AIDS Behav DOI 10.1007/s10461-015-1042-x
ORIGINAL PAPER
Mediation of an Efficacious HIV Risk Reduction Intervention for South African Men Ann O’Leary1 • John B. Jemmott III2 • Loretta S. Jemmott2 • Scarlett Bellamy2 Larry D. Icard3 • Zolani Ngwane4
•
Ó Springer Science+Business Media New York (outside the USA) 2015
Abstract ‘‘Men, Together Making a Difference!’’ is an HIV/STD risk-reduction intervention that significantly increased self-reported consistent condom use during vaginal intercourse compared with a health-promotion attentioncontrol intervention among men (N = 1181) in Eastern Cape Province, South Africa. The present analyses were designed to identify mediators of the intervention’s efficacy. The potential mediators were Social Cognitive Theory (SCT) constructs that the intervention targeted, including several aspects of condom-use self-efficacy, outcome expectancies, and knowledge. Mediation was assessed using a product-of-coefficients approach where an a path (the intervention’s effect on the potential mediator) and a b path (the potential mediator’s effect on the outcome of interest, adjusting for intervention) were estimated independently in a generalized estimating equations framework. Condom-use negotiation self-efficacy, technical-skill self-efficacy, and impulse-control self-efficacy were significant mediators. Although not mediators, descriptive norm and expected friends’ approval of condom use predicted subsequent self-reported condom use, whereas the expected approval of sexual partner did not. The present results suggest that HIV/STD risk-reduction interventions that draw upon SCT and that address self-efficacy to negotiate condom use, to apply condoms correctly, and to exercise sufficient control when sexually aroused to use & Ann O’Leary [email protected] 1
Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, 8 Corporate Square Blvd., Atlanta, GA 30329, USA
2
University of Pennsylvania, Philadelphia, PA, USA
3
Temple University, Philadelphia, PA, USA
4
Haverford College, Haverford, PA, USA
condoms may contribute to efforts to reduce sexual risk behavior among South African men. Future research must examine whether approaches that build normative support for condom use among men’s friends are also efficacious. Keywords HIV prevention Cluster-randomized trial South Africa Men Behavioral intervention Mediation
Introduction Many behavioral interventions contain multiple components, whose inclusion is often driven by the theoretical framework used to develop the interventions. Mediation analysis can reveal which components of an intervention were responsible for its effectiveness [1, 2]. In theory, the findings from a mediation analysis could be used to shorten the intervention to focus on only the efficacious components, potentially rendering the intervention more cost-effective. Several Social Cognitive Theory (SCT) [3] constructs, including self-evaluative outcome expectancy, hedonistic outcome expectancy, expected partner approval of condom use, and self-efficacy, mediated an intervention for low-income, urban patients from sexually transmitted disease (STD) clinics and primary care clinics [4]. Intention to use condoms mediated an HIV/STD risk-reduction intervention for college students [5], as well as one for STD clinic patients [6]. In a trial for HIV-infected gay and bisexual men, one factor that was not influenced by the intervention—personal responsibility to not infect others— was highly associated with behavior and behavior changes; this combination of results may explain why the intervention was not effective in reducing HIV transmission-risk behavior [7]. The effectiveness of an intervention for African American, inner-city women was mediated by expected partner reaction and condom-use self-efficacy in univariate analyses,
123
AIDS Behav
but only self-efficacy remained significant in a multivariate analysis [8]. In a trial with South African adolescents, the significant abstinence outcome was mediated by expected parental disapproval of the child being sexually active and self-efficacy to avoid sexual-risk situations [9]. Similarly, sex refusal self-efficacy as well as knowledge mediated an abstinence outcome for U.S. middle school students [10]. In another study of U.S. adolescents, frequency of communicating with male partners mediated an HIV risk-reduction intervention for adolescent girls [11]. ‘‘Men Together, Making a Difference’’ is an HIV/STD riskreduction intervention that was tested in a cluster-randomized controlled trial in Eastern Cape Province, South Africa [12]. Participants were South African men 18–45 years of age whose neighborhoods were randomized to receive either the HIV/STD risk-reduction intervention or a health promotion attention-control intervention. Each intervention, developed based on SCT integrated with extensive formative research with the population, consisted of three 2.5-h sessions of interactive exercises, games, brainstorming, role-playing, takehome assignments, group discussions, and videos implemented in small groups over a 3-week period. The primary outcome measure was self-reported consistent condom use. Accordingly, the HIV/STD risk-reduction intervention was designed to increase the men’s (a) self-efficacy, including the confidence that they could use condoms correctly, negotiate their use, and exercise sufficient control when sexually excited to use condoms; (b) outcome expectancies supporting condom use, including beliefs about the self-evaluative, hedonistic, and prevention consequences of using condoms; and (c) HIV/ STI risk-reduction knowledge. Data were collected at baseline, immediately post-, and 6 and 12 months post-intervention. More detailed descriptions of the interventions and methods can be found elsewhere [12, 13]. Generalized estimating equations (GEE) logistic regression analysis revealed that the HIV/STD risk-reduction intervention significantly increased self-reported consistent condom use averaged over 6- and 12-month follow-up assessments compared with the attention-control intervention, controlling for baseline consistent condom use and clustering of men within 44 neighborhoods [12]. In addition, the intervention’s efficacy in increasing condom use was not significantly different at the 6-month compared with 12-month follow-up. The present article reports analyses designed to identify which of several SCT constructs accounted for the efficacy of the intervention in increasing consistent condom use.
the study, more than 98 % of residents were Black Africans whose first language is isiXhosa. Assessment and intervention sessions were held at the University of Fort Hare in East London; transportation was provided to participants. Study protocols were approved by the Institutional Review Board (IRB) at the University of Pennsylvania, which was the designated IRB under the federal wide assurance of the University of Pennsylvania and the University of Fort Hare. We identified 206 neighborhoods defined as geographical clusters linked to census tracts, created matched pairs similar on the percentage isiXhosa-speaking, percentage married, percentage male, percentage unemployed, percentage living in informal dwellings, and population size, and randomly selected 22. One neighborhood within each pair was randomly assigned to either the HIV/STD risk-reduction intervention or to the health-promotion control intervention, which was of the same duration and format as the risk-reduction one. Support from the community leaders had been obtained prior to recruitment. Recruiters, who spoke isiXhosa, recruited men at different hours of the day and night, from a variety of venues. Men were eligible if they were aged 18–45, lived in one of the selected neighborhoods, had engaged in vaginal intercourse within the previous 90 days, and had a photo identification card or were willing to have their picture taken for identification purposes. Measures All measures were collected via audio computer-assisted self-interviewing (ACASI) on a laptop computer. The measures, which had been pilot-tested with 250 men, were available in isiXhosa (following translation and back translation from English), English, and a combination of isiXhosa (audio) and English (visual). Sexual Risk Behavior Outcome Consistent condom use during vaginal intercourse, the primary outcome for the study, was assessed by asking men who reported at least 1 vaginal intercourse act in the previous 90 days the number that were condom protected. If this number was equal to the total number of intercourse acts, the man was coded as practicing consistent condom use; if the reported number of condom-protected intercourse acts was less than his total number of intercourse acts, the man was coded as not practicing consistent condom use. Consistent condom use was assessed at baseline and 6 and 12 months following the interventions.
Methods Potential Mediators Methods for the study are described in detail elsewhere [12]. The study was conducted in Eastern Cape Province, South Africa from November 2007 to December 2010. In the area of
123
Table 1 presents the number of items, response format, and alphas for the potential mediators, all of which we have
AIDS Behav
employed in previous research. We assessed three types of outcome expectancy regarding condom use. Condom-use self-evaluative outcome expectancy is expected reactions of pride as a consequence of using condoms [4, 7, 14]. An example item from this scale is ‘‘I would feel good about myself if I used condoms.’’ Hedonistic condom-use outcome expectancy concerns the belief that sex is still pleasurable when condoms are used [4, 7, 8]. An example item is ‘‘If I used a condom, sex would feel as good.’’ Condomuse prevention outcome expectancy concerns the belief that condoms can prevent STDs, HIV, and pregnancy [15, 16]. An example of an item is ‘‘Condoms help prevent STDs.’’ We assessed four types of self-efficacy regarding condom use. Condom-use negotiation self-efficacy is the man’s belief that he can convince his partner to use condoms [5, 17]. An example of an item is ‘‘I can get my partner to use a condom, even if she doesn’t want to.’’ Condom-use technical skill self-efficacy is the man’s belief that he knows how to use condoms [8, 15, 17]. An example of an item is ‘‘I can use a condom, even if the room is dark.’’ Condom-use impulse control self-efficacy is the man’s belief that he can control himself sufficiently when sexually aroused to use a condom [15, 17]. An example item is ‘‘I can pause before sex in order to use a condom, even if I am already sexually aroused.’’ We also measured condom-use knowledge [8, 17]. An example of an item is ‘‘When a condom is put on the penis, a space should be left at the tip of the condom.’’ We assessed three theoretical variables that, though not targeted by the intervention, are constructs in our theoretical framework [3, 18]. Friends’ and sexual partners’ approval outcome expectancies were measured with two single items [17, 19]: ‘‘My friends would think it is okay
Table 1 Characteristics of theoretical constructs
for me to use a condom if I have sex in the next six months;’’ ‘‘My partner would think it is okay for me to use a condom if I have sex in the next six months.’’ Condomuse descriptive norm is the man’s belief regarding his closest friends’ use of condoms [18]. An example of an item is ‘‘How many of your 5 closest friends use condoms when they have vaginal intercourse.’’ Participants also completed measures of sociodemographic variables, the Cutting down, Annoyance by criticism, Guilty feeling, and Eye-openers (CAGE) questionnaire [20] which measures problem alcohol consumption, and measures of health-promotion behaviors and their potential mediators. Data Analysis We assessed mediation using a product-of-coefficients approach [2, 21] in which an a path denoted the effect of the intervention on the potential mediator at the immediate post-intervention assessment, a b path denoted the relation of the potential mediator to consistent condom use adjusted for the intervention, and the product of a and b (ab) quantifies the mediated effect of the intervention. The a paths were estimated in GEE models [22, 23] where the potential mediator was the outcome, with the intervention and the baseline of consistent condom use and the potential mediator as predictors. The b paths were estimated in GEE models with consistent condom use as the outcome and the intervention, potential mediator, time, and the baseline of consistent condom use and the potential mediator as predictors. We present two statistical evaluations of mediation, testing the null hypothesis that ab = 0 (i.e., no mediation): a Z statistic and corresponding p value [2] as
Construct
Number of items
Type of response
Alpha
Condom-use self-evaluative outcome expectancy
3
5-point Likert
0.76
Condom-use hedonistic outcome expectancy
6
5-point Likert
0.75
Condom-use prevention outcome expectancy
3
5-point Likert
0.82
Condom-use negotiation self-efficacy
5
5-point Likert
0.89
Condom-use technical skill self-efficacy
7
5-point Likert
0.89
Condom-use impulse control self-efficacy
3
5-point Likert
0.74
Condom-use knowledge
4
True/False
–
Condom-use descriptive norm
3
4-point Likert
0.75
Condom-use expected friends’ approval
1
5-point Likert
–
Condom-use expected partners’ approval
1
5-point Likert
–
Condom-use expected normative approval
2
5-point Likert
0.71
Ratings on the Likert scales could range from 1 (Disagree strongly) to 5 (Agree strongly) except for condom-use descriptive norm where the ratings could range from 1 (None of them) to 4 (All of them). The score was the mean of the ratings except for condom-use knowledge where the score was the sum of the number of items correctly answered. Alpha is Cronbach’s coefficient alpha for the post-intervention assessment of the construct, which was analyzed as the potential mediator
123
AIDS Behav
well as asymmetric confidence limits (ACL) for ab that accommodate the non-normal distribution of a product statistic [21]. All models were fit using a GEE approach, adjusting for the potential mediator and self-reported consistent condom use at baseline, the longitudinal correlation of measuring outcomes repeatedly over time, and clustering of men within 44 neighborhoods. We also performed moderated-mediation analyses testing whether the follow-up time affected the a paths (intervention 9 follow-up time interactions) or the b paths (potential mediator 9 follow-up time interactions) for each potential mediator. Here a significant interaction would indicate that the mediation of the intervention’s efficacy was different at the 6-month follow-up compared with the 12-month follow-up [24]. All hypotheses were tested using the two-sided, alpha = 0.05 significance criterion, and all were performed using SAS Version 9.
Results Sociodemographic characteristics, by intervention arm and overall, are given in Table 2. A total of 1181 men (mean age = 26.7 years; SD = 6.6) enrolled in the trial. Virtually all spoke isiXhosa as their home language. Few were married, but 80 % had a steady partner in the prior 3 months. Majorities of men were unemployed, had not completed high school, and were alcohol-dependent. Attendance at the intervention sessions was high: 1181 (100 %), 1171 (99.2 %), and 1165 (98.6 %) attended intervention sessions 1, 2, and 3, respectively. Retention at the follow-ups was excellent: 1140 or 96.5 % attended at least one of the two follow-up assessments, including 1093 (92.5 %) who attended the 6-month follow-up and 1106 (93.6 %) who attended the 12-month follow-up. The percentage attending at least one follow-up session did not differ in the HIV/STI risk-reduction intervention compared with the health-promotion control intervention or by baseline age group, high school education, unemployment, marital status, steady or casual partners, alcohol problems, or self-reported consistent condom use. Table 3 presents potential mediator and outcome summaries, by intervention, at each assessment point (i.e., baseline and 6 and 12 months post–intervention). Means and standard errors are presented for each potential mediator and the number and percentage of men reporting consistent condom use in the past 3 months. Table 4 displays the mediation results, including the estimated ICC for the ‘alpha’ path in the model. Specifically, this ICC was estimated treating the longitudinal mediator as the outcome in a model that included intervention, time and cluster (neighborhood). Results were the same using the Z test and the ACL approach, where mediation is indicated when the ACL does not contain
123
zero. As can be seen from the table, several of the selfefficacy variables were significant mediators of the intervention effect. Self-efficacy for condom negotiation, selfefficacy for technical skills in condom application, and self-efficacy for impulse control were all significant mediators. As the significant a paths indicate, the HIV/STD risk-reduction intervention increased each of these constructs compared with the health promotion attention-control intervention. Significant b paths indicate that increases in these constructs predicted higher odds of self-reported consistent condom use. In contrast, the outcome expectancies regarding condom use, including self-evaluative, hedonistic expectancies, and prevention outcome expectancy were not significant mediators; neither were availability self-efficacy, expected friends’ approval of condom use, expected partners’ approval, descriptive norm (the belief that one’s closest friends use condoms), or condom-use knowledge. Although the a paths were significant for all eight of these variables except descriptive norm, the b paths were significant for only two of them: descriptive norm and expected friends’ approval of condom use. There was no evidence that follow-up time moderated the alpha path or the beta path; therefore, the mediation of the intervention’s efficacy was not significantly different at the 6-month follow-up compared with the 12-month follow-up.
Discussion The present results indicate that SCT, a theory developed in the United States, is applicable and valuable even in distant cultures. Our previous work with South African adolescents established this as well [9, 25, 26]. In fact, mediation analysis of interventions’ efficacy is a particularly useful way to substantiate the relevance of theory to behavior [27]. The SCT mediators we identified here were instantiated in the intervention through interactive activities and skill-building activities to build self-efficacy. Significant mediators included self-efficacy to negotiate condom use, self-efficacy for condom-use technical skills, and self-efficacy for condom-use impulse control. Prevention expectancies, which are based on simple information regarding the effects of condoms on preventing pregnancy and STD, were not significant mediators. Relatedly, condom-use knowledge was not a significant mediator. In both cases, the alpha paths were significant, indicating that the intervention had the expected effects on the variables. However, the beta paths were not significant, indicating the variables did not predict increased condom use. The results for both of these theoretical constructs are consonant with the notion that information alone is not sufficient to change behavior [17].
AIDS Behav Table 2 Sociodemographic characteristics of neighborhoods and participating men by intervention condition at baseline, Eastern Cape Province, South Africa 2007–2010 Characteristic
HIV/STD Intervention
Health Control Intervention
Total
No. (%) isiXhosa home language
607/609 (99.7 %)
571/572 (99.8 %)
1178/1181 (99.8 %)
No. (%) married No. (%) steady partner in past 3 months
27/609 (4.4 %)
41/572 (7.2 %)
68/1181 (5.8 %)
494/609 (81.1 %)
451/572 (78.8 %)
945/1181 (80.0 %)
No. (%) casual partner in past 3 months
328/609 (53.9 %)
274/572 (47.9 %)
602/1181 (51.1 %)
No. (%) unemployed
425/609 (69.8 %)
368/572 (64.3 %)
793/1181 (67.1 %)
279/609 (45.8 %)
239/572 (41.8 %)
518/1181 (43.9 %)
377/609 (61.9 %)
330/572 (57.7 %)
707/1181 (59.9 %)
18–24
282/609 (46.3) %
273/572 (47.7 %)
555/1181 (47.0 %)
25–29
158/609 (25.9 %)
126/572 (22.0 %)
284/1181 (24.0 %)
30–45
169/609 (27.8 %)
173/572 (30.2 %)
342/1181 (29.0 %)
Own house or flat
115/609 (18.8) %
107/572 (18.7 %)
222/1181 (18.8 %)
Family’s house
369/609 (60.6 %)
361/572 (63.1 %)
730/1181 (61.8 %)
Partner’s house
19/609 (3.1) %
13/572 (2.3 %)
32/1181 (2.7 %)
Rented room
15/609 (2.5 %)
12/572 (2.1 %)
27/1181 (2.3 %)
Shack in someone else’s yard
91/609 (14.9 %)
79/572 (13.8 %)
170/1181 (14.3 %)
No. (%) completed high school No. (%) alcohol dependent No. (%) age (years) group
a
No. (%) housing circumstances
a
Based on a score of 2 or greater on the Cutting down, Annoyance by criticism, Guilty feeling, and Eye-openers (CAGE) questionnaire
Table 3 Potential mediator and outcome summaries at study time points for HIV/STD risk reduction (RR) and health promotion (HP) interventions Potential mediators (mean ± SE)
Baseline HP
RR
Immediate post
6-month
HP
HP
RR
12-month RR
HP
RR
Condom-use knowledge
3.09 ± 0.04
3.10 ± 0.03
3.16 ± 0.04
3.57 ± 0.03
3.05 ± 0.04
3.38 ± 0.03
3.12 ± 0.04
3.37 ± 0.04
Self-evaluative expectancy
4.04 ± 3.89
4.00 ± 0.03
4.13 ± 0.03
4.32 ± 0.02
4.10 ± 0.03
4.25 ± 0.03
4.03 ± 0.04
4.26 ± 0.03
Hedonistic expectancy
3.37 ± 0.03
3.35 ± 0.03
3.59 ± 0.03
4.06 ± 0.03
3.62 ± 0.03
3.90 ± 0.03
3.68 ± 0.03
3.93 ± 0.03
Prevention expectancy
4.38 ± 0.03
4.34 ± 0.03
4.30 ± 0.03
4.43 ± 0.03
4.36 ± 0.03
4.37 ± 0.03
4.23 ± 0.04
4.35 ± 0.03 2.77 ± 0.04
Descriptive norm
2.70 ± 0.04
2.75 ± 0.04
2.68 ± 0.04
2.82 ± 0.04
2.68 ± 0.04
2.83 ± 0.04
2.68 ± 0.04
Expected friend approval
4.05 ± 0.04
4.15 ± 0.04
4.01 ± 0.05
4.08 ± 0.04
3.89 ± 0.05
3.99 ± 0.05
3.74 ± 0.06
3.94 ± 0.05
Expected partner approval Available self-efficacy
3.98 ± 0.05 4.01 ± 0.03
4.05 ± 0.04 3.99 ± 0.03
4.07 ± 0.04 4.08 ± 0.03
4.11 ± 0.04 4.16 ± 0.02
3.88 ± 0.05 4.13 ± 0.03
4.05 ± 0.05 4.16 ± 0.02
3.87 ± 0.05 4.11 ± 0.03
4.01 ± 0.04 4.15 ± 0.03
Negotiation self-efficacy
4.04 ± 0.03
4.05 ± 0.03
4.11 ± 0.03
4.27 ± 0.02
4.10 ± 0.03
4.24 ± 0.02
4.06 ± 0.03
4.26 ± 0.02
Technical skill selfefficacy
3.86 ± 0.03
3.80 ± 0.03
3.95 ± 0.03
4.12 ± 0.02
3.95 ± 0.03
4.10 ± 0.03
3.98 ± 0.03
4.16 ± 0.03
Impulse control selfefficacy
3.46 ± 0.04
3.45 ± 0.04
3.66 ± 0.02
3.96 ± 0.03
3.63 ± 0.04
3.91 ± 0.03
3.68 ± 0.04
3.95 ± 0.03
211 (36.89)
248 (40.72)
211 (36.89)
248 (40.72)
182 (31.82)
216 (35.47)
177 (30.94)
207 (33.99)
Outcome N (%) Consistent condom use
Although increased by the intervention, hedonistic outcome expectancies and self-evaluative outcome expectancies also were not significant mediators as they did not
significantly predict consistent condom use. This is in contrast to a RCT in the United States reporting that hedonistic outcome expectancies and self-evaluative outcome
123
AIDS Behav Table 4 GEE mediation analysis of intervention effects (HIV/STD intervention versus health promotion intervention) fit to ‘consistent (100 %) condom use’ with causal and main partners (at 6- and 12-month follow-up) Potential mediator
ICC (a path)
a path ± SE (p value)a
b path ± SE (p value)b
Product ab (p value) [ACL]c
Condom-use knowledge
0.02
0.336 ± 0.040
-0.114 ± 0.150
-0.038
(\0.001)
(0.448)
(0.449)
0.175 ± 0.042
0.216 ± 0.156
0.038
(\0.001)
(0.166)
(0.188)
[-0.138, 0.061] Self-evaluative expectancy
0.02
[-0.019, 0.094] Hedonistic expectancy
0.02
0.391 ± 0.044 (\0.001)
0.252 ± 0.161 (0.119)
0.098 (0.124)
Prevention expectancy
0.01
0.139 ± 0.035
0.088 ± 0.129
0.012
(\0.001)
(0.494)
(0.501)
0.084 ± 0.052
0.370 ± 0.111
0.031
(0.102)
(0.001)
(0.142)
0.160 ± 0.071
0.200 ± 0.088
0.032
(0.024)
(0.023)
(0.108)
0.163 ± 0.065
0.203 ± 0.112
0.033
(0.013)
(0.070)
(0.144)
[-0.0027, 0.224]
[-0.024, 0.048] Descriptive norm
0.01
[-0.011, 0.073] Expected friends’ approval
0.01
[-0.007, 0.071] Available self-efficacy
0.01
[-0.011, 0.077] Expected partners’ approval
0.03
0.063 ± 0.030 (0.037)
0.043 ± 0.210 (0.836)
0.003 (0.837)
Negotiation self-efficacy
0.02
0.150 ± 0.037
0.455 ± 0.163
0.068
(\0.001)
(0.005)
(0.021)
[-0.023, 0.029]
[0.010, 0.127] Technical skill self-efficacy
0.02
0.175 ± 0.039
0.478 ± 0.194
0.083
(\0.001)
(0.014)
(0.031)
0.347 ± 0.051
0.348 ± 0.098
0.121
(\0.001)
(\0.001)
(0.002)
[0.007, 0.159] Impulse control self-efficacy
0.01
[0.045, 0.196]
expectancies mediated the effects of an HIV risk reduction intervention on condom use among urban low-income African American men and women [4]. While the indirect effects of the intervention through descriptive norm, expected friends’ approval of condom use, and expected sex partners’ approval of condom use were not significant, significant beta paths indicated that descriptive norm and expected friends’ approval predicted consistent condom use in the post-intervention period, whereas expected sex partner’s approval did not. Since sex partners are considerably more affected by the participants’ condom use than are his friends, this seems
123
counterintuitive. Moreover, it is in contrast to the RCT in the United States in which expected partner approval was one of the strongest mediators of intervention efficacy [4]. However, this finding may reflect the fact that condom-use decisions need be made only by men in South Africa, since they are the ones who apply them [28]. Thus, the approval of female partners may not be necessary for South African men to use condoms. In some cases, the intervention changed a mediator (alpha path) that was not related to the behavioral outcome (beta path). This raises the possibility that the intervention components in question may be superfluous, a possibility
AIDS Behav
future studies would have to address empirically. In the present study, this was the case with, for example, condomuse knowledge and prevention outcome expectancy. When the opposite happens, when a theoretical construct that is significantly related to behavior is not changed by the intervention, it may improve the intervention to add elements that can change the theoretical construct. This happened in one study [7] and explained the finding that the intervention did not change behavior. In the present study, the descriptive norm, the man’s belief that his closest friends were using condoms, although not changed by the intervention, was related to subsequent self-reported consistent condom use, which suggests that targeting the descriptive norm, perhaps by including men and their closest friends in the intervention, would be a way to enhance the efficacy of HIV risk-reduction interventions targeting South African men’s condom use. Mediation analysis provides information that can be used to streamline interventions, make them more costeffective, and suggest enhancements to address theoretical factors that predict behavior but were not affected by the intervention. However, interventions that have been thus improved should be re-tested because there may be significant interactions among mediators that have not been identified, in which case the revised intervention might not work. Whether this strategy is adopted or not, identifying mediators of effective interventions offers insights into the needs of different targeted populations and may eventually contribute to the development and refinement of theory and its implementation. This study is the first, to our knowledge, to identify significant mediators of an efficacious HIV/STD risk-reduction intervention for men. It targeted men in the middle of a generalized HIV epidemic, where heterosexual exposure is the main mode of HIV transmission and more than half of those infected are women [29]. However, it is not without limitations. We relied on self-report of sexual behavior, though the use of ACASI ameliorates concern about socially desirable responding somewhat. The reliability of the theoretical constructs ranged from 0.71 to 0.89. Higher reliability would have increased the statistical power for the mediation analyses; hence, we may have underestimated mediation. The study was conducted with isiXhosa-speaking men in Eastern Cape Province and might not generalize to all South African men. This rigorously implemented trial, with a randomized control design, high intervention attendance, and low attrition, lends additional support to the relevance of SCT to HIV prevention efforts, even outside the United States and other Western countries. South African men are an important target for interventions because they are responsible for condom use and protecting their female sexual partners and themselves. South Africa has a higher number
of HIV-infected people than any other country, and we hope that this intervention can be disseminated to reduce that number. Acknowledgments The authors wish to thank Craig Carty, Dr. Xoliswa Mtose, and Dr. Anita Heeren for their contributions to this study. The findings and conclusions are those of the authors and do not represent the views of the Centers for Disease Control and Prevention. This study was funded by a Research Grant 1 R01 HD053270 from the National Institutes of Health.
References 1. Baron RM, Kenny DA. The moderator-mediator variable distinction in social psychological research: conceptual, strategic, and statistical considerations. J Pers Soc Psychol. 1986;51(6): 1173–82. 2. MacKinnon DP, Lockwood CM, Hoffman JM, West SG, Sheets V. A comparison of methods to test mediation and other intervening variable effects. Psychol Methods. 2002;7(1):83–104. 3. Bandura A. Social foundations of thought and action: a social cognitive theory. Englewood Cliffs: Prentice-Hall; 1986. 4. National Institute of Mental Health Multisite HIV Prevention Trial Group. Social-cognitive theory mediators of behavior change in the National Institute of Mental Health Multisite HIV Prevention Trial. Health Psychol. 2001;20(5):369–76. 5. Sanderson CA, Jemmott JB 3rd. Moderation and mediation of HIV prevention interventions: relationship status, intentions, and condom use among college students. J Appl Soc Psychol. 1996;26:2076–99. 6. Fishbein M, Hennessy M, Kamb M, et al. Using intervention theory to model factors influencing behavior change. Project RESPECT. Eval Health Prof. 2001;24(4):363–84. 7. O’Leary A, Hoff CC, Purcell DW, et al. What happened in the SUMIT trial? Mediation and behavior change. AIDS. 2005;19(Suppl 1):S111–21. 8. O’Leary A, Jemmott LS, Jemmott JB 3rd. Mediation analysis of an effective sexual risk-reduction intervention for women: the importance of self-efficacy. Health Psychol. 2008;27(2 Suppl):S180–4. 9. O’Leary A, Jemmott JB 3rd, Jemmott LS, et al. Moderation and mediation of an effective HIV risk-reduction intervention for South African adolescents. Ann Behav Med. 2012;44(2):181–91. 10. Baumler E, Glassman J, Tortolero S, et al. Examination of the relationship between psychosocial mediators and intervention effects in It’s Your Game: an effective HIV/STI/pregnancy prevention intervention for middle school students. AIDS Res Treat. 2012;2012:298494. 11. Sales JM, Lang DL, DiClemente RJ, Latham TP, Wingood GM, Hardin JW, Rose ES. The mediating role of partner communication frequency on condom use among African American adolescent females participating in an HIV prevention intervention. Health Psychol. 2012;31(1):63–9. 12. Jemmott JB 3rd, Jemmott LS, O’Leary A, Ngwane Z, Icard LD, Heeren GA, Mtose X, Carty C. Cluster-randomized controlled trial of an HIV/STI risk-reduction intervention for South African men. Am J Public Health. 2014;104(3):467–73. 13. Jemmott JB 3rd, Jemmott LS, Ngwane Z, Zhang J, Heeren GA, Icard LD, O’Leary A, Mtose X, Teitelman A, Carty C. Theorybased behavioral intervention increases physical activity in South African men: a cluster-randomized controlled trial. Prev Med. 2014;. doi:10.1016/j.ypmed.2014.04.012. 14. O’Leary A, Wolitski RJ, Remien RH, Woods WJ, Parsons JT, Moss S, Lyles CM. Psychosocial correlates of transmission risk
123
AIDS Behav
15.
16.
17.
18.
19.
20. 21.
behavior among HIV-seropositive gay and bisexual men. AIDS. 2005;19(Suppl 1):S67–75. Jemmott JB 3rd, Jemmott LS, Fong GT. Abstinence and safer sex HIV risk-reduction interventions for African American adolescents: a randomized controlled trial. JAMA. 1998;279(19):1529–36. Jemmott JB 3rd, Jemmott LS, Fong GT, McCaffree K. Reducing HIV risk-associated sexual behavior among African American adolescents: testing the generality of intervention effects. Am J Commun Psychol. 1999;27(2):161–87. Jemmott JB 3rd, Jemmott LS, Braverman PK, Fong GT. HIV/STD risk reduction interventions for African American and Latino adolescent girls at an adolescent medicine clinic: a randomized controlled trial. Arch Pediatr Adolesc Med. 2005;159(5):440–9. Fishbein M, Ajzen I. Predicting and changing behavior: the reasoned action approach. New York: Taylor and Francis Group; 2010. Jemmott JB 3rd, Jemmott LS, Hacker CI. Predicting intentions to use condoms among African-American adolescents: the theory of planned behavior as a model of HIV risk-associated behavior. Ethn Dis. 1992;2(4):371–80. Ewing JA. Detecting alcoholism: the CAGE questionnaire. JAMA. 1984;252(14):1905–7. MacKinnon DP, Lockwood CM, Williams J. Confidence limits for the indirect effect: distribution of the product and resampling methods. Multivar Behav Res. 2004;39(1):99–128.
123
22. Fitzmaurice GM, Laird NM, Ware JH. Applied longitudinal analysis. New York: Wiley; 2004. 23. Liang KY, Zeger SL. Longitudinal data analysis using generalized linear models. Biometrika. 1986;73(1):13–22. 24. Preacher KJ, Rucker DD, Hayes AF. Addressing moderated mediation hypotheses: theory, methods, and prescriptions. Multivar Behav Res. 2007;42(1):185–227. 25. Jemmott JB 3rd, Jemmott LS, O’Leary A, Ngwane Z, Icard LD, Bellamy SL, Jones S, Landis JR, Heeron GA, Tyler J, Makiwane MB. School-based randomized controlled trial of an HIV/STD risk-reduction intervention for South African adolescents. Arch Pediatr Adolesc Med. 2010;164(10):923–9. 26. Jemmott LS, Jemmott JB 3rd, Ngwane Z, Icard LD, O’Leary A, Gueits L, Brawner B. ‘‘Let Us Protect Our Future!’’ A culturally congruent evidenced-based HIV/STD risk-reduction intervention for young South African adolescents. Health Educ Res. 2013;. doi:10.1093/her/cyt072. 27. Weinstein ND. Misleading tests of health behavior theories. Ann Behav Med. 2007;33(1):1–10. 28. O’Leary A. Preventing HIV infection in heterosexual women: what do we know? What do we need to learn? Appl Prev Psychol. 1999;8:257–63. 29. UNAIDS (2010) Global report: UNAIDS report on the global AIDS epidemic. http://www.unaids.org/globalreport/global_report.htm.
ORIGINAL PAPER
Mediation of an Efficacious HIV Risk Reduction Intervention for South African Men Ann O’Leary1 • John B. Jemmott III2 • Loretta S. Jemmott2 • Scarlett Bellamy2 Larry D. Icard3 • Zolani Ngwane4
•
Ó Springer Science+Business Media New York (outside the USA) 2015
Abstract ‘‘Men, Together Making a Difference!’’ is an HIV/STD risk-reduction intervention that significantly increased self-reported consistent condom use during vaginal intercourse compared with a health-promotion attentioncontrol intervention among men (N = 1181) in Eastern Cape Province, South Africa. The present analyses were designed to identify mediators of the intervention’s efficacy. The potential mediators were Social Cognitive Theory (SCT) constructs that the intervention targeted, including several aspects of condom-use self-efficacy, outcome expectancies, and knowledge. Mediation was assessed using a product-of-coefficients approach where an a path (the intervention’s effect on the potential mediator) and a b path (the potential mediator’s effect on the outcome of interest, adjusting for intervention) were estimated independently in a generalized estimating equations framework. Condom-use negotiation self-efficacy, technical-skill self-efficacy, and impulse-control self-efficacy were significant mediators. Although not mediators, descriptive norm and expected friends’ approval of condom use predicted subsequent self-reported condom use, whereas the expected approval of sexual partner did not. The present results suggest that HIV/STD risk-reduction interventions that draw upon SCT and that address self-efficacy to negotiate condom use, to apply condoms correctly, and to exercise sufficient control when sexually aroused to use & Ann O’Leary [email protected] 1
Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, 8 Corporate Square Blvd., Atlanta, GA 30329, USA
2
University of Pennsylvania, Philadelphia, PA, USA
3
Temple University, Philadelphia, PA, USA
4
Haverford College, Haverford, PA, USA
condoms may contribute to efforts to reduce sexual risk behavior among South African men. Future research must examine whether approaches that build normative support for condom use among men’s friends are also efficacious. Keywords HIV prevention Cluster-randomized trial South Africa Men Behavioral intervention Mediation
Introduction Many behavioral interventions contain multiple components, whose inclusion is often driven by the theoretical framework used to develop the interventions. Mediation analysis can reveal which components of an intervention were responsible for its effectiveness [1, 2]. In theory, the findings from a mediation analysis could be used to shorten the intervention to focus on only the efficacious components, potentially rendering the intervention more cost-effective. Several Social Cognitive Theory (SCT) [3] constructs, including self-evaluative outcome expectancy, hedonistic outcome expectancy, expected partner approval of condom use, and self-efficacy, mediated an intervention for low-income, urban patients from sexually transmitted disease (STD) clinics and primary care clinics [4]. Intention to use condoms mediated an HIV/STD risk-reduction intervention for college students [5], as well as one for STD clinic patients [6]. In a trial for HIV-infected gay and bisexual men, one factor that was not influenced by the intervention—personal responsibility to not infect others— was highly associated with behavior and behavior changes; this combination of results may explain why the intervention was not effective in reducing HIV transmission-risk behavior [7]. The effectiveness of an intervention for African American, inner-city women was mediated by expected partner reaction and condom-use self-efficacy in univariate analyses,
123
AIDS Behav
but only self-efficacy remained significant in a multivariate analysis [8]. In a trial with South African adolescents, the significant abstinence outcome was mediated by expected parental disapproval of the child being sexually active and self-efficacy to avoid sexual-risk situations [9]. Similarly, sex refusal self-efficacy as well as knowledge mediated an abstinence outcome for U.S. middle school students [10]. In another study of U.S. adolescents, frequency of communicating with male partners mediated an HIV risk-reduction intervention for adolescent girls [11]. ‘‘Men Together, Making a Difference’’ is an HIV/STD riskreduction intervention that was tested in a cluster-randomized controlled trial in Eastern Cape Province, South Africa [12]. Participants were South African men 18–45 years of age whose neighborhoods were randomized to receive either the HIV/STD risk-reduction intervention or a health promotion attention-control intervention. Each intervention, developed based on SCT integrated with extensive formative research with the population, consisted of three 2.5-h sessions of interactive exercises, games, brainstorming, role-playing, takehome assignments, group discussions, and videos implemented in small groups over a 3-week period. The primary outcome measure was self-reported consistent condom use. Accordingly, the HIV/STD risk-reduction intervention was designed to increase the men’s (a) self-efficacy, including the confidence that they could use condoms correctly, negotiate their use, and exercise sufficient control when sexually excited to use condoms; (b) outcome expectancies supporting condom use, including beliefs about the self-evaluative, hedonistic, and prevention consequences of using condoms; and (c) HIV/ STI risk-reduction knowledge. Data were collected at baseline, immediately post-, and 6 and 12 months post-intervention. More detailed descriptions of the interventions and methods can be found elsewhere [12, 13]. Generalized estimating equations (GEE) logistic regression analysis revealed that the HIV/STD risk-reduction intervention significantly increased self-reported consistent condom use averaged over 6- and 12-month follow-up assessments compared with the attention-control intervention, controlling for baseline consistent condom use and clustering of men within 44 neighborhoods [12]. In addition, the intervention’s efficacy in increasing condom use was not significantly different at the 6-month compared with 12-month follow-up. The present article reports analyses designed to identify which of several SCT constructs accounted for the efficacy of the intervention in increasing consistent condom use.
the study, more than 98 % of residents were Black Africans whose first language is isiXhosa. Assessment and intervention sessions were held at the University of Fort Hare in East London; transportation was provided to participants. Study protocols were approved by the Institutional Review Board (IRB) at the University of Pennsylvania, which was the designated IRB under the federal wide assurance of the University of Pennsylvania and the University of Fort Hare. We identified 206 neighborhoods defined as geographical clusters linked to census tracts, created matched pairs similar on the percentage isiXhosa-speaking, percentage married, percentage male, percentage unemployed, percentage living in informal dwellings, and population size, and randomly selected 22. One neighborhood within each pair was randomly assigned to either the HIV/STD risk-reduction intervention or to the health-promotion control intervention, which was of the same duration and format as the risk-reduction one. Support from the community leaders had been obtained prior to recruitment. Recruiters, who spoke isiXhosa, recruited men at different hours of the day and night, from a variety of venues. Men were eligible if they were aged 18–45, lived in one of the selected neighborhoods, had engaged in vaginal intercourse within the previous 90 days, and had a photo identification card or were willing to have their picture taken for identification purposes. Measures All measures were collected via audio computer-assisted self-interviewing (ACASI) on a laptop computer. The measures, which had been pilot-tested with 250 men, were available in isiXhosa (following translation and back translation from English), English, and a combination of isiXhosa (audio) and English (visual). Sexual Risk Behavior Outcome Consistent condom use during vaginal intercourse, the primary outcome for the study, was assessed by asking men who reported at least 1 vaginal intercourse act in the previous 90 days the number that were condom protected. If this number was equal to the total number of intercourse acts, the man was coded as practicing consistent condom use; if the reported number of condom-protected intercourse acts was less than his total number of intercourse acts, the man was coded as not practicing consistent condom use. Consistent condom use was assessed at baseline and 6 and 12 months following the interventions.
Methods Potential Mediators Methods for the study are described in detail elsewhere [12]. The study was conducted in Eastern Cape Province, South Africa from November 2007 to December 2010. In the area of
123
Table 1 presents the number of items, response format, and alphas for the potential mediators, all of which we have
AIDS Behav
employed in previous research. We assessed three types of outcome expectancy regarding condom use. Condom-use self-evaluative outcome expectancy is expected reactions of pride as a consequence of using condoms [4, 7, 14]. An example item from this scale is ‘‘I would feel good about myself if I used condoms.’’ Hedonistic condom-use outcome expectancy concerns the belief that sex is still pleasurable when condoms are used [4, 7, 8]. An example item is ‘‘If I used a condom, sex would feel as good.’’ Condomuse prevention outcome expectancy concerns the belief that condoms can prevent STDs, HIV, and pregnancy [15, 16]. An example of an item is ‘‘Condoms help prevent STDs.’’ We assessed four types of self-efficacy regarding condom use. Condom-use negotiation self-efficacy is the man’s belief that he can convince his partner to use condoms [5, 17]. An example of an item is ‘‘I can get my partner to use a condom, even if she doesn’t want to.’’ Condom-use technical skill self-efficacy is the man’s belief that he knows how to use condoms [8, 15, 17]. An example of an item is ‘‘I can use a condom, even if the room is dark.’’ Condom-use impulse control self-efficacy is the man’s belief that he can control himself sufficiently when sexually aroused to use a condom [15, 17]. An example item is ‘‘I can pause before sex in order to use a condom, even if I am already sexually aroused.’’ We also measured condom-use knowledge [8, 17]. An example of an item is ‘‘When a condom is put on the penis, a space should be left at the tip of the condom.’’ We assessed three theoretical variables that, though not targeted by the intervention, are constructs in our theoretical framework [3, 18]. Friends’ and sexual partners’ approval outcome expectancies were measured with two single items [17, 19]: ‘‘My friends would think it is okay
Table 1 Characteristics of theoretical constructs
for me to use a condom if I have sex in the next six months;’’ ‘‘My partner would think it is okay for me to use a condom if I have sex in the next six months.’’ Condomuse descriptive norm is the man’s belief regarding his closest friends’ use of condoms [18]. An example of an item is ‘‘How many of your 5 closest friends use condoms when they have vaginal intercourse.’’ Participants also completed measures of sociodemographic variables, the Cutting down, Annoyance by criticism, Guilty feeling, and Eye-openers (CAGE) questionnaire [20] which measures problem alcohol consumption, and measures of health-promotion behaviors and their potential mediators. Data Analysis We assessed mediation using a product-of-coefficients approach [2, 21] in which an a path denoted the effect of the intervention on the potential mediator at the immediate post-intervention assessment, a b path denoted the relation of the potential mediator to consistent condom use adjusted for the intervention, and the product of a and b (ab) quantifies the mediated effect of the intervention. The a paths were estimated in GEE models [22, 23] where the potential mediator was the outcome, with the intervention and the baseline of consistent condom use and the potential mediator as predictors. The b paths were estimated in GEE models with consistent condom use as the outcome and the intervention, potential mediator, time, and the baseline of consistent condom use and the potential mediator as predictors. We present two statistical evaluations of mediation, testing the null hypothesis that ab = 0 (i.e., no mediation): a Z statistic and corresponding p value [2] as
Construct
Number of items
Type of response
Alpha
Condom-use self-evaluative outcome expectancy
3
5-point Likert
0.76
Condom-use hedonistic outcome expectancy
6
5-point Likert
0.75
Condom-use prevention outcome expectancy
3
5-point Likert
0.82
Condom-use negotiation self-efficacy
5
5-point Likert
0.89
Condom-use technical skill self-efficacy
7
5-point Likert
0.89
Condom-use impulse control self-efficacy
3
5-point Likert
0.74
Condom-use knowledge
4
True/False
–
Condom-use descriptive norm
3
4-point Likert
0.75
Condom-use expected friends’ approval
1
5-point Likert
–
Condom-use expected partners’ approval
1
5-point Likert
–
Condom-use expected normative approval
2
5-point Likert
0.71
Ratings on the Likert scales could range from 1 (Disagree strongly) to 5 (Agree strongly) except for condom-use descriptive norm where the ratings could range from 1 (None of them) to 4 (All of them). The score was the mean of the ratings except for condom-use knowledge where the score was the sum of the number of items correctly answered. Alpha is Cronbach’s coefficient alpha for the post-intervention assessment of the construct, which was analyzed as the potential mediator
123
AIDS Behav
well as asymmetric confidence limits (ACL) for ab that accommodate the non-normal distribution of a product statistic [21]. All models were fit using a GEE approach, adjusting for the potential mediator and self-reported consistent condom use at baseline, the longitudinal correlation of measuring outcomes repeatedly over time, and clustering of men within 44 neighborhoods. We also performed moderated-mediation analyses testing whether the follow-up time affected the a paths (intervention 9 follow-up time interactions) or the b paths (potential mediator 9 follow-up time interactions) for each potential mediator. Here a significant interaction would indicate that the mediation of the intervention’s efficacy was different at the 6-month follow-up compared with the 12-month follow-up [24]. All hypotheses were tested using the two-sided, alpha = 0.05 significance criterion, and all were performed using SAS Version 9.
Results Sociodemographic characteristics, by intervention arm and overall, are given in Table 2. A total of 1181 men (mean age = 26.7 years; SD = 6.6) enrolled in the trial. Virtually all spoke isiXhosa as their home language. Few were married, but 80 % had a steady partner in the prior 3 months. Majorities of men were unemployed, had not completed high school, and were alcohol-dependent. Attendance at the intervention sessions was high: 1181 (100 %), 1171 (99.2 %), and 1165 (98.6 %) attended intervention sessions 1, 2, and 3, respectively. Retention at the follow-ups was excellent: 1140 or 96.5 % attended at least one of the two follow-up assessments, including 1093 (92.5 %) who attended the 6-month follow-up and 1106 (93.6 %) who attended the 12-month follow-up. The percentage attending at least one follow-up session did not differ in the HIV/STI risk-reduction intervention compared with the health-promotion control intervention or by baseline age group, high school education, unemployment, marital status, steady or casual partners, alcohol problems, or self-reported consistent condom use. Table 3 presents potential mediator and outcome summaries, by intervention, at each assessment point (i.e., baseline and 6 and 12 months post–intervention). Means and standard errors are presented for each potential mediator and the number and percentage of men reporting consistent condom use in the past 3 months. Table 4 displays the mediation results, including the estimated ICC for the ‘alpha’ path in the model. Specifically, this ICC was estimated treating the longitudinal mediator as the outcome in a model that included intervention, time and cluster (neighborhood). Results were the same using the Z test and the ACL approach, where mediation is indicated when the ACL does not contain
123
zero. As can be seen from the table, several of the selfefficacy variables were significant mediators of the intervention effect. Self-efficacy for condom negotiation, selfefficacy for technical skills in condom application, and self-efficacy for impulse control were all significant mediators. As the significant a paths indicate, the HIV/STD risk-reduction intervention increased each of these constructs compared with the health promotion attention-control intervention. Significant b paths indicate that increases in these constructs predicted higher odds of self-reported consistent condom use. In contrast, the outcome expectancies regarding condom use, including self-evaluative, hedonistic expectancies, and prevention outcome expectancy were not significant mediators; neither were availability self-efficacy, expected friends’ approval of condom use, expected partners’ approval, descriptive norm (the belief that one’s closest friends use condoms), or condom-use knowledge. Although the a paths were significant for all eight of these variables except descriptive norm, the b paths were significant for only two of them: descriptive norm and expected friends’ approval of condom use. There was no evidence that follow-up time moderated the alpha path or the beta path; therefore, the mediation of the intervention’s efficacy was not significantly different at the 6-month follow-up compared with the 12-month follow-up.
Discussion The present results indicate that SCT, a theory developed in the United States, is applicable and valuable even in distant cultures. Our previous work with South African adolescents established this as well [9, 25, 26]. In fact, mediation analysis of interventions’ efficacy is a particularly useful way to substantiate the relevance of theory to behavior [27]. The SCT mediators we identified here were instantiated in the intervention through interactive activities and skill-building activities to build self-efficacy. Significant mediators included self-efficacy to negotiate condom use, self-efficacy for condom-use technical skills, and self-efficacy for condom-use impulse control. Prevention expectancies, which are based on simple information regarding the effects of condoms on preventing pregnancy and STD, were not significant mediators. Relatedly, condom-use knowledge was not a significant mediator. In both cases, the alpha paths were significant, indicating that the intervention had the expected effects on the variables. However, the beta paths were not significant, indicating the variables did not predict increased condom use. The results for both of these theoretical constructs are consonant with the notion that information alone is not sufficient to change behavior [17].
AIDS Behav Table 2 Sociodemographic characteristics of neighborhoods and participating men by intervention condition at baseline, Eastern Cape Province, South Africa 2007–2010 Characteristic
HIV/STD Intervention
Health Control Intervention
Total
No. (%) isiXhosa home language
607/609 (99.7 %)
571/572 (99.8 %)
1178/1181 (99.8 %)
No. (%) married No. (%) steady partner in past 3 months
27/609 (4.4 %)
41/572 (7.2 %)
68/1181 (5.8 %)
494/609 (81.1 %)
451/572 (78.8 %)
945/1181 (80.0 %)
No. (%) casual partner in past 3 months
328/609 (53.9 %)
274/572 (47.9 %)
602/1181 (51.1 %)
No. (%) unemployed
425/609 (69.8 %)
368/572 (64.3 %)
793/1181 (67.1 %)
279/609 (45.8 %)
239/572 (41.8 %)
518/1181 (43.9 %)
377/609 (61.9 %)
330/572 (57.7 %)
707/1181 (59.9 %)
18–24
282/609 (46.3) %
273/572 (47.7 %)
555/1181 (47.0 %)
25–29
158/609 (25.9 %)
126/572 (22.0 %)
284/1181 (24.0 %)
30–45
169/609 (27.8 %)
173/572 (30.2 %)
342/1181 (29.0 %)
Own house or flat
115/609 (18.8) %
107/572 (18.7 %)
222/1181 (18.8 %)
Family’s house
369/609 (60.6 %)
361/572 (63.1 %)
730/1181 (61.8 %)
Partner’s house
19/609 (3.1) %
13/572 (2.3 %)
32/1181 (2.7 %)
Rented room
15/609 (2.5 %)
12/572 (2.1 %)
27/1181 (2.3 %)
Shack in someone else’s yard
91/609 (14.9 %)
79/572 (13.8 %)
170/1181 (14.3 %)
No. (%) completed high school No. (%) alcohol dependent No. (%) age (years) group
a
No. (%) housing circumstances
a
Based on a score of 2 or greater on the Cutting down, Annoyance by criticism, Guilty feeling, and Eye-openers (CAGE) questionnaire
Table 3 Potential mediator and outcome summaries at study time points for HIV/STD risk reduction (RR) and health promotion (HP) interventions Potential mediators (mean ± SE)
Baseline HP
RR
Immediate post
6-month
HP
HP
RR
12-month RR
HP
RR
Condom-use knowledge
3.09 ± 0.04
3.10 ± 0.03
3.16 ± 0.04
3.57 ± 0.03
3.05 ± 0.04
3.38 ± 0.03
3.12 ± 0.04
3.37 ± 0.04
Self-evaluative expectancy
4.04 ± 3.89
4.00 ± 0.03
4.13 ± 0.03
4.32 ± 0.02
4.10 ± 0.03
4.25 ± 0.03
4.03 ± 0.04
4.26 ± 0.03
Hedonistic expectancy
3.37 ± 0.03
3.35 ± 0.03
3.59 ± 0.03
4.06 ± 0.03
3.62 ± 0.03
3.90 ± 0.03
3.68 ± 0.03
3.93 ± 0.03
Prevention expectancy
4.38 ± 0.03
4.34 ± 0.03
4.30 ± 0.03
4.43 ± 0.03
4.36 ± 0.03
4.37 ± 0.03
4.23 ± 0.04
4.35 ± 0.03 2.77 ± 0.04
Descriptive norm
2.70 ± 0.04
2.75 ± 0.04
2.68 ± 0.04
2.82 ± 0.04
2.68 ± 0.04
2.83 ± 0.04
2.68 ± 0.04
Expected friend approval
4.05 ± 0.04
4.15 ± 0.04
4.01 ± 0.05
4.08 ± 0.04
3.89 ± 0.05
3.99 ± 0.05
3.74 ± 0.06
3.94 ± 0.05
Expected partner approval Available self-efficacy
3.98 ± 0.05 4.01 ± 0.03
4.05 ± 0.04 3.99 ± 0.03
4.07 ± 0.04 4.08 ± 0.03
4.11 ± 0.04 4.16 ± 0.02
3.88 ± 0.05 4.13 ± 0.03
4.05 ± 0.05 4.16 ± 0.02
3.87 ± 0.05 4.11 ± 0.03
4.01 ± 0.04 4.15 ± 0.03
Negotiation self-efficacy
4.04 ± 0.03
4.05 ± 0.03
4.11 ± 0.03
4.27 ± 0.02
4.10 ± 0.03
4.24 ± 0.02
4.06 ± 0.03
4.26 ± 0.02
Technical skill selfefficacy
3.86 ± 0.03
3.80 ± 0.03
3.95 ± 0.03
4.12 ± 0.02
3.95 ± 0.03
4.10 ± 0.03
3.98 ± 0.03
4.16 ± 0.03
Impulse control selfefficacy
3.46 ± 0.04
3.45 ± 0.04
3.66 ± 0.02
3.96 ± 0.03
3.63 ± 0.04
3.91 ± 0.03
3.68 ± 0.04
3.95 ± 0.03
211 (36.89)
248 (40.72)
211 (36.89)
248 (40.72)
182 (31.82)
216 (35.47)
177 (30.94)
207 (33.99)
Outcome N (%) Consistent condom use
Although increased by the intervention, hedonistic outcome expectancies and self-evaluative outcome expectancies also were not significant mediators as they did not
significantly predict consistent condom use. This is in contrast to a RCT in the United States reporting that hedonistic outcome expectancies and self-evaluative outcome
123
AIDS Behav Table 4 GEE mediation analysis of intervention effects (HIV/STD intervention versus health promotion intervention) fit to ‘consistent (100 %) condom use’ with causal and main partners (at 6- and 12-month follow-up) Potential mediator
ICC (a path)
a path ± SE (p value)a
b path ± SE (p value)b
Product ab (p value) [ACL]c
Condom-use knowledge
0.02
0.336 ± 0.040
-0.114 ± 0.150
-0.038
(\0.001)
(0.448)
(0.449)
0.175 ± 0.042
0.216 ± 0.156
0.038
(\0.001)
(0.166)
(0.188)
[-0.138, 0.061] Self-evaluative expectancy
0.02
[-0.019, 0.094] Hedonistic expectancy
0.02
0.391 ± 0.044 (\0.001)
0.252 ± 0.161 (0.119)
0.098 (0.124)
Prevention expectancy
0.01
0.139 ± 0.035
0.088 ± 0.129
0.012
(\0.001)
(0.494)
(0.501)
0.084 ± 0.052
0.370 ± 0.111
0.031
(0.102)
(0.001)
(0.142)
0.160 ± 0.071
0.200 ± 0.088
0.032
(0.024)
(0.023)
(0.108)
0.163 ± 0.065
0.203 ± 0.112
0.033
(0.013)
(0.070)
(0.144)
[-0.0027, 0.224]
[-0.024, 0.048] Descriptive norm
0.01
[-0.011, 0.073] Expected friends’ approval
0.01
[-0.007, 0.071] Available self-efficacy
0.01
[-0.011, 0.077] Expected partners’ approval
0.03
0.063 ± 0.030 (0.037)
0.043 ± 0.210 (0.836)
0.003 (0.837)
Negotiation self-efficacy
0.02
0.150 ± 0.037
0.455 ± 0.163
0.068
(\0.001)
(0.005)
(0.021)
[-0.023, 0.029]
[0.010, 0.127] Technical skill self-efficacy
0.02
0.175 ± 0.039
0.478 ± 0.194
0.083
(\0.001)
(0.014)
(0.031)
0.347 ± 0.051
0.348 ± 0.098
0.121
(\0.001)
(\0.001)
(0.002)
[0.007, 0.159] Impulse control self-efficacy
0.01
[0.045, 0.196]
expectancies mediated the effects of an HIV risk reduction intervention on condom use among urban low-income African American men and women [4]. While the indirect effects of the intervention through descriptive norm, expected friends’ approval of condom use, and expected sex partners’ approval of condom use were not significant, significant beta paths indicated that descriptive norm and expected friends’ approval predicted consistent condom use in the post-intervention period, whereas expected sex partner’s approval did not. Since sex partners are considerably more affected by the participants’ condom use than are his friends, this seems
123
counterintuitive. Moreover, it is in contrast to the RCT in the United States in which expected partner approval was one of the strongest mediators of intervention efficacy [4]. However, this finding may reflect the fact that condom-use decisions need be made only by men in South Africa, since they are the ones who apply them [28]. Thus, the approval of female partners may not be necessary for South African men to use condoms. In some cases, the intervention changed a mediator (alpha path) that was not related to the behavioral outcome (beta path). This raises the possibility that the intervention components in question may be superfluous, a possibility
AIDS Behav
future studies would have to address empirically. In the present study, this was the case with, for example, condomuse knowledge and prevention outcome expectancy. When the opposite happens, when a theoretical construct that is significantly related to behavior is not changed by the intervention, it may improve the intervention to add elements that can change the theoretical construct. This happened in one study [7] and explained the finding that the intervention did not change behavior. In the present study, the descriptive norm, the man’s belief that his closest friends were using condoms, although not changed by the intervention, was related to subsequent self-reported consistent condom use, which suggests that targeting the descriptive norm, perhaps by including men and their closest friends in the intervention, would be a way to enhance the efficacy of HIV risk-reduction interventions targeting South African men’s condom use. Mediation analysis provides information that can be used to streamline interventions, make them more costeffective, and suggest enhancements to address theoretical factors that predict behavior but were not affected by the intervention. However, interventions that have been thus improved should be re-tested because there may be significant interactions among mediators that have not been identified, in which case the revised intervention might not work. Whether this strategy is adopted or not, identifying mediators of effective interventions offers insights into the needs of different targeted populations and may eventually contribute to the development and refinement of theory and its implementation. This study is the first, to our knowledge, to identify significant mediators of an efficacious HIV/STD risk-reduction intervention for men. It targeted men in the middle of a generalized HIV epidemic, where heterosexual exposure is the main mode of HIV transmission and more than half of those infected are women [29]. However, it is not without limitations. We relied on self-report of sexual behavior, though the use of ACASI ameliorates concern about socially desirable responding somewhat. The reliability of the theoretical constructs ranged from 0.71 to 0.89. Higher reliability would have increased the statistical power for the mediation analyses; hence, we may have underestimated mediation. The study was conducted with isiXhosa-speaking men in Eastern Cape Province and might not generalize to all South African men. This rigorously implemented trial, with a randomized control design, high intervention attendance, and low attrition, lends additional support to the relevance of SCT to HIV prevention efforts, even outside the United States and other Western countries. South African men are an important target for interventions because they are responsible for condom use and protecting their female sexual partners and themselves. South Africa has a higher number
of HIV-infected people than any other country, and we hope that this intervention can be disseminated to reduce that number. Acknowledgments The authors wish to thank Craig Carty, Dr. Xoliswa Mtose, and Dr. Anita Heeren for their contributions to this study. The findings and conclusions are those of the authors and do not represent the views of the Centers for Disease Control and Prevention. This study was funded by a Research Grant 1 R01 HD053270 from the National Institutes of Health.
References 1. Baron RM, Kenny DA. The moderator-mediator variable distinction in social psychological research: conceptual, strategic, and statistical considerations. J Pers Soc Psychol. 1986;51(6): 1173–82. 2. MacKinnon DP, Lockwood CM, Hoffman JM, West SG, Sheets V. A comparison of methods to test mediation and other intervening variable effects. Psychol Methods. 2002;7(1):83–104. 3. Bandura A. Social foundations of thought and action: a social cognitive theory. Englewood Cliffs: Prentice-Hall; 1986. 4. National Institute of Mental Health Multisite HIV Prevention Trial Group. Social-cognitive theory mediators of behavior change in the National Institute of Mental Health Multisite HIV Prevention Trial. Health Psychol. 2001;20(5):369–76. 5. Sanderson CA, Jemmott JB 3rd. Moderation and mediation of HIV prevention interventions: relationship status, intentions, and condom use among college students. J Appl Soc Psychol. 1996;26:2076–99. 6. Fishbein M, Hennessy M, Kamb M, et al. Using intervention theory to model factors influencing behavior change. Project RESPECT. Eval Health Prof. 2001;24(4):363–84. 7. O’Leary A, Hoff CC, Purcell DW, et al. What happened in the SUMIT trial? Mediation and behavior change. AIDS. 2005;19(Suppl 1):S111–21. 8. O’Leary A, Jemmott LS, Jemmott JB 3rd. Mediation analysis of an effective sexual risk-reduction intervention for women: the importance of self-efficacy. Health Psychol. 2008;27(2 Suppl):S180–4. 9. O’Leary A, Jemmott JB 3rd, Jemmott LS, et al. Moderation and mediation of an effective HIV risk-reduction intervention for South African adolescents. Ann Behav Med. 2012;44(2):181–91. 10. Baumler E, Glassman J, Tortolero S, et al. Examination of the relationship between psychosocial mediators and intervention effects in It’s Your Game: an effective HIV/STI/pregnancy prevention intervention for middle school students. AIDS Res Treat. 2012;2012:298494. 11. Sales JM, Lang DL, DiClemente RJ, Latham TP, Wingood GM, Hardin JW, Rose ES. The mediating role of partner communication frequency on condom use among African American adolescent females participating in an HIV prevention intervention. Health Psychol. 2012;31(1):63–9. 12. Jemmott JB 3rd, Jemmott LS, O’Leary A, Ngwane Z, Icard LD, Heeren GA, Mtose X, Carty C. Cluster-randomized controlled trial of an HIV/STI risk-reduction intervention for South African men. Am J Public Health. 2014;104(3):467–73. 13. Jemmott JB 3rd, Jemmott LS, Ngwane Z, Zhang J, Heeren GA, Icard LD, O’Leary A, Mtose X, Teitelman A, Carty C. Theorybased behavioral intervention increases physical activity in South African men: a cluster-randomized controlled trial. Prev Med. 2014;. doi:10.1016/j.ypmed.2014.04.012. 14. O’Leary A, Wolitski RJ, Remien RH, Woods WJ, Parsons JT, Moss S, Lyles CM. Psychosocial correlates of transmission risk
123
AIDS Behav
15.
16.
17.
18.
19.
20. 21.
behavior among HIV-seropositive gay and bisexual men. AIDS. 2005;19(Suppl 1):S67–75. Jemmott JB 3rd, Jemmott LS, Fong GT. Abstinence and safer sex HIV risk-reduction interventions for African American adolescents: a randomized controlled trial. JAMA. 1998;279(19):1529–36. Jemmott JB 3rd, Jemmott LS, Fong GT, McCaffree K. Reducing HIV risk-associated sexual behavior among African American adolescents: testing the generality of intervention effects. Am J Commun Psychol. 1999;27(2):161–87. Jemmott JB 3rd, Jemmott LS, Braverman PK, Fong GT. HIV/STD risk reduction interventions for African American and Latino adolescent girls at an adolescent medicine clinic: a randomized controlled trial. Arch Pediatr Adolesc Med. 2005;159(5):440–9. Fishbein M, Ajzen I. Predicting and changing behavior: the reasoned action approach. New York: Taylor and Francis Group; 2010. Jemmott JB 3rd, Jemmott LS, Hacker CI. Predicting intentions to use condoms among African-American adolescents: the theory of planned behavior as a model of HIV risk-associated behavior. Ethn Dis. 1992;2(4):371–80. Ewing JA. Detecting alcoholism: the CAGE questionnaire. JAMA. 1984;252(14):1905–7. MacKinnon DP, Lockwood CM, Williams J. Confidence limits for the indirect effect: distribution of the product and resampling methods. Multivar Behav Res. 2004;39(1):99–128.
123
22. Fitzmaurice GM, Laird NM, Ware JH. Applied longitudinal analysis. New York: Wiley; 2004. 23. Liang KY, Zeger SL. Longitudinal data analysis using generalized linear models. Biometrika. 1986;73(1):13–22. 24. Preacher KJ, Rucker DD, Hayes AF. Addressing moderated mediation hypotheses: theory, methods, and prescriptions. Multivar Behav Res. 2007;42(1):185–227. 25. Jemmott JB 3rd, Jemmott LS, O’Leary A, Ngwane Z, Icard LD, Bellamy SL, Jones S, Landis JR, Heeron GA, Tyler J, Makiwane MB. School-based randomized controlled trial of an HIV/STD risk-reduction intervention for South African adolescents. Arch Pediatr Adolesc Med. 2010;164(10):923–9. 26. Jemmott LS, Jemmott JB 3rd, Ngwane Z, Icard LD, O’Leary A, Gueits L, Brawner B. ‘‘Let Us Protect Our Future!’’ A culturally congruent evidenced-based HIV/STD risk-reduction intervention for young South African adolescents. Health Educ Res. 2013;. doi:10.1093/her/cyt072. 27. Weinstein ND. Misleading tests of health behavior theories. Ann Behav Med. 2007;33(1):1–10. 28. O’Leary A. Preventing HIV infection in heterosexual women: what do we know? What do we need to learn? Appl Prev Psychol. 1999;8:257–63. 29. UNAIDS (2010) Global report: UNAIDS report on the global AIDS epidemic. http://www.unaids.org/globalreport/global_report.htm.
