Cost-effectiveness analysis of inborn organic acidemias screening in Hong Kong newborns

Abstract

OBJECTIVE To assess cost-effectiveness of population-wide tandem mass spectrometry (TMS) based newborn screening strategy for organic acidemias (OA)in Hong Kong from the public provider’s perspective.

METHOD A decision tree was established to model the effect of screening on a hypothetical cohort of newborn babies compared with no screening. 5-year after birth was marked as the effective point for measurement. Screening test performance, probabilities of outcomes and costs were obtained from literature and from local sources. Yearly discount rate of 3% was applied for cost and benefit.

ANALYSIS Incremental cost-effectiveness ratio (ICER) was calculated per life year gained and per life year gained without mental retardation, using $390,000 as cost-effective threshold. Sensitivity analysis and threshold analysis were performed on major estimates.

RESULTS With screening, ICER per life year gained is $1,862,503 and the ICER per life year gained without mental retardation is $485,870, when compared with no screening strategy. Both ICERs does not reach cost-effective threshold of $390,000. The population-wide screening does not appear economically favourable to avoid mortality and mental retardation from a provider’s perspective.

Sensitivity analysis showed that ICERs are most sensitive to specificity of the screening test. From threshold analysis, ICER per life year gained reaches cost-effectiveness threshold for (1) incidence rate higher than 1 in 19,894; or (2) for OA mortality rate higher than 86%; or (3) at screening cost lower than $43.2. ICER per life year gained without mental retardation reaches cost-effectiveness threshold for (1) incidence rate higher than1 in 31,630; or (2) for higher than 86% probability of developing mental retardation among OA cases; or (3) for screening cost lower than $69.At any screening cost lower than $34.01or incidence higher than 1 in 15752, screening strategy becomes cost-saving and dominating over no screening strategy for both outcomes.

CONCLUSION With base case estimates, the population-wide screening does not appear economically favourable to avoid mortality and mental retardation development within the 5-year study period. More local evidence is required for more realistic assessment. Further cost-effectiveness analyses of screening multiple diseases are needed to optimize the TMS-based screening strategy for Hong Kong newborn.