Sajesh K Veettil, Christy Thomas, Chan Jia En, Manuel Meraz, Teerapon Dhippayom, Muhammed Rashid, Jeong-Yeon Cho, Ratree Sawangjit, Filip Meheus, Andrew Mirelman, Raymond Hutubessy, Nathorn Chaiyakunapruk
The INB approach is the most commonly used method. It quantifies cost-effectiveness, captures the direction and magnitude of effects, characterizes uncertainty, and highlights variation across studies, but is largely limited to high-and middle-income settings. Future research should address existing methodological challenges and its utility in low-income settings.
INTRODUCTION: Several quantitative approaches are available for synthesizing evidence from economic evaluations (EEs). This scoping review mapped the landscape of such studies, identified quantitative synthesis methods, and examined their frequency, settings, and study characteristics.
METHODS: Searches were conducted in PubMed, Embase, Epistemonikos, EconLit, and the DARE database from inception to October 2025. Eligible studies included those using quantitative methods to combine findings from multiple EEs. Studies were classified by synthesis method, with frequencies and distributions analyzed descriptively and summarized narratively.
RESULTS: A total of 63 studies were included. Most were from high- and middle-income countries, covering diverse health areas, with pharmacological interventions representing the largest proportion. Eight quantitative synthesis methods were identified, with meta-analysis of incremental net benefit (INB) being the most commonly applied (n = 44; 69.8%). Among non-INB methods, separate pooling of incremental costs and effects was most frequent (n = 9), followed by regression and meta-regression (each n = 3), and meta-analysis of incremental cost-effectiveness ratios (ICERs) (n = 2). Other methods, including reciprocal ICER ratios, cost-effect ratios, and network meta-analysis of INB, were each reported once. Over the past 5 years, the INB approach consistently surpassed non-INB methods, showing an increasing trend, although evidence from this approach remains largely confined to high- and middle-income countries.
CONCLUSIONS: The INB approach is the most commonly used method. It quantifies cost-effectiveness, captures the direction and magnitude of effects, characterizes uncertainty, and highlights variation across studies, but is largely limited to high-and middle-income settings. Future research should address existing methodological challenges and its utility in low-income settings.