Assessing the Impact of an Intervention to Prevent Intimate Partner Violence and HIV in Uganda
Condition: HIV; Physical Abuse of Adult (If Focus of Attention is on Victim); Sexual Abuse of Adult (If Focus of Attention is on Victim); Risk Reduction Behavior
Study type: Interventional

Summary: 
      Intimate partner violence (IPV) is a precursor to and consequence of HIV infection. Few
      interventions combining HIV and IPV prevention have been evaluated and none has significantly
      decreased both outcomes.

      A cluster-randomized trial was conducted in Rakai, Uganda. Four intervention arm clusters
      (N=5,339) received an IPV prevention intervention (the Safe Homes and Respect for Everyone
      (SHARE) Project), enhanced HIV testing and treatment and routine HIV services provided by
      Rakai Health Sciences Program (RHSP). Seven control arm clusters (N=6,112) received standard
      of care HIV services alone.

      Baseline and two follow-up visits were conducted via the Rakai Community Cohort Study between
      2005 and 2009. Primary outcomes were past year emotional, physical and sexual IPV and HIV
      incidence. Secondary outcomes included past year intimate partner rape/forced sex, number of
      total and extra-marital sex partners, alcohol use surrounding sex, condom use, discussion
      about condom use, partner's disclosure of HIV status and respondent's disclosure of HIV
      status. Analysis was by intention-to-treat. Modified Poisson regression was used to estimate
      prevalence risk ratios (PRR) to detect the impact of the intervention on IPV and secondary
      outcomes. Poisson regression was used to estimate incidence rate ratios (IRR) of HIV
      acquisition per 100 person years (py).

      Our study had three research aims and related hypotheses.

      Aim 1 was to assess the impact of SHARE + RHSP community services on report of victimization
      from and perpetration of physical and/or sexual IPV in the past 12 months, compared to the
      impact of RHSP community services alone.

      Hypothesis 1(a): SHARE intervention will reduce women's reports of IPV victimization in
      intervention vs. control arms.

      Hypothesis 1(b): SHARE intervention will reduce men's reports of IPV perpetration in
      intervention vs. control arms.

      Aim 2 was to assess the impact of SHARE + RHSP services on report of sexual risk behaviors
      among men and women compared to the impact of RHSP community services alone.

      Hypothesis 2(a): SHARE intervention will reduce selected sexual risk behaviors in the
      intervention vs. control arms.

      Aim 3 was to assess the impact of SHARE + RHSP services on HIV incidence compared to the
      impact of RHSP community services alone.

      Hypothesis 3(a): Incidence of HIV will be lower in the intervention vs. control arms.
    

Detailed description: 
      Research Team: Rakai Health Sciences Program Data collection for the proposed dissertation
      analysis was done by the research teams and investigators from Rakai Health Sciences Program
      (RHSP) which was established in 1988 with a focus on HIV/AIDS research, including evaluation
      of health education and condom promotion. Over time activities have increased in nature and
      volume and expanded to include laboratory and clinical research, randomized trials of new
      prevention strategies, health professional training, expanded community services including
      HIV voluntary testing and counseling, provision of HIV antiretroviral therapy (ART), general
      and HIV-related medical care, prevention of mother-to-child transmission of HIV (PMTCT), and
      family planning services. In 2002, the Rakai Program became an International Center for
      Excellence in Research (ICER), sponsored by the National Institute of Allergy and Infectious
      Diseases (NIAID). The core of the RHSP is the 18-year community-based longitudinal Rakai
      Community Cohort Study (RCCS), within which the RHSP has implemented multiple
      interdisciplinary studies. Over 150 peer-reviewed papers have been generated from the RCCS
      and its nested studies.

      Data Source: Rakai Community Cohort Study All data for the proposed analysis were derived
      from the Rakai Community Cohort Study (RCCS) which conducts survey interviews every 12-18
      months with all consenting people aged 15-49 in ~5,000 households in 47-50 communities
      throughout Rakai. These 47-50 communities represent 7% of the 720 communities situated in
      Rakai District. The RCCS includes participants residing in trading centers and agrarian
      villages, representative of rural southwestern Uganda. Each RCCS participant receives a
      unique, life-long study identification number used to link data over time and between RHSP
      studies. RCCS written informed consent forms cover study participation, sample archiving for
      future assays including genetic testing, linkage of RCCS data to other RHSP databases, and
      permission to re-contact participants for other studies.

      Trial Design The SHARE intervention trial used a cluster randomized controlled design where
      study regions rather than individuals were selected to receive (or not receive) exposure to
      the intervention, with all consenting adults in the community being offered treatment
      (intervention). The community-based approach was selected because offering a partner violence
      prevention intervention to individuals without involving their intimate partners would not
      achieve holistic results. IPV involves both members of the couple and its prevention must
      likewise target both.

      The SHARE intervention trial was done via the Rakai Community Cohort Study (RCCS) which
      operates in ~50 communities which were aggregated into 11 study regions (categorized as rural
      or semi-urban) for a prior trial of sexually transmitted disease control and HIV transmission
      prevention conducted between 1994 and 1999. A previous FP outreach trial (1999 and 2002) had
      randomized these communities,35 and the SHARE study built on this prior randomization whereby
      the SHARE intervention was implemented in 4 regions (Buyamba, Kabira, Kalisizo, Katana) of
      the total 11 RCCS research areas. . For the current trial, four of the six FP intervention
      clusters were randomly assigned to the IPV intervention arm.

      The process used to select regions for exposure to the SHARE trial built on a previous
      cluster randomized trial (CRT) that was conducted between 1999 and 2002 to assess the impact
      of family planning outreach via social marketing in Rakai. For the family planning CRT, 5
      clusters were randomly selected to receive standard family planning services while 6 clusters
      were assigned to the intervention arm and received additional family planning information,
      counseling, and contraceptive methods from government service providers and community-based
      volunteer agents using social marketing and other strategies. Condom use was promoted in both
      control and intervention areas. Findings indicated family planning outreach via social
      marketing can significantly increase hormonal contraceptive use and decrease pregnancy rates.
      No differentials were found, however, in condom use between study arms.

      In 2005, 4 of the 6 family planning intervention clusters were randomly assigned to the
      intervention arm of the SHARE trial. The remaining 2 family planning intervention clusters,
      as well as all 5 family planning control clusters were assigned to the control arm of the
      SHARE intervention trial, making a total of 7 control regions in the SHARE trial. The
      decision to allocate only 4 communities to intervention was based on budgetary constraints
      which precluded a larger number of intervention areas.

      RCCS rounds and intervention trial implementation

      Data from 2 rounds of the RCCS, R1 and R2, will be analyzed for the proposed study:

      R1 = baseline, pre-intervention (Feb 2005-Jun 2006) R2 = post-intervention follow-up (Aug
      2006-Apr 2008) R3 = post-intervention follow-up (Jun 2008-Nov 2009)

      Baseline interviews were conducted in all 4 intervention and 7 control regions via RCCS
      between February 2005 and June 2006. SHARE was rolled out in the 4 intervention regions
      between August 2005 and November 2006. SHARE activities were introduced in each intervention
      region only after all baseline data collection had been completed for the entire study area.
      Because regions are surveyed via RCCS in the same order during each annual/semi-annual round,
      we estimate that each intervention community had approximately the same length of exposure to
      SHARE before each point of follow-up.

      Independent/Dependent Variables and Confounders

      Independent (exposure) variables

      There are 2 independent variables for the proposed study: RCCS round and arm of the trial

        1. RCCS round:

             1. Pre-intervention baseline (R1)

             2. Post-intervention follow-up time 2 (R2)

             3. Post-intervention follow-up time 2 (R3)

        2. Arm of trial

             1. Intervention arm

             2. Control arm

                Dependent (outcome) variables

                The primary dependent variable is past year experience of IPV (victimization among
                women, perpetration among men). Secondary outcome variables include number of
                non-marital sexual partners, condom use in the past 6 months, alcohol use at last
                sex and HIV incidence. All dependent variables will be determined at baseline,
                post-intervention time 1 and time 2.

                Confounders Potential confounding variables will be assessed at baseline to
                determine comparability between arms. The association between potential confounders
                and outcomes of interest will be assessed by univariate analyses, and potential
                covariates will include; age, sex (gender), education, marital status, religion,
                pregnancy-status, reproductive/fertility preferences, HIV-status, use of VCT,
                household socio-economic status. We will also assess the associations between
                sexual behaviors and IPV/HIV acquisition.

                Intention to Treat An intention to treat approach will be used in which all
                participants with evaluable data for each outcome measure will be included in the
                analysis by randomization arm. Retention rates will be estimated by arm.

                Analysis Plans The proposed statistical analysis will follow four key steps.

                Step 1 - Establish baseline comparability

                First, the characteristics of study participants will be assessed at
                pre-intervention (baseline) in both the control and intervention regions.
                Comparability of the two arms at baseline is important for designing final
                statistical analysis models capable of adjusting for any differences and assessing
                the impact of the intervention with minimal or no confounding. Pre-intervention
                data on outcome variables, socio-demographic and covariates will be analyzed, using
                descriptive statistics and graphics to display in the control and intervention
                communities. Exploratory analysis will include frequencies for dichotomous and
                categorical variables, using X2 and Fisher's exact tests for differences in
                proportions. Continuous variables will be assessed by means and medians using
                t-tests and Wilcoxon rank test.

                Step 2 - Investigate associations between intervention exposure and
                primary/secondary outcomes

                The second analytic step will be to investigate the associations between
                intervention exposure and the primary and secondary outcomes (past year IPV, condom
                use, alcohol use with sex, number of non-marital partners and HIV incidence) using
                univariate regression analyses. Covariates (characteristics or behaviors) found to
                be correlated with outcomes of interest in the univariate models at the p<0.15
                significance levels will be included in subsequent multivariate models.

                Step 3 - Construct adjusted multivariate models

                Adjusted multivariate regression models will be constructed for outcomes found to
                be significantly predicted by intervention exposure. Details are provided in the
                subsequent section on data modeling and power calculations for the 3 aims of the
                proposed dissertation research.

                Proposed Data Modeling and Power Calculations by Research Aim

                AIM 1 - Intimate Partner Violence Outcome To assess the impact of SHARE + RHSP
                community services on report of victimization from and perpetration of physical
                and/or sexual IPV in the past 12 months, compared to the impact of RHSP community
                services alone.

                Statistical Modeling for Aim 1

                The measures of past year experience of IPV will be analyzed separately for
                physical and sexual IPV and both will be modeled categorically. Three categories of
                physical violence will be used: (1) None (referent); (2) Moderate physical IPV; (3)
                Severe physical IPV. Two categories of sexual violence will be used: (1) None
                (referent); (1) Any sexual violence. Participants who report any experience
                (victimization or perpetration) of physical or sexual IPV in the past 12 month will
                be counted as having experienced the outcome.

                The proportion of each type of IPV will be tabulated by follow-up visit, and
                unadjusted differences between trial arms will be assessed using χ2 and Fisher's
                exact tests. The proportion of each type of IPV will be calculated separately for
                men (perpetration) and women (victimization). Behavior changes will be evaluated
                from baseline to follow-up (i.e. the second post-trial follow-up) by which time
                individuals in intervention regions had been exposed to the SHARE intervention for
                more than one year.

                Linear regression models will be fitted to estimate the marginal distributions of
                repeated outcomes to compare the within-individual behavior changes in relation to
                exposure or non-exposure to the intervention. The following equation will be used
                where Yit denotes the absence/presence of each type of IPV for every unit i at each
                time t.

                Yit = β0 + β1G + β2T + β3(G×T) + β4X1... + βkXk +εit

                Covariates included in the multivariate models will be characteristics or behaviors
                found to be correlated with IPV outcomes in univariate analyses at p<0.15. Models
                will also adjust for any statistically significant lack of comparability between
                the trial arms at baseline. Statistical inference for individual covariates will be
                based on the Wald statistic, and model fit assessed by the log likelihood ratio
                test (LRT).

                The difference between follow-up and baseline measures of IPV will be calculated
                separately for intervention and control regions and the difference in changes will
                be assessed under the null hypothesis that there is no DiD: (IPV-IntFup - IPV-IntB)
                = (IPV-CF - IPV-Cb). The statistical significance of the interaction coefficient,
                β3, will be obtained using the Wald statistic, and model fit assessed by the log
                likelihood ratio test (LRT). All hypothesis tests will be two sided with
                significance levels of 0.05.

                Behavioral variables found to have changed significantly during the post-trial
                follow-up will be further analyzed through repeated fitting of the linear model
                analyses stratifying by age group, type of community (rural vs. urban), and other
                important variables to investigate if behavior changes are associated with specific
                characteristics of individuals or populations.

                Power Calculations for Aim 1 Data on the impact of SHARE + RHSP community services
                on past year IPV will be analyzed to present (1) the percent change (reduction or
                increase) or lack thereof of reports of the IPV outcome in both groups
                (intervention and control) from baseline to follow-up; (2) the difference in the
                percent change of the IPV outcome between intervention and control groups.

                For Aim 1, power estimates were calculated to assess the study's power to measure
                percent change (reduction or increase) of IPV from baseline to follow-up, assuming
                there will be comparability in the percentages reported pre-intervention in both
                arms. Thus, study power estimates were calculated for the primary outcome of past
                year IPV based on (1) the set sample size for each round of data collection, (2)
                baseline prevalence of each type (physical and sexual) of IPV (3) assumptions
                regarding the expected magnitude of decline in each type of IPV that might result
                from the SHARE intervention combined with RHSP HIV prevention activities.

                Two sets of power calculations were used for physical IPV (moderate and severe
                combined) and sexual IPV. The sample size is fixed as per Table 3. STATA 1059 was
                used to estimate power to detect a minimum percent reduction, assuming a two-sided
                α = 0.05 with an approximate intervention population of 3,500 and an approximate
                control population of 11,100 at both time points. Baseline prevalence of different
                IPV types are based on RCCS data suggesting 20% of women experienced physical IPV
                and 14.5% experienced sexual IPV during the year before the survey. It is thus
                estimated that the study has 80% power to detect as little as a 7% reduction in the
                proportion of individuals reporting physical IPV and as little as a 16% reduction
                in the proportion of individuals reporting sexual IPV in both arms between baseline
                and follow-up.

                AIM 2 - Sexual Risk Behavior Outcomes To assess the impact of SHARE + RHSP
                community services on report of sexual risk behaviors, including non-marital
                partnerships in the past year, condom use over the past 6 months and use of alcohol
                before sex among men and women compared to the impact of RHSP community services
                alone.

                Statistical Modeling for Aim 2 The three measures of past year sexual risk
                behaviors will be analyzed separately for non-marital partnerships, condom use in
                the past 6 months, and alcohol use at last sex. All outcomes will be modeled
                categorically.

                Non-marital partners Number of non-marital sex partners in the past year will be
                modeled as a categorical outcome: (1) no non-marital partner (referent); (2) one
                non-marital partner; (3) two or more non-marital partners.

                Condom use in the past 6 months Condom in the past 6 months will be modeled
                categorically as: (1) no condom use (referent); (2) inconsistent use; and (3)
                consistent use.

                Alcohol use at last sex Alcohol use at last sex will be modeled categorically as:
                (1) no alcohol use at last sex (referent); (2) any alcohol use at last sex.

                The proportion of each type of sexual risk behavior reported will be tabulated by
                follow-up visit, and unadjusted differences between trial arms will be assessed
                using χ2 and Fisher's exact tests. The proportion of each type of IPV will be
                calculated separately for men and women and behavior changes will be evaluated from
                baseline to follow-up.

                Linear regression models will be fitted to estimate the marginal distributions of
                repeated outcomes67 to compare the within-individual behavior changes in relation
                to exposure or non-exposure to the intervention. The following equation will be
                used where Yit denotes the absence/presence of each type of sexual risk behavior
                for every unit i at each time t: Yit = β0 + β1G + β2T + β3(G×T) + β4X1... + βkXk
                +εit The remainder of the description of statistical methods for Aim 2 is identical
                to that of Aim 1.

                Power Calculations for Aim 2 Estimates were calculated to assess the study's power
                to measure percent change (reduction or increase) of each sexual risk behavior from
                baseline to follow-up, assuming comparability at baseline in in both arms. Again,
                study power estimates were calculated were based on (1) the set sample size for
                each round of data collection and (2) baseline prevalence, derived from Rakai data,
                of each type of sexual risk behavior. Three sets of power estimates were
                calculated.

                Non-marital partners: Rakai data indicated approximately 61% of men and 10% of
                women had more than one non-marital sex partner in the past year,49 the proposed
                analysis has 80% power to detect as small as a 3% reduction in men and an 11%
                reduction in women from time one to time two in each arm.

                Condom use: Data on condom use in the last six months was not available. But it is
                estimated that 6.5% of men and 3% of women consistently used condom use in the past
                year. 49 Based on these findings, it is estimated that the proposed analysis has
                the power to detects as small as 15% increase in consistent condom use among women
                and as small as a 23% increase in consistent condom use among men.

                Alcohol use at last sex: Previous Rakai findings suggest that 75.5% of men and 37%
                of women drink alcohol before sex. Based on these findings, it is estimated that
                the proposed analysis has the power to detect as small as 2% and 5% decrease in
                alcohol use with sex among men and women, respectively.

                AIM 3 - HIV Incidence Outcome To assess the impact of SHARE + RHSP community
                services on HIV incidence. Statistical Modeling for Aim 3

                For Aim 3, data from all 3 rounds of RCCS will be analyzed. Person years (PY) of
                exposure will be cumulated from baseline to the last negative HIV result if the
                person remained negative, or to the midpoint of the interval between the last
                negative tests and first positive tests for seroconverters. HIV incidence will be
                estimated per 100 PY. The primary analysis will be intention-to-treat, using a log
                link and Poisson distribution to estimate the incidence rate ratios (IRR) of HIV
                acquisition. Random effects models will be used to account for intra-region
                correlation. All models will be adjusted by study region. In univariate analyses we
                will assess covariates associated with HIV acquisition at p<0.15 to determine
                potential confounders for inclusion in multivariate models. Models will also adjust
                for any statistically significant baseline differences between randomization arms.

                Potential covariates include terms for sex, age, sexual risk behaviors, and
                community baseline prevalence of HIV. Homogeneity of the treatment effect in men
                and women will be assessed by testing for a sex by treatment interaction. Results
                of these models will be used to estimate the number of HIV infections prevented by
                the intervention over a ~4.5 period per 100 participants.

                Power Calculations for Aim 3 Assuming 75% annual retention and two follow up
                intervals post-intervention, we estimate we will have ~4,753 PY of exposure in the
                intervention group and ~16,969 PY of exposure in the control group. The power to
                detect minimal IRRs with this person time was estimated using STATA 1059 assuming a
                two sided α =0.05 and an HIV incidence estimate of 1.5/100 PY among women and
                1.4/100 PY among men. The study has 80% power to detect a 36% lower HIV incidence
                in intervention compared to control communities over time of follow-up.

                ETHICAL CONSIDERATIONS Several steps were taken by the RHSP to ensure the safety
                and confidentiality of all research participants. Because this is secondary data
                analysis, the main risk is breach of confidentiality if participant records,
                interviews or lab results are revealed to third parties. Informed consent documents
                are retained in locked filing cabinets and store rooms, accessible only to senior
                investigators or designated staff. All questionnaires and samples are identified by
                pre-printed study ID numbers, and names are removed. All questionnaires are stored
                in secure, locked facilities in the field station in Kalisizo and permanent stores
                in Entebbe. Only designated staff members have access to these records. All
                computerized data bases contain study ID numbers and the lists linking study
                numbers to names is kept separately in a password protected computer accessible
                only to senior data managers. Files of lab results are maintained in a separate
                safe computer file, with study ID numbers, and contain no personal identifiers.

                The RCCS interviews for this study were conducted in the respondents' homes or at a
                central location (referred to as a "hub"). Interviews were done in complete privacy
                in the language of Luganda by experienced same-sex interviewers using structured
                questionnaires. Recognizing that research on IPV raises important ethical and
                methodological challenges beyond those posed by general population health research,
                RHSP investigators followed recommendations developed by the WHO regarding the safe
                and ethical conduct of domestic violence research.

                IRB approval for the original study data was granted under two studies "Rakai
                Community Cohort Study" and "Assessing the impact of community-based intervention
                designed to reduce levels physical and sexual domestic violence in Rakai District,
                Uganda." The "Rakai Community Cohort Study" received IRB approval from WIRB (WIRB
                PRO#20031318) and the study "Assessing the impact of community-based intervention
                designed to reduce levels physical and sexual domestic violence in Rakai District,
                Uganda" received approval from the IRB of the World Health Organization
                (WHO.A55085). Both studies also received ethical approval from the Uganda Virus
                Research Institute's Science Ethics Committee and the Ugandan National Council of
                Science and Technology. Ethical approval for the proposed secondary analysis was
                received by WIRB as a sub study to the ongoing Rakai Community Cohort study (WIRB
                PRO#20031318). All enrollment and data collection has ended.
    

Intervention name(s): The SHARE Project
Intervention type(s): Behavioral
Intervention description(s): SHARE aimed to reduce IPV and used methodologies from two proven successful violence prevention frameworks: Stepping Stones (Welbourn, 1995) and the Resource Guide for Mobilizing Communities to Prevent Domestic Violence (Michau & Naker, 2003). SHARE promoted a process of social change based on the Transtheoretical Model's Stages of Change Theory (Prochaska & DiClemente, 1983; Prochaska & Velicer, 1997) which posits that although people realize they need to make changes in their life, they do it in stages instead of one major life change. There are five main stages of change: (1) pre-contemplation, (2) contemplation, (3) preparation for action, (4) action and (5) maintenance.
We hypothesized that repeated exposure to the ideas included in SHARE would encourage men and women to begin a process of change that results in preventive behavior.
Allocation: Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: HIV; Intimate partner violence; Community based prevention intervention; Uganda; Cluster randomized trial