Cost-Effectiveness Analysis of Three Leprosy Case Detection Methods in Northern Nigeria

Background: Despite several leprosy control measures in Nigeria, child proportion and disability grade 2 cases remain high while new cases have not significantly reduced, suggesting continuous spread of the disease. Hence, there is the need to review detection methods to enhance identification of early cases for effective control and prevention of permanent disability. This study evaluated the cost-effectiveness of three leprosy case detection methods in Northern Nigeria to identify the most cost-effective approach for detection of leprosy. Methods: A cross-sectional study was carried out to evaluate the additional benefits of using several case detection methods in addition to routine practice in two north-eastern states of Nigeria. Primary and secondary data were collected from routine practice records and the Nigerian Tuberculosis and Leprosy Control Programme of 2009. The methods evaluated were Rapid Village Survey (RVS), Household Contact Examination (HCE) and Traditional Healers incentive method (TH). Effectiveness was measured as number of new leprosy cases detected and cost-effectiveness was expressed as cost per case detected. Costs were measured from both providers' and patients' perspectives. Additional costs and effects of each method were estimated by comparing each method against routine practise and expressed as incremental cost-effectiveness ratio (ICER). All costs were converted to the U.S. dollar at the 2010 exchange rate. Univariate sensitivity analysis was used to evaluate uncertainties around the ICER. Results: The ICER for HCE was $142 per additional case detected at all contact levels and it was the most cost-effective method. At ICER of $194 per additional case detected, THs method detected more cases at a lower cost than the RVS, which was not cost-effective at $313 per additional case detected. Sensitivity analysis showed that varying the proportion of shared costs and subsistent wage for valuing unpaid time did not significantly change the results. Conclusion: Complementing routine practice with household contact examination is the most cost-effective approach to identify new leprosy cases and we recommend that, depending on acceptability and feasibility, this intervention is introduced for improved case detection in Northern Nigeria. Author Summary: Reported increases in child proportions and disability grade 2 cases in Nigeria suggest that leprosy disease is still spreading in the country. This indicates the need to review case finding strategies to improve case detection for effective control of the disease. It was necessary that available methods be assessed for their value for money in view of limited resources. We evaluated the cost-effectiveness of three available leprosy case detection methods using data available from 2005 to 2011. We explored data to determine which strategy when implemented in addition to routine practice would detect most additional leprosy cases at a given cost (measured in U.S. dollars). Hence, cost-effectiveness was expressed as incremental cost-effectiveness ratio (ICER). Our findings show that at the rate of $142 per additional case detected, the household contact examination was the most costeffective strategy for detecting additional leprosy cases when implemented to complement routine practice.