Health Dynamics through Composite Index of Health Status

Background: Improved health is positively associated with economic benefits and improved societal Quality of life (QOL). Health can be measured by a composite index combining relevant dimensions and indicators pertaining to activities of daily living, physical and cognitive functions, emotional well-being, feelings, etc. This involves appropriate biomarkers, patient-reported questionnaires and performance-based scales giving rise to ratio scale data, count data, ordinal data and categorical confounders. Method: The paper transforms scores of biomarkers, item scores of scales to form normally distribution resulting in meaningful addition of ratio level data and ordinal data and derivation of an index reflecting overall health status (I_Health) which follows normal distribution, satisfies desired properties and facilitates assessment of changes over time, better evaluation of psychometric qualities. Results: Dimensions of I_(Health )can be ranked by(Change in I_(Health ))/(Unit change in a dimension.). Health dynamics is reflected by changes in I_(Health )of one patient or sample of patients across time along a disease continuum across categorical variables like gender, income, educational levels, stages of disease, etc. Normally distributed index can help to test equality across groups, using χ^2-test. Computation of separate index is recommended for vulnerable groups like old aged citizens, postpartum women running the risk of maternal mortality, economically backward class, etc. Conclusions: The proposed index 〖I_Health〗_i contributes to improve evaluation of tests and QOL, undertaking parametric analysis for better comparisons, stratification, and integration is recommended.