Effectiveness of a multivitamin supplementation program among HIV-infected adults in Tanzania.

OBJECTIVE: The objective of this study was to assess the effectiveness of a routine multivitamin supplementation program for adults living with HIV in Tanzania. DESIGN: We conducted a retrospective cohort study of 67 707 adults enrolled in the Dar es Salaam HIV care and treatment program during 2004-2012. METHODS: The Dar es Salaam HIV care and treatment program intended to provide all adult patients with multivitamin supplements (vitamins B-complex, C, and E) free of charge; however, intermittent stockouts and other implementation issues did not afford universal coverage. We use Cox proportional hazard models to assess the time-varying association of multivitamin supplementation with mortality and clinical outcomes. RESULTS: The study cohort contributed 41 540 and 129 315 person-years of follow-up time to the antiretroviral therapy (ART)-naive and ART-experienced analyses, respectively. Among 48 207 ART-naive adults, provision of multivitamins reduced the risk of mortality [adjusted hazard ratio (aHR): 0.69; 95% confidence interval (CI): 0.59-0.81], incident tuberculosis (TB) (aHR: 0.83; 0.76-0.91), and meeting ART eligibility criteria (aHR: 0.78; 95% CI: 0.73-0.83) after adjustment for time-varying confounding. Among 46 977 ART-experienced patients, multivitamins reduced mortality (hazard ratio: 0.86; 95% CI: 0.80-0.92), incident TB (aHR: 0.78; 95% CI: 0.73-0.84), and immunologic failure (aHR: 0.70; 95% CI: 0.67-0.73). The survival benefits associated with provision multivitamins appeared to be greatest during the first year of ART and declined over time (P value <0.001). CONCLUSION: Multivitamin supplementation appears to be a simple, effective, safe, and scalable program to improve survival, reduce incidence of TB, and improve treatment outcomes for adult HIV patients in Tanzania.

Impact of Antiretroviral Therapy on the Risk of Herpes Zoster among Human Immunodeficiency Virus-Infected Individuals in Tanzania.

We examined the incidence of herpes zoster (HZ) before and after the initiation of antiretroviral therapy (ART), and risk factors for HZ among human immunodeficiency virus (HIV)-infected individuals in Tanzania. A cohort study was conducted among HIV-positive individuals enrolled in HIV care and treatment clinics in Dar es Salaam, Tanzania. A Cox proportional hazard model was used to examine the effect of ART on the risk of HZ after adjusting for sociodemographics and time-varying clinical and nutritional factors. Among 72,670 HIV-positive individuals, 2,312 incident cases of HZ (3.2%) occurred during the median follow-up of 15 months (interquartile range: 3-35). The incidence rate of HZ significantly declined from 48.9 (95% confidence interval [CI] = 46.7-51.0) per 1,000 person-years before ART to 3.7 (95% CI = 3.3-4.1) per 1,000 person-years after the initiation of ART (P < 0.001). The risk of HZ declined with longer duration on ART. Low CD4 cell count, older age, female sex, district of Dar es Salaam, and year of enrollment were independently associated with the risk of HZ in the multivariate analysis. Low body mass index and anemia were not associated with the risk of HZ. The risk of HZ substantially declined after ART initiation in this large cohort of HIV-infected individuals. Earlier initiation of ART could reduce the risk of HZ and other opportunistic infections among HIV-infected individuals in sub-Saharan Africa.

Intra-Cluster Correlation Estimates for HIV-related Outcomes from Care and Treatment Clinics in Dar es Salaam, Tanzania.

INTRODUCTION: Researchers planning cluster-randomized controlled trials (cRCTs) require estimates of the intra-cluster correlation coefficient (ICC) from previous studies for sample size calculations. This paper fills a persistent gap in the literature by providing estimates of ICCs for many key HIV-related clinical outcomes. METHODS: Data from HIV-positive patients from 47 HIV care and treatment clinics in Dar es Salaam, Tanzania were used to calculate ICCs by site of enrollment or site of ART initiation for various clinical outcomes using cross-sectional and longitudinal data. ICCs were estimated using linear mixed models where either clinic of enrollment or clinic of ART initiation served as the random effect. RESULTS: ICCs ranged from 0 to 0.0706 (95% CI: 0.0447, 0.1098). For most outcomes, the ICCs were large enough to meaningfully affect sample size calculations. For binary outcomes, the ICCs for event prevalence at baseline tended to be larger than the ICCs for later cumulative incidences. For continuous outcomes, the ICCs for baseline values tended to be larger than the ICCs for the change in values from baseline. CONCLUSION: The ICCs for HIV-related outcomes cannot be ignored when calculating sample sizes for future cluster-randomized trials. The differences between ICCs calculated from baseline data alone and ICCs calculated using longitudinal data demonstrate the importance of selecting an ICC that reflects a study's intended design and duration for sample size calculations. While not generalizable to all contexts, these estimates provide guidance for future researchers seeking to design adequately powered cRCTs in Sub-Saharan African HIV treatment and care clinics.

Predictors of Nonadherence to Antiretroviral Therapy among HIV-Infected Adults in Dar es Salaam, Tanzania.

BACKGROUND: Adherence rates of ≥95% to antiretroviral therapy (ART) are necessary to maintain viral suppression in HIV-infected individuals. We identified predictors of nonadherence to scheduled antiretroviral drug pickup appointments in a large HIV care and treatment program in Tanzania. METHODS: We performed a prospective cohort study of 44, 204 HIV-infected adults on ART between November 2004 and September 2012. Multivariate generalized estimating equation for repeated binary data was used to estimate the relative risk and 95% confidence intervals of nonadherence. RESULTS: Nonadherence was significantly greater among patients with high CD4 counts, high body mass indices, males, younger patients, patients with longer durations on ART, and those with perceived low social support. CONCLUSIONS: Targeted interventions should be developed to improve ART adherence among healthier, younger, and more experienced patients who are on ART for longer durations within HIV care and treatment programs. Social support for patients on ART should be emphasized.