Background The objective of this study is to investigate the effect of age on
care dependency risk 1 year after stroke. Two research questions are
addressed: (1) How strong is the association between age and care dependency
risk 1 year after stroke and (2) can this association be explained by burden
of disease? Methods The study is based on claims data from a German statutory
health insurance fund. The study population was drawn from all continuously
insured members with principal diagnoses of ischaemic stroke, hemorrhagic
stroke, or transient ischaemic attack in 2007 who survived for 1 year after
stroke and who were not dependent on care before their first stroke (n =
2864). Data were collected over a 1-year period. People are considered to be
dependent on care if they, due to a physical, mental or psychological illness
or disability, require substantial assistance in carrying out activities of
daily living for a period of at least 6 months. Burden of disease was assessed
by stroke subtype, history of stroke, comorbidities as well as geriatric
multimorbidity. Regression models were used for data analysis. Results 21.6 %
of patients became care dependent during the observation period. Post-stroke
care dependency risk was significantly associated with age. Relative to the
reference group (0–65 years), the odds ratio of care dependency was 11.30 (95
% CI: 7.82–16.34) in patients aged 86+ years and 5.10 (95 % CI: 3.88–6.71) in
patients aged 76–85 years. These associations were not explained by burden of
disease. On the contrary, age effects became stronger when burden of disease
was included in the regression model (by between 1.1 and 28 %). Conclusions
Our results show that age has an effect on care dependency risk that cannot be
explained by burden of disease. Thus, there must be other underlying age-
dependent factors that account for the remaining age effects (e.g., social
conditions). Further studies are needed to explore the causes of the strong
age effects observed
