Health Trajectories of Independent and Dependent Centenarians: A Swedish Nationwide Cohort Study.

Background and objectives: Although a large proportion of centenarians depend on assistance, many still live at home, independently or with a little formal long-term care. It is of interest to explore this group further and compare them to dependent centenarians.

Research design and methods: This register-based cohort included the entire Swedish centenarian population between 2020 and 2022. Centenarians were classified into two groups: those independent of formal long-term care and those dependent on such care. Disease trajectories were observed in historical data from age 67 and onwards and described for myocardial infarction, stroke, hip fracture, dementia, diabetes, and different cancer diagnoses, as well as hospitalizations and the number of prescribed drugs.

Results: Of the 4,277 centenarians, 36% were independent. Compared with dependent centenarians, independent centenarians had lower incidences of stroke and dementia after age 85 and a lower incidence of hip fracture from age 75. They were less often hospitalized and had lower levels of polypharmacy. In regression analysis, women, stroke, hip fracture, dementia, and more prescribed drugs were associated with an increased risk of being dependent at age 100, while being married was associated with a reduced risk.

Discussion and implications: The health differences between independent and dependent centenarians appeared mainly after life expectancy was exceeded. After this age, differences in incidences of hip fracture, stroke, and dementia became apparent between the groups. This finding underscores that these diseases affect care needs in very old age and that avoiding them is linked to a more independent life as a centenarian.