RESUMEN
BACKGROUND: Previous operational research studies have demonstrated the feasibility of large-scale public sector ART programs in resource-limited settings. However, organizational and structural determinants of quality of care have not been studied. METHODS: We estimate multivariate regression models using data from 13 urban HIV treatment facilities in Zambia to assess the impact of structural determinants on health workers' adherence to national guidelines for conducting laboratory tests such as CD4, hemoglobin and liver function and WHO staging during initial and follow-up visits as part of Zambian HIV care and treatment program. RESULTS: CD4 tests were more routinely ordered during initial history and physical (IHP) than follow-up (FUP) visits (93.0 % vs. 85.5 %; p < 0.01). More physical space, higher staff turnover and greater facility experience with ART was associated with greater odds of conducting tests. Higher staff experience decreased the odds of conducting CD4 tests in FUP (OR 0.93; p < 0.05) and WHO staging in IHP visit (OR 0.90; p < 0.05) but increased the odds of conducting hemoglobin test in IHP visit (OR 1.05; p < 0.05). Higher staff burnout increased the odds of conducting CD4 test during FUP (OR 1.14; p < 0.05) but decreased the odds of conducting hemoglobin test in IHP visit (0.77; p < 0.05) and CD4 test in IHP visit (OR 0.78; p < 0.05). CONCLUSION: Physical space plays an important role in ensuring high quality care in resource-limited setting. In the context of protocolized care, new staff members are likely to be more diligent in following the protocol verbatim rather than relying on memory and experience thereby improving adherence. Future studies should use prospective data to confirm the findings reported here.