Constantinou P, et al. - Researchers conducted a cohort study to develop and validate two outcome-specific morbidity indices in a population-based setting: the Mortality-Related Morbidity Index (MRMI) predictive of all-cause mortality and the Expenditure-Related Morbidity Index (ERMI) predictive of healthcare expenditure. For this investigation, all beneficiaries of the main French health insurance scheme aged 65 years or older on December 31, 2013 (N=7,672,111) was randomly split into a development population for index elaboration and a validation population for predictive performance assessment. According to outcomes of interest, the proposed MRMI and ERMI indices were performant tools to account for health-state severity.