Health Results-Based Financing Impact Evaluation, Baseline and Endline Household Surveys 2011-2015

Within each province (except for Northern and Southern Provinces, where six districts were sampled), three districts at or near a derived provincial median index score were selected and then randomly assigned to each of the three arms. Thus, there are a total of 30 districts distributed equally among the three study arms with 10 districts in each.

For statistical purposes, each district in Zambia is subdivided into Census Supervisory Areas (CSAs), which in turn nests Standard Enumeration Areas (SEAs). Thus, for data collection purposes, the SEA is the smallest geographical unit above the household and is the primary sampling unit (PSU). The SEAs were sampled from the catchment areas of selected health facilities. The sampling frame of SEAs in each treatment arm was arrived at by digitally overlaying SEA maps (obtained from the CSO) with health facility catchment area maps. After grouping the PSUs by stratum (treatment vs control), the sample was then selected in two stages: i) selection of PSUs in the first stage using probability proportional to size, and ii) selection of 10 eligible households, or secondary sampling units (SSUs), in the second stage using systematic random sampling. Prior to household selection, a full PSU listing of eligible households (households with a pregnancy related outcome, i.e. live birth, stillbirth, abortion and miscarriage within the two years prior to the survey) was undertaken by the survey team in each cluster. At baseline, 3,064 households in the relevant districts were surveyed at baseline, and 3,500 households at follow up. Health facilities were selected by a simple random sampling technique. In the baseline, 176 health facilities were surveyed whereas 210 were surveyed in the endline.