Monitoring the level of health and inequality over time using the Population Health Performance Index

Abstract Background The Population Health Performance Index (PHPI) is a composite measure that combines average health outcomes and their distribution within a population, thereby allowing for a comprehensive assessment of population health and inequality. The aim of this study is to examine the extent to which the PHPI adds value to monitoring of health and inequality over time in comparison to absolute and relative inequality. Methods Data from the WHO Equity Monitor database on under-5 mortality disaggregated by wealth quintiles for Nepal, Ethiopia, Peru, Rwanda, and Zimbabwe were analysed using different years between 1994 and 2020. Descriptive comparative statistics were employed to assess trends in the PHPI and conventional pairwise measures of absolute and relative inequalities, with consideration of different weights for inequality aversion. Results PHPI trends correspond to the trend of absolute inequality in all five countries, although they exhibit less volatility over time. Relative inequality follows the trend of the PHPI in only two of the five countries (Ethiopia and Zimbabwe), reflecting the methodology utilised for the PHPI. PHPI scores vary based on different inequality aversion weights, highlighting the sensitivity of the index to methodological adjustments. Conclusions The PHPI demonstrates notable convergence of trends with conventional methods, thereby substantiating its utility as a comprehensive tool for the simultaneous measurement of health and inequality. As it is able to consider both absolute and relative inequality within its own calculations, the PHPI allows for independent analysis of its two key components. The PHPI facilitates a more nuanced understanding of population health and may be more easily understood by policymakers and other stakeholders. As it does not address the underlying causes of changes in health inequalities, further research is necessary to supplement monitoring activities. Key messages • PHPI is a valuable tool for health and inequality monitoring by integrating both average health and disparity in a single index, facilitating communication of trends over time. • The dual focus complements conventional methods with its multidimensionality and may enable stakeholders to assess health and inequalities in alignment with broader health policy objectives.