Samenvatting

Background:
Recent world population predictions show that the world population aged >=65 years will increase from 10% in 2022 to 16% in 2050. Population aging is accompanied by an increase in people with disability. It is important to pay special attention to people with disability, as these people are at high risk of adverse outcomes. Our study aimed to investigate the transitions of disability among Dutch community-dwelling older people aged 75 years or older, using a follow-up of nine years. We used socio-demographic factors gender, age, marital status, education, and income, but also lifestyle, diseases, and life events to predict the disability transitions over time.

Methods: We used a sample of 484 people that was randomly drawn from the municipality of Roosendaal (the Netherlands), a municipality with 78,000 inhabitants. A subset of people who completed part A of the Tilburg
Frailty Indicator (TFI) at baseline and the Groningen Activity Restriction Scale (GARS) questionnaires was used
with a nine-year follow-up. Paired Wilcoxon tests were used to compare the consecutive measurements. Socio demographic factors gender, age, marital status, education, and income, but also lifestyle, diseases, and life
events were included to predict the disability transitions over time. For the univariable and multivariable analysis of the measurements over time with the predictor variables, we used generalized estimation equations
(GEE). A p-value <0.05 was considered significant. R version 3.4.4 was used for all analyses.

Results: Of the participants, 65% were younger than 80 years, 50% were married or cohabiting, 87% reported a healthy lifestyle, and 63% had no diseases or chronic disorders. Each year, more participants changed from status
not disabled to disabled than vice versa. The GEE analyses showed that lifestyle (‘not healthy’) and diseases or chronic disorders (‘two or more’) were significant in the multivariable analysis for the disability score and only
diseases or chronic disorders (‘two or more’) was significant in the multivariable analysis for the dichotomous disability score.

Conclusions: The transition of the disability score is strongly influenced by lifestyle and diseases or disorders. This applies to a lesser extent to the dichotomous disability score. There, only diseases or disorders are an important
predictor. For health care professionals our study provides starting points for interventions focused on the prevention of worsening disability and for community-dwelling older people >= 75, the most important recommendation is: live healthy!