The Impact of Alternate Methodological and Structural Assumptions on Results of Cost-effectiveness Analysis: Empirical Evidence using Three Indian Economic Evaluations.

BackgroundDespite advancement in methods and application of economic evaluations (EEs), there are several uncertainties.ObjectivesTo assess the impact of alternate methodological and structural assumptions for four key principles of EE, on the results of cost-effectiveness analysis.Materials and methodsThree previously published model-based EEs were used: (1) Integrated Management of Neonatal and Childhood Illnesses (IMNCIs) intervention; (2) intervention for multiple myeloma, and (3) safety-engineered syringes (SES) intervention. A series of empirical analyses was undertaken to assess the impact of alternate assumptions for discount-rate, time-horizon, study perspective, and health outcome measure, on incremental cost-effectiveness ratio (ICER), and interpretation of cost-effectiveness.ResultsIncreasing discount rate resulted in an increase in ICERs, for all three case-studies; however, there was no change in the conclusions. Using shorter time-horizons resulted in a significant increase in ICERs, the multiple myeloma intervention remained cost-ineffective, SES intervention became cost-ineffective, whereas IMNCI intervention remained cost-effective, despite a three-fold increase in ICER. On using disability adjusted life years instead of quality adjusted life years, ICERs increased to 0.04, 2 and 4 times for SES, IMNCI and multiple myeloma interventions, respectively. On analyzing results from a societal perspective, a decline in ICERs was observed. The decline was significant for IMNCI where the intervention turned dominant/cost-saving. In the other two case-studies decline in ICERs was modest, 32% for multiple myeloma, and 4% for SES.ConclusionWe observed a significant impact of using alternate assumptions on ICERs which can potentially impact resource-allocation decisions. Our findings provide strong argument in favor of standardization of processes and development of country-specific guidelines for conduct of EE.