Study Design and Study Subjects
The study was conducted from 2002 to 2007 in beer halls located in low-income, residential neighborhoods of Harare, Zimbabwe. There were 56 beer halls located in the city of Harare in 2002. We chose 43 in which to conduct a preliminary or pre-baseline survey followed 1 year later by a baseline or pre-intervention survey. Three of the venues closed after the pre-baseline survey and thus were not included in the baseline survey. Inclusion criteria for beer halls were being located in a residential area and not adjacent to large markets or public transport hubs that could contribute to cross-contamination between beer halls after randomization. At pre-baseline and baseline, we collected information on men’s beer hall attendance patterns, including patronage of multiple venues. Based on these data, we selected 24 of the initially surveyed 40 beer halls with the least amount of cross-patronage and randomly assigned them to 12 intervention and 12 control or comparison conditions using a random numbers table.
Pre-Baseline and Baseline Survey Procedures and Measures
We completed a pre-baseline seroprevalence and behavior survey in 2003 and repeated the survey in 2004. These surveys assessed time trends in HIV prevalence and risk behavior in advance of the intervention, determined comparability and stability of baseline characteristics over time, and explored potential for cross-contamination between beer halls after randomization. To obtain a representative sample of male beer hall patrons for the surveys, we adapted time-location sampling (TLS), a spatial–temporal method developed for recruitment of subjects attending drinking establishments and other diverse venues [37–39]. The method entailed (1) constructing a comprehensive sampling frame, in this case the beer halls chosen for inclusion; (2) creating a calendar of 4-h recruitment events; (3) randomly selecting beer halls to fill each calendar event; and (4) assessing the eligibility of every third man entering an intercept zone located at the beer hall entrance. The spatial–temporal sampling frame was constructed such that 70% of recruitment events took place during peak patronage periods (Friday evenings, Saturdays and Sundays) and 30% during slow to moderate periods (weekday evenings). Eligibility criteria were being male, 18 years of age and older, a patron of the beer hall where recruited, sober, and being enumerated as one of every three people to cross the predetermined intercept zone at the entrance of the beer hall during the sampling period after a randomly chosen starting time. Eligible participants provided written informed consent, completed an interviewer-administered behavioral questionnaire, underwent HIV pre-test counseling, and had blood drawn for HIV testing. Informed consent, interview, blood draw, and counseling procedures took place in a mobile van parked near the beer hall entrance. Blood samples were screened for HIV antibody by HIV ½ gO enzyme immunoassay (EIA) (Abbott Laboratories, Abbott Park, IL) and confirmed by a Dipstick rapid HIV assay (Pacific Biotech Co., Ltd., Bangkok, Thailand). Indeterminate results were resolved using Biotest EIA (Biotest Diagnostics Corp., Denville, NJ). At the time of the blood draw and pre-test counseling, participants were encouraged, but not required, to make an appointment to receive their HIV test results. Test results, post-test counseling, and referral to post-test care and support services were provided by our study staff.
Behavioral measures, including the primary outcome and several indicators of HIV-related risk, were collected through an interviewer administered, standardized questionnaire. The questionnaire included demographic characteristics, patterns of beer hall attendance and alcohol use, partner-by-partner sexual behavior in the previous 6 months, self-reported STI symptoms, patterns of peer influence on sexual risk behavior, knowledge about HIV, and previous exposure to HIV prevention materials or activities at the bars. Details of the measures, development, validation, and previous applications of the instrument have been published previously [17, 32]. The questionnaire was co-developed in Shona and English, forward and backward translated, field tested, and revised incorporating feedback from the current and previous studies of the target population [17, 32]. For sexual risk behavior measures, the approach was to collect information on each individual sexual partner for up to seven partners in the preceding 6 months. Each partner was self-described by type and classified into the categories of wife (including multiple wives in polygamous marriages and common law and formal wives according to civil, religious, and customary criteria), steady partner (by self-description), casual partner (not wives or steady partners but with whom sex occurred more than once), one off partners (with whom sex was only one time, but with whom no cash for sex was exchanged), and commercial partners (with whom cash was given for sex). For each partner, we elicited counts of the episodes of sexual contact and condom use with each episode over the last 6 months, and whether condoms were used at the last episode of unprotected sex while intoxicated. We examined sexual risk behavior by each partner type separately, by combining all partner types, and by combining all non-wife partner types. We also classified men as having no sex with any partners in the last 6 months and married and having no other partners. An 8-point factual knowledge score was also collected composed of recognizing modes of transmission, means of preventing HIV, and dispelling common myths about HIV. We also recorded whether men had previously tested for HIV.
Following the baseline survey, 24 beer halls were selected based on their low levels of cross-patronage. Twelve were randomly assigned to the intervention condition and twelve to the comparison condition.
Comparison Condition Procedures
Beer halls in the comparison arm of the study received a basic package of HIV prevention materials consistent with what was available in Zimbabwe at the time the study intervention took place. This included a steady supply of condoms for sale behind the bar and condom advertisements within the beer hall. We also displayed HIV prevention posters developed by the National AIDS Control Programme, ensuring that none of the posters portrayed prevention themes or slogans similar to those of the intervention.
Intervention Condition Procedures
Intervention beer halls received the same basic package of intervention materials and services as comparison beer halls. In addition, we implemented the elements of The Sahwira HIV Prevention Program. The intervention focused on a cadre of 413 male beer hall patrons who volunteered to become Sahwira peer educators. To recruit peer educators, study staff circulated at the beer halls distributing promotional brochures and talking to patrons about the Sahwira HIV Prevention Program. To further promote the theme of friends assisting each other to reduce HIV risk behavior, peer educators were recruited as dyads—pairs of friends who regularly attended the beer hall together. The criteria for becoming a peer educator were being 18 years or older, volunteering along with a good friend who was also at least 18 years old and a patron of the same beer hall, attending the beer hall at least eight times per month, being available to complete the three-day training and subsequently volunteer for a 15-month period. Because the recruitment process resulted in an over-enrollment of interested beer hall patrons, names were entered into a lottery and a public drawing was held at each beer hall as part of an HIV awareness event. Individuals chosen in the public drawing were invited to attend the training.
Peer educators received a three-day intensive training and 26 follow-up support meetings at their beer halls over a 15-month period. The three-day training curriculum included 14 sessions. Each session addressed one or more elements of the Information-Motivation-Behavioral Skills (IMB) behavior change theory [40, 41]. Subsequent support sessions were guided by a curriculum that further elaborated on material introduced in the initial training. The training and follow-up support of Sahwira peer educators was provided by eight full-time study staff members. The number of Sahwira educators recruited and trained was guided by the Diffusion of Innovation Theory [42, 43]. We determined the number of Sahwira educators to enroll by counting the number of men attending beer halls at peak attendance periods over a 1 month period, averaging the figures, and calculating how many peer educators would represent 20% of the peak patronage at each beer hall. We then adjusted the number upward by a relative 40% (8% absolute) in order to compensate for expected attrition over the course of the 15-month intervention period. Sahwira peer educators received no monetary compensation for their effort; however, we did provide each educator with non-monetary incentives including certificates, a bag and cap printed with the intervention name and logo, and career development workshops.
Sahwira peer educator activities in beer halls included facilitating one-on-one and small-group discussions to promote HIV knowledge and risk reduction, organizing beer hall-wide awareness events, disseminating the Sahwira peer support theme by teaching beer hall patrons how to intervene with their friends when they saw a high risk situation unfolding, disseminating accurate information about condoms, providing demonstrations of correct condom use, and assisting beer hall managers to maintain an adequate supply of condoms for sale.
One Year Follow-Up Assessment of Risk Behavior
At the close of the 15-month intervention, we conducted a post-intervention assessment survey using the same methods and measures as the pre-baseline and baseline surveys; however, we added survey questions on intervention exposure, including awareness of the intervention theme, recognition of the intervention logo, recall of intervention messages, number of peer educators known to the patron, and exposure to intervention activities such as condom demonstrations, small group or one-on-one discussions, or special events. We also included questions about exposure to false materials or activities in order to assess levels of acquiescence bias.
The analysis approach uses the beer hall as the unit of statistical power and evaluation because the unit of randomization was the beer hall, the intervention was delivered at the level of the beer hall, and the point for determining impact of the intervention was the patronage of the beer hall. Therefore the effective N was 24 (i.e., 12 intervention vs. 12 control beer halls). Data were recorded at the individual level; however, for each variable, we examined percentages (e.g., percent currently married), medians, and means (e.g., age, number of partners, episodes of unprotected sex with non-spouse partners) for the patrons of each beer hall. Thus, each variable had 24 values corresponding to the levels at each beer hall. Comparisons of the percentages or median values between the intervention and control beer halls (12 vs. 12) were made using the non-parametric Wilcoxon rank sum test.
We first assessed whether there were significant differences between intervention and control beer halls at baseline. These included demographic characteristics, alcohol dependency (CAGE score), and HIV-risk related behaviors. In the post-intervention assessment, we assessed the reach, intensity, and impact of the intervention activities between the intervention and control beer halls. Our primary a priori hypothesis for the impact of the intervention, and the basis of our sample size and power estimation, was that the intervention could achieve a 40% lower number of episodes of unprotected sex with non-wife partners in the last 6 months among intervention beer hall patrons compared to control. Secondary outcomes included number of unprotected sexual episodes with specific partner types (including steady, casual, one off, and commercial sex partners), numbers of these different partner types, unprotected sex while intoxicated at last episode of sex with each partner type, abstaining from any sex, being faithful to one’s wife (among married men), HIV/AIDS knowledge, and testing for HIV.
Additional analyses were done to explore for further evidence of an intervention effect. We assessed whether there were significant changes in risk behaviors from pre- to post-intervention waves in each of the two study arms by subtracting the post-intervention level from the pre-intervention level for each beer hall and applying the sign rank test. We assessed whether certain prevention activities were associated with risk reduction in the intervention arm by conducting Pearson correlations between the levels of specific activities at the beer hall and the level of reported risk behaviors. Finally, we assessed the potential effect of alcohol dependency on the intervention’s impact on risk behavior by stratifying three levels of CAGE scores (terciles of high, medium, low). All analyses were done using the SAS statistical package (SAS version 8.0; Cary, NC, USA).