Factors associated with health status of older Americans.

BACKGROUND: health status is increasingly used as a measure of healthcare effectiveness. How diseases and symptoms are associated with health status is not completely understood.
OBJECTIVES: to find diseases, symptoms and demographic factors associated with physical and mental health status in older Americans.
METHODS: we analysed data from a survey of over 100 000 Medicare beneficiaries aged 65 and older. We used the short-form 36 physical and mental summary scores as measures of health status. Other data collected included demographic details, symptoms and diagnoses.
RESULTS: age as a single variable explained 4% of variation in physical health status. Adding other demographic information and increased disease burden explained variation to 8% and 27% respectively. Together, shortness of breath, back pain, difficulty getting in and out of chairs, arthritis of hip or knee, a recent change in health and age explained 54% of variation. All available variables explained 59%. The role of age as an independent factor decreased markedly after disease and symptoms were considered. Similar factors were associated with lower mental health status, but age was not.
CONCLUSION: these data suggest that heart and lung disease and back pain are the most important factors affecting the average physical health status of older people. Sex, marital status and race have very little independent effect. Efforts to improve average physical health status scores might best be targeted at these conditions rather than demographic characteristics. Mental health status does not decline with age, and similar factors affect it but to a lesser degree.