Availability of volunteer-led home-based care system and baseline factors as predictors of clinical outcomes in HIV-infected patients in rural Zambia.

BACKGROUND: We assessed the impact of home-based care (HBC) for HIV+ patients, comparing outcomes between two groups of Zambians receiving antiretroviral therapy (ART) who lived in villages with and without HBC teams. METHODS: We conducted a retrospective cohort study using medical charts from Macha Mission Hospital, a hospital providing HIV care in Zambia's rural Southern Province. Date of birth, date of ART initiation, place of residence, sex, body mass index (BMI), CD4+ cell count, and hemoglobin (Hgb) were abstracted. Logistic regression was used to test our hypothesis that HBC was associated with treatment outcomes. RESULTS: Of 655 patients, 523 (80%) were eligible and included in the study. There were 428 patients (82%) with favorable outcomes (alive and on ART) and 95 patients (18%) with unfavorable outcomes (died, lost to follow-up, or stopped treatment). A minority of the 523 eligible patients (n = 84, 16%) lived in villages with HBC available. Living in a village with HBC was not significantly associated with treatment outcomes; 80% of patients in a village with HBC had favorable outcomes, compared to 82% of patients in a village without HBC (P = 0.6 by χ(2)). In bivariable analysis, lower BMI (P<0.001), low CD4+ cell count (P = 0.02), low Hgb concentration (P = 0.02), and older age at ART initiation (P = 0.047) were associated with unfavorable outcomes. In multivariable analysis, low BMI remained associated with unfavorable outcomes (P<0.001). CONCLUSIONS: We did not find that living in a village with HBC available was associated with improved treatment outcomes. We speculate that the ART clinic's rigorous treatment preparation before ART initiation and continuous adherence counseling during ART create a motivated group of patients whose outcomes did not improve with additional HBC support. An alternative explanation is that the quality of the HBC program is suboptimal.

Predictors of adherence to antiretroviral therapy in rural Zambia.

BACKGROUND/OBJECTIVE: Antiretroviral therapy (ART) adherence levels of >or=95% optimize outcomes and minimize HIV drug resistance. As such, identifying barriers to adherence is essential. We sought to assess travel to point-of-care for ART as a potential barrier to adherence in rural Zambia, within the context of patient demographics, perceived stigma, and selected clinical indices. METHODS: We studied 424 patients receiving ART from the Macha Mission Hospital (MMH). Interviews ascertained age, gender, education, perceived stigma, nearest rural health facility (RHF), and mode/cost/time of transport for each study participant. Motorcycle odometer and global positioning system way-points measured distance from the MMH to each of the RHFs, estimating patients' home-to-MMH travel distances. Body mass index, World Health Organization HIV/AIDS stage, and pill counts were assessed from review of patients' medical and pharmacy records. RESULTS: At least 95% adherence was documented for 83.7% of the patients in their first months of ART. Travel-related factors did not predict adherence. Adherence was higher for those on ART for a longer time (odds ratio = 1.04 per day; P = 0.002). CONCLUSIONS: Patients in rural Zambia can achieve adherence rates compatible with good clinical outcomes despite long travel distances. The MMH was able to provide quality HIV/AIDS care by implementing programmatic features selecting for a highly adherent population in this resource-limited setting.

Simultaneous inference for ratios of linear combinations of general linear model parameters.

Consider a general linear model with p -dimensional parameter vector beta and i.i.d. normal errors. Let K(1), ..., K(k ), and L be linearly independent vectors of constants such that L(T)beta not equal 0. We describe exact simultaneous tests for hypotheses that Ki(T)beta/L(T)beta equal specified constants using one-sided and two-sided alternatives, and describe exact simultaneous confidence intervals for these ratios. In the case where the confidence set is a single bounded contiguous set, we describe what we claim are the best possible conservative simultaneous confidence intervals for these ratios - best in that they form the minimum k -dimensional hypercube enclosing the exact simultaneous confidence set. We show that in the case of k = 2, this "box" is defined by the minimum and maximum values for the two ratios in the simultaneous confidence set and that these values are obtained via one of two sources: either from the solutions to each of four systems of equations or at points along the boundary of the simultaneous confidence set where the correlation between two t variables is zero. We then verify that these intervals are narrower than those previously presented in the literature.