During the final decade of life, patients experienced steeper declines in physical, cognitive, and psychological functioning compared with survivors, with physical functioning showing the greatest deterioration.
Investigators analyzed harmonized longitudinal data from the US Health and Retirement Study, the China Health and Retirement Longitudinal Study, and the Survey of Health, Ageing and Retirement in Europe involving 79,305 adults aged 45 years or older from 17 countries. During the 10 years of follow-up, 12,135 of the participants died. Physical functioning was assessed using activities of daily living, cognitive functioning tests, and psychological functioning using validated depressive symptom scales. The investigators examined the trajectory of the three functional domains during the decade preceding mortality. Additional analyses identified multidomain co-decline patterns and examined whether socioeconomic status was associated with trajectory membership.
Compared with survivors, decedents had poorer physical, cognitive, and psychological functioning and experienced faster declines across all three domains. Physical functioning declined more rapidly compared with cognitive or psychological functioning, and deterioration accelerated as mortality approached, supporting the presence of terminal decline across multiple domains.
Among the decedents included in the multidomain trajectory analysis, the investigators identified four distinct patterns of decline. Nearly 44% of them maintained relatively high functioning with only mild declines across all domains. About 31% had relatively preserved physical and psychological functioning but persistently lower cognitive functioning. Another 14% experienced declining physical functioning accompanied by worsening cognitive and psychological functioning, while 11% experienced rapidly declining physical functioning together with low and worsening cognitive and psychological functioning.
Higher socioeconomic status was associated with a lower likelihood of associating with the most unfavorable trajectory. Compared with participants in the lowest socioeconomic group, those in the highest group had approximately 93% lower odds of experiencing rapid physical decline accompanied by worsening cognitive and psychological functioning. Educational attainment showed a stronger association with favorable trajectories compared with household income. The associations remained consistent across analyses stratified by age and sex.
Subgroup analyses showed that differences in physical functioning between decedents and survivors were more pronounced among female participants, older participants, and those with lower educational attainment. Differences in cognitive functioning prior to mortality were greater among female participants, whereas poorer psychological functioning prior to mortality was more evident among male participants. Sensitivity analyses produced similar findings.
The investigators acknowledged several limitations. Physical and psychological functioning relied on self-reported assessments, and functional measures differed across the cohorts, requiring statistical harmonization. Exact mortality dates were unavailable for some participants and were imputed. In addition, assessments conducted every 2 to 3 years may not have captured finer changes near the end of life, and the multidomain trajectory analysis included only decedents with at least three repeated measurements, which may limit the generalizability of the identified trajectory patterns.
The findings suggested that physical, cognitive, and psychological functioning often decline concurrently during the final decade of life. The investigators stated that socioeconomic status may be associated with the likelihood of experiencing more unfavorable multidomain patterns of decline.
“Early screening to identify overall functional impairment, and strategies to reduce accelerated functional decline, should start before old age. Identifying co-decline patterns, particularly among socioeconomically disadvantaged groups, may help inform targeted strategies to promote healthy longevity and reduce end-of-life health inequalities,” wrote lead study author Junjie Lin, of the School of Public Health at The Second Affiliated Hospital at the Zhejiang University School of Medicine, and colleagues.
The study authors reported no competing interests.
Source: BMC Medicine