Chronic conditions and multimorbidity in population aged 90 years and over: associations with mortality and long-term care admission

Background: prevalence of many chronic conditions is rising in the aging population worldwide. However, the long-term impact of these conditions and multimorbidity on other health outcomes in very old age is rarely studied. Methods: the data were based on four waves of the Vitality 90+ Study conducted in 2001, 2003, 2007 and 2010. Associations of chronic conditions and multimorbidity with mortality were analysed in a total sample of 2,862 people aged over 90, and associations with long-term care (LTC) admission in a subsample of 1,954 participants living at home in baseline. Risk of death and LTC admission were assessed with Cox and competing risks regression with time-dependent covariates. Population attributable fractions (PAF) for mortality and LTC admission were calculated for chronic conditions based on the regression models. Results: heart disease, diabetes and dementia predicted mortality in men and women. In addition, depression was associated with increased mortality in women. Parkinson's disease, dementia and hip fracture predicted LTC admission in women. Multimorbidity increased the risk of death and LTC admission in women but not in men. For both genders, dementia had the highest PAF for mortality and LTC admission. Conclusion: heart disease and diabetes are still important predictors of mortality in very old age. However, the role of dementia is pronounced in this age group. Of the studied conditions, dementia is the main contributor both to mortality and LTC admission. Multimorbidity has predictive value concerning both mortality and LTC admission, at least in oldest old women.