The contribution of dementia to the disablement process and modifying factors

The objective of this study was to examine the impact of dementia on disability progression and mortality, and to analyze the modifying effect of risk factors and extra-individual factors. A sample of 3,403 participants in the PAQUID study was followed for 10 years. Disability was assessed on a 4-grade scale: no disability, disabled only on the Rosow-Breslau scale, disabled on the Rosow-Breslau scale and on instrumental activities of daily living (IADL) scales, and disabled on the Rosow-Breslau, IADL and activities of daily living (ADL) scales. A Markov model was used to estimate the effect of explanatory variables on disability and mortality. Controlling for age, gender, education, place of residence, medical care and informal support, dementia had a strong significant effect on progression to IADL and then to ADL disability. Dementia did not increase the risk of death, once disability was taken into account, except from the lowest disability grade.