BACKGROUND AND AIMS

Although total mortality is likely to be higher in elderly individuals with frailty or impaired activities of daily living (ADL), little is known about the relationships between disease-specific mortality and ADL dependency in the elderly. Therefore, we examined whether 12-year disease-specific mortality may be associated with ADL dependency in an 80-year-old population.

METHODS

In 1998, of 1,282 community-dwelling residents of Japan's Fukuoka Prefecture, 824 (64.3 %) (309 males and 515 females) participated, the remaining 458 subjects did not participate, and their deaths and causes of death were followed up for 12 years after the baseline examination. ADL dependency was determined according to the guidelines for disabled elderly from the Health, Labor, and Welfare Ministry of Japan, and ADL dependency was measured only at baseline.

RESULTS

During the 12-year follow-up, 506 died, 276 did not die, and 42 were lost. Of the 506 who died, 128 died due to cardiovascular disease, 96 to respiratory tract disease, 87 to cancer, and 51 to senility. The subjects were classified into three groups as follows: ADL-1 (independent group, n = 600), ADL-2 (almost-independent group, n = 113), and ADL-3 (dependent group, n = 93).Total-cause mortality was 2.8 times higher in ADL-3 subjects, respiratory disease mortality was 4.1 times higher in ADL-3 subjects, and senility mortality was 5.7 times higher in ADL-3 subjects than in ADL-1 subjects, after adjusting for various confounding factors. There was no association between mortality due to cancer or cardiovascular disease and ADL dependency.

CONCLUSIONS

We found an independent association between ADL dependency and mortality due to all causes, respiratory disease or senility, but no association with mortality due to cancer or cardiovascular disease. These findings suggest that improving ADL dependency may reduce all mortality and mortality due to respiratory disease or senility.