Health investments and well-being of middle-aged and elderly populations: a panel data analysis based on China

Abstract Background As the global population ages and life expectancies rise, improving the health and equity of middle-aged and older individuals has become a universal goal, especially with the economic benefits of the demographic dividend decreasing. Health investments (HI), which are crucial for improving health outcomes (HO) and protecting human capital, play a key role in achieving these objectives. This study aims to examine the impact of HI on the health status of middle-aged and elderly individuals, analyze issues of health equity among this population, and enhance their overall health level while fostering economic growth. Methods This study, based on Grossman’s health demand theory and China Health and Retirement Longitudinal Study (CHARLS) data from 2011 to 2020 (n = 11,138), examines middle-aged and elderly individuals (aged 45 years and above) across 28 Chinese provinces. A panel data model is used to assess HI and HO, with composite indices created using the entropy method. HI includes leisure, healthcare, and living environments, whereas HO covers self-reported short- and long-term health. A high-dimensional fixed-effects model is used to analyze the impact of HI on HO. Health equity is explored using the income Gini coefficient, health investment concentration index (I-CI), and health outcome concentration index (H-CI), with decomposition performed using the Shapley method. Results HI positively affects HO in middle-aged and elderly individuals in China. The key factors that influence HO are gender, age, household registration (HR), and income. Income inequality is significant, with an average Gini coefficient of 0.492. The I-CI averages 0.081, indicating higher investment concentration among wealthier groups. The major factors that influence the I-CI are household registration (34.9%), income (33.1%), employment (18.8%), and education (11.7%). The H-CI averages 0.033, with better outcomes associated with higher education. The key factors influencing H-CI are age (46.7%), gender (16.7%), income (15.2%), and education (10.7%). Conclusion HI significantly improves the HO and enhances the health human capital of middle-aged and elderly individuals. However, these investments tend to favor wealthier groups, whereas HO are more favorable among those with higher education. Income and education levels are the key drivers of inequity in both HI and HO.