of its impact than males (12.4 to 11.6 on the cumulative score from the seriousness ratings) and more severe (3.5 to 3.7 on the severity scale). Knowledge scores ranged from zero to six for both males and females with the mean knowledge being 3.9, or 65% correct, for both genders. All subjects rated their previous knowledge as slight (mean = 2.0 for females, 1.9 for males) and their susceptibility low (mean
Two Approaches to Carrier Testing Education
107
= 2.1 for females and 2.0 for males). Motivation ("wanting to know ff I'm a carrier" and "likelihood of being a carrier") was rated more likely than expense and discomfort to affect their decision about testing by both males and females (2.9 to 3.2).
General Linear Models The type of brochure had no direct significant effects on the responses of the male subjects; there were some differences for the female subjects. Those females who read the brochure with role models considered themselves as somewhat more likely to have a child with CF than did females reading the more traditional brochure (F(1, 395) = 4.61). (Throughout this paper, all p < 0.10 unless otherwise indicated.) They also indicated that the likelihood of being a carrier would have more effect on them than did females reading the more traditional brochure (F(1, 386) = 5.33).
Logistic Regression The variable which added most to the prediction of likelihood of having carrier testing was knowledge (Z2 (1) = 14.09), followed by the expense barrier (Z2 (1) = 5.37). Age (Z 2 (1) ---- 2.77) and the variables of wanting to know (X2 = 2.99) and likelihood of being a carrier (Z2 (1) = 3.26) were marginally related. The type of brochure was not related to the decision to have testing.
Path Analysis The initial model hypothesized for the path analysis (Fig. 2) allowed all endogenous (the hypothesized causes within the model) variables to be functions of the demographic variables (age and previous knowledge of CF) and the type of brochure. Knowledge, perceived risk (susceptibility), seriousness, and severity were considered to be functions of only type of brochure and demographics. Motivation to know personal carrier status was hypothesized to be a function of knowledge, personal risk, seriousness, and severity of the disease (in addition to demographics and type of brochure). Also in addition to demographics and type of brochure, barriers to testing were considered a function of knowledge and the decision to have testing done was hypothesized to be a direct function of motivation and an inverse function of barriers. (Fig. 2; see Table I for t-test values.) While this model had an acceptable Goodness of Fit Index (GFI +.978), the chi-square ratio
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Leonard, Bartholomew, Swank, a n d Parcel
Table I. Hypothesized Structural Equation Model a Perceived risk Seriousness
Knowledge Form Age Prev. know. Knowledge Per. risk Seriousness Severity Motivation Barriers
Severity
-2.25
Motivation Barriers
Test
2.22 -1.67
1.66
-2.95 ---
----
-1.66 1.72
. . . . . .
. . .
. . . . . .
. . . . . .
.
. . .
1.87 2.98 4.69 .
. . .
. .
4.35 -2.99
at-tests for the parameters from the hypothesized structural equation model. Dashes represent no hypothesized relationship. Blanks indicate hypothesized relationships that did not appear (see also Fig. 2).
was almost three and the model suffered from a significant lack of fit (chisquare (14) = 47.02; p < .011). Examination of the model residuals indicated that errors in estimating the relations between severity and seriousness of the disease, between severity and the motivation to be tested, between knowledge and severity, and between knowledge and whether or not the test was done were larger than is generally acceptable. Therefore, an additional model (Fig. 3; see Table II for t-test values) was considered which added paths from seriousness to severity, from knowledge to severity, and from knowledge to whether or not the testing was done. In addition, the path from severity to motivation was dropped as this coefficient was not significant. The reformulated model showed an excellent fit to the data (chisquare (12) = 13.10; p > .05) with a GFI of .994. The largest standardized residuals were less than 2, which also indicates a good fit to the data. Examination of the parameter estimates indicated that seriousness and severity of the disease are significantly related (t = -4.89; t is negative since on the severity scale one is the most severe). Knowledge was marginally related to severity (t = 1.76; one-tailed test) while barriers were more strongly but inversely related to knowledge (t = -2.95). Thus the more knowledge a subject had the less likely the barriers were to play a role in their decision to be tested. Motivation to be tested was directly related to the perceived seriousness of the disease ( t = 4.46), the perceived personal risk (t = 2.92), and knowledge (t = 1.96) The subjects' decisions to have testing were directly
109
Two Approaches to Carrier Testing Education Table H. Revised Structural Model a Perceived risk
Knowledge Form Age Prev. know. Knowledge Per. risk Seriousness Severity Motivation Barriers
Seriousness
Severity
-2.25
Motivation Barriers
-1.80 1.67
-. -. . .
-.
-.
-. . .
1.76
. -. . .
. . .
-4.89 . . .
. . .
1.96 2.92 4.47 .
Test
2.22 -1.67
t.67
-2.95 ---
2.86 --4.08 -2.58
at-tests for the parameters from the revised structural equation model. Dashes represent no hypothesized relationship. Blanks indicate hypothesized relationships that did not appear (see also Fig. 3).
[
Form of Brochure
Age
Previous Knowledge
Fig. 3. Reformulated model for path analysis. Dashes represent hypothesized relationships that did not appear.
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Leonard, Bartholomew, Swank, and Parcel
related to their knowledge about CF risk (t = 2.86) and their motivation to be tested and was inversely related to the perceived barriers. The effects of the type of brochure related to personal risk (t = -2.25) perception of the severity of the disease, and inversely to barriers (t = 2.22). Thus, those who received the brochure with modeling were more likely to perceive a greater risk of having a child with CF and more likely to perceive the disease as being more severe. At the same time they were less likely to see barriers as a preclusion of the test. Age was directly related to perceived seriousness (t = 1.67; one tailed) and whether or not they were tested (t = 1.67; one tailed) and inversely related to barriers (t = -1.67; one tailed). Thus older subjects were likely to see the disease as more serious, and were more likely to be tested, but were less likely to worry about barriers to testing. Previous knowledge was unrelated to any of the endogenous variables.
DISCUSSION
Educational materials used in population carrier screening programs have traditionally relied on the provision of information. In our study, we compared a traditional informational brochure to one using methods based on social cognitive theory. Both brochures where designed to address the risk or susceptibility of the reader to CF, the seriousness of the impact of CF on the family, severity of the disease compared to other pediatric illnesses, motivation to know carrier status, and perception of barriers to getting the test. The results indicate that in our sample the brochure with the modeling enhanced the patient's perception of both the risk of having a child with CF and the severity of the disease. Reading the social cognitive version also was inversely associated with assessment of barriers. This is a potentially important finding of this pilot study since the addition of role models (a social cognitive theory derived method) to a traditional genetic counseling brochure is a relatively simple, inexpensive intervention that can apparently change the impact of the educational message. Genetic counselors consider an important part of their role to be the explanation of risk (Pearn, 1973; Wertz et al., 1986, 1992). It is also well documented that once risk is numerically presented by a genetic counselor a subjective assessment of that risk occurs, and these subjective assessments of risk can guide the reproductive decision making of the client (e.g., Wertz et al., 1986). Subjective assignment of risk seems to depend on many variables (e.g., the nature of the outcome of the risk, the actual numeric risk, the issues discussed in the counseling session, and the availablity of an example of a negative outcome) and may vary systematically between coun-
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selors and clients with counselors assigning greater subjective risk (Wertz et al., 1986). The systematic attempt on the part of the counselor to elicit either more positive or more negative subjective evaluation of risk is ethically suspect and yet it is this subjective response that is the outcome of the counseling process. Therefore, an educational vehicle that incorporates an example of risking a negative outcome can assist the genetic counselor not only in explaining risk but in enabling the client to interpret the risk. Our results did not indicate that the educational method had a direct impact on the decision to pursue testing. Only approximately 12% of the subjects had the test and this percentage did not vary significantly between groups depending on the type of brochure. However, the results of the path analysis did indicate that the type of brochure was significantly related to health belief model variables (severity, perceived risk (susceptibiliy) and barriers). In turn, perception of barriers was inversely related to the subject's decision to have the test performed and greater perceived risk was associated with greater motivation to know carder status which was associated with having the test. The other variables that were related to having the test done were age (older subjects were more likely to have the test) and knowledge about the risk of being a CF carder (the more knowledgeable were more likely to have the test). It should be noted that the model for the path analysis was changed in response to empirical data and so the analysis cannot be considered confirmatory. The current model should be replicated on a new set of data. Twelve percent is a small proportion of women actually choosing to have the test done as compared to other studies of CF carrier testing. In the pilot study in Edinburgh (Mennie et al., 1992), 200 women were sent an information leaflet with their booking appointment and asked to discuss testing with their partner. The testing was then further discussed at their first appointment. This method gave the woman a chance to consider the information prior to the day of the test. Of the eligible patients, 73% chose to be screened. In our study, the timing of the discussion of testing may have been a deterent to testing. The offer of the testing was made to pregnant women at the time of a visit to discuss genetic testing primarily indicated by advanced maternal age. When evaluating the level of interest for CF carrier screening, Botkin and Alemagno (1992) found that 84% of the 214 women in their study would have done CF carrier screening prior to a pregnancy, but only 69% would choose to be screened during a pregnancy. Decruyenaere et aL (1992) found that the majority (86%) of 385 people they surveyed thought CF carder screening should be offered prior to pregnancy. In a study of 175 recent parents and their attitudes toward carrier screening, 48% thought testing at the beginning of a pregnancy was best (Green, 1992).
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This pilot study was limited to a homogeneous group: Caucasian, middie-class, and educated, and the response to testing was limited. The results of this study are suggestive of the power of the social cognitive theory educational method and the study should be repeated on a more heterogeneous group of women who have more time in which to study their options and make a decision of whether or not to be tested.
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Pearn JH (1973) Patients' subjective interpretation of risks offered in genetic counseling. J Med Genet 10:129-134. Riordan JR, Rommens JM, Kerem B, Aion N, Rozmahel R, Grzelczak Z, Zielenski J, Lok S, Ptavsic N, Chou J, Drumm M, Iannuzzi M, Collins F, Tsui L (1989) Identification of the cystic fibrosis gene: Cloning and characterization of complementary DNA. Science 245:1066-1073. Rogers EM (1983) Diffusion o f Innovations. New York: The Free Press. Rowley PT, Loader S, Sutera CJ, Walden M, Kozyra A (1991a) Prenatal screening for hemoglobinopathies. I. A prospective regional trial. A m J Hum Genet 48:439-446. Rowley PT, Loader S, Sutera CJ, Walden M, Kozyra A (1991b) Prenatal screening for hemoglobinopathies. III. Applicability of the health belief model. A m J Hum Genet 48:452-459. Watson EK, Mayall ES, Lamb J, Chapple J, WiUiamson R (1992) Psychological and social consequences of community carrier screening programme for cystic fibrosis. Lancet 340:217-220. Wertz DC, Sorenson JR, Heeren TC (1986) Clients' interpretation of risks provided in genetic counseling. J Hum Genet 39:253-264. Wertz DC, Janes SR, Rosenfield JM, Erbe RW (1992) Attitudes toward the prenatal diagnosis of cystic fibrosis: Factors in decision making among affected families. A m J Hum Genet 50:1077-1085. Wilfond BS, Fost N (1990) The cystic fibrosis gene: Medical and social implications for heterozygote detection. JAMA 263(20): 2777-2783.
