Table 2

Variable categories, description, expected effect on costs and justification

Variable categoryVariable nameDescriptionExpected effect on costsJustificationSource
Dependent variableAverage costs per HIVST kit distributed including central costsUnit costs per HIVST kit distributed including in-country central costs and start-up costs in 2019 US$NANA12
QuantitiesScaleNumber of HIVST kit distributed by site during the observation period±(Dis)Economies of scalePSI
Site organisational characteristicsHIVST distributorsNumber of full time equivalent HIVST distributor in each site±Increase your coverage and # of HIVST kits distributed (so lower average costs per kit distributed), but also increase personnel costsPSI
Campaign styleVariable coded 1 if the same distributors travel from sites to sites (campaign style distribution) or 0 if they live within the community+In some countries, HIVST kits distribution was more conservative and restricted by campaign duration in each site, so this approach could drive costs higher due to lower volumes of kits distributed and travel costsPSI
EfficiencyNumber of HIVST kits distributed per agent per monthThe higher the number of HIVST kits distributed per agent, the more efficient they are and the lower is the cost per kit distributedPSI
Characteristics of population targeted% HIVST kits distributed to menNumber of kits distributed to men – also measure if programme is targeting well (proxy for quality)+Men might be harder to reach and to convince to take a kit, might lead to higher costs of provisionPSI
% never tested for HIV% of people who never tested for HIVHigher knowledge of HIV status might lead to lower demand for testing, including HIVST, leading to increased average cost per kit distributedSTAR household surveys
Environmental characteristicsDistanceDistance from central warehouse to site in kilometres+Longer distance from the PSI headquarters and warehouse might lead to high costs of service provisionPSI, Google Maps
Catchment populationSize of the catchment population of the site regardless of eligibilityNumber of potential HIVST recipients affect levels of distribution potentially leading to economies of scalePSI, Ministry of Health
Positivity at health facilityAnnual new HIV positive identified over total tested at nearby health facility (positivity rate)+If the health facilities experience high positivity rates, the demand for HIVST might be lower leading to increased average costs (higher costs to reach the last % of target population)PSI, Ministry of Health
HTS average cost at health facilityAverage cost per person tested with HTS at the nearest health facility+Although not a determinant, a significant correlation might suggest the effect of other unobserved environmental characteristics on costs12 24
Input price levelPrice levelPer capita Growth Domestic Product in 2019 US$+Proxy for input price level variation across countries52
  • HTS, HIV testing services; PSI, Population Services International; STAR, Self-Testing AfRica.