What the study found
Activities of daily living (ADL) disability and instrumental activities of daily living (IADL) disability were both associated with higher long-term all-cause mortality across five cohorts of middle-aged and older adults.
Why the authors say this matters
The authors conclude that these findings underscore health inequities faced by people with disabilities and highlight the need for health systems to better include and serve people with disabilities in policies and services.
What the researchers tested
The researchers conducted a pooled multi-cohort study using harmonized data from five longitudinal studies: HRS, CHARLS, SHARE, ELSA, and MHAS. They used Cox proportional hazards models to examine associations with all-cause mortality, assessed additive interaction between ADL and IADL disabilities, and carried out exploratory mediation analyses involving chronic conditions and depression.
What worked and what didn't
In pooled analyses, compared with no disability, mortality risk was higher for one ADL disability item and higher still for two or more ADL disability items. The same pattern was seen for IADL disability, with larger hazard ratios for two or more items than for one item. Exploratory mediation analyses suggested that chronic conditions may contribute in some cohorts, but this was not evident in CHARLS, while depression showed potential contributions across cohorts; additive interaction between ADL and IADL was statistically significant in CHARLS and MHAS.
What to keep in mind
The study is based on five specific longitudinal cohorts, so the findings apply to the populations included there. The abstract describes exploratory mediation analyses and time-dependent models, but it does not provide a detailed list of limitations beyond the cohort-specific differences noted.
Key points
- ADL and IADL disabilities were associated with higher all-cause mortality across five cohorts.
- In pooled analyses, mortality risk increased with more ADL disability items and with more IADL disability items.
- Exploratory mediation analyses suggested possible contributions from chronic conditions in some cohorts and from depression across cohorts.
- Additive interaction between ADL and IADL was statistically significant in CHARLS and MHAS.
- The authors say the findings highlight health inequities and the need for better inclusion of people with disabilities in health systems.
Disclosure
- Research title:
- Disability in daily activities linked to higher mortality
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