The cost of mapping trachoma: Data from the Global Trachoma Mapping Project

Background: The Global Trachoma Mapping Project (GTMP) was implemented with the aim of completing the baseline map of trachoma globally. Over 2.6 million people were examined in 1,546 districts across 29 countries between December 2012 and January 2016. The aim of the analysis was to estimate the unit cost and to identify the key cost drivers of trachoma prevalence surveys conducted as part of GTMP. Methodology and principal findings: In-country and global support costs were obtained using GTMP financial records. In-country expenditure was analysed for 1,164 districts across 17 countries. The mean survey cost was $13,113 per district [median: $11,675; IQR = $8,365-$14,618], $17,566 per evaluation unit [median: $15,839; IQR = $10,773-$19,915], $692 per cluster [median: $625; IQR = $452-$847] and $6.0 per person screened [median: $4.9; IQR = $3.7-$7.9]. Survey unit costs varied substantially across settings, and were driven by parameters such as geographic location, demographic characteristics, seasonal effects, and local operational constraints. Analysis by activities showed that fieldwork constituted the largest share of in-country survey costs (74%), followed by training of survey teams (11%). The main drivers of in-country survey costs were personnel (49%) and transportation (44%). Global support expenditure for all surveyed districts amounted to $5.1m, which included grant management, epidemiological support, and data stewardship. Conclusion: This study provides the most extensive analysis of the cost of conducting trachoma prevalence surveys to date. The findings can aid planning and budgeting for future trachoma surveys required to measure the impact of trachoma elimination activities. Furthermore, the results of this study can also be used as a cost basis for other disease mapping programmes, where disease or context-specific survey cost data are not available. Author summary: There are currently few data sets available to aid programmes in planning and budgeting for population-based surveys in low- and middle- income countries. With the objective of identifying cost drivers and key variables influencing prevalence survey costs, the authors collected expenses incurred during the Global Trachoma Mapping Project (GTMP) which surveyed 2.6 million people across 29 countries. Expenditure from surveying 1,164 districts in 17 countries was analysed. Our results showed that the majority of in-country expenditure was spent on personnel (per diems, accommodation, meals and beverages) (49%) and local transportation (44%) and that the median survey expenditure was US$11,675 per district (or US$15,839 per evaluation unit, US$625 per cluster and US$4.9 per person examined). There were large variations in survey unit costs across settings, based on local geographic, demographic, seasonal effects and local operational characteristics. In addition, the resources required for the global support and coordination of the GTMP were analysed and amounted to US$5.1m (US$3,318 per district or US$5,668 per EU). Global support expenses can be substantial for a large multi-country mapping exercise conducted in a limited period of time such as the GTMP. Findings from this study can be used to inform other disease mapping projects, and to inform planning and budgeting for the prevalence surveys that will assess the impact of trachoma elimination interventions.