Can volunteer community health workers manage multiple roles? An interrupted time-series analysis of combined HIV and maternal and child health promotion in Iringa, Tanzania.

Community health workers (CHWs) play a critical role in health promotion, but their workload is often oriented around a single disease. Renewed interest in expansion of multipurpose CHWs to cover an integrated package of services must contend with the debate over how effectively CHWs can perform an increased range of tasks. In this study, we examine whether an existing cadre of HIV-focused paid volunteer CHWs in Iringa, Tanzania, can take on new maternal, newborn and child health (MNCH) promotion tasks without adversely affecting their HIV role. HIV household visits conducted per month were extracted from CHW summary forms covering up to 14 months pre-intervention and 12 months of intervention data. A comparative interrupted time series using a generalized estimating equation assessed population-averaged longitudinal trends in monthly HIV visit count in the intervention ('dual-role' CHWs) vs comparison group ('single-role' CHWs). Analyses were stratified by district, accounting for secular trends, seasonality and covariates. The time series consisted of 4022 observations for HIV visit count from 187 CHWs (41% dual role). Prior to MNCH training, dual-role CHWs averaged 25-30% more HIV visits per month compared with single-role CHWs, with no other significant pre-intervention differences between groups. CHWs began conducting MNCH visits shortly after receiving training, but in the initial month of intervention, there was a 6-9% drop in the mean number of HIV visits per month among dual-role CHWs. Otherwise, there was no significant difference between single- and dual-role CHWs in the trajectories of monthly HIV visits before and after adding MNCH tasks. Dual-role CHWs appeared able to maintain their HIV client workload after adding MNCH tasks to their routines, albeit with an initial slight decline in HIV workload. This dual-role CHW model suggests potential spare capacity in vertically oriented programmes, with productivity gains possible through integration.