Cost effectiveness of a latrine revision programme in Kabul, Afghanistan.

INTRODUCTION We assessed a household latrine revision intervention implemented in Kabul, Afghanistan for evidence of a reduction in diarrhoeal disease. METHODS A case-control design involving 1238 cases and 625 controls was used. Logistic regression modelling was performed both for children < 5 years and < or = 11 years, and the parameter estimates were later used with results from a stratified cluster sample survey. This survey used a verbal autopsy methodology to enable an estimation of the number of deaths averted over a 1-year period. A cost-effectiveness analysis using direct and indirect costs for the intervention was then conducted and the results compared with primary health care interventions identified from a Medline search. FINDINGS Conditional logistic regression showed that patients were less likely than controls to live in households with revised latrines (odds ratio (OR) 0.57, 95% confidence interval (CI) = 0.42-0.77 for children < 5 years, and OR 0.53, 95% = CI 0.41-0.67 for children < or = 11 years). The results from the survey of cause-specific mortality by verbal autopsy enabled estimation of the number of deaths averted over a 1-year period due to the intervention; these estimations were 235 (95% CI = 109-360) for children < 5 years and 285 (95% CI = 180-397) for children < or = 11 years. Estimates of cost effectiveness ranged from approximately US dollars 1800 to US dollars 4100 per death averted depending on age and payer perspective. CONCLUSION These estimates are conservative because only 1 year of effectiveness is considered, yet they compare favourably with a review of other paediatric interventions. These results are important because funding for sanitation interventions is often limited by the belief that the interventions are not cost-effective.