Interaction between frailty and nutritional status on mortality and long-term hospitalization in older Koreans: A retrospective analysis of data from the 2008 Survey on Health and Welfare Status of the Elderly in Korea.

OBJECTIVES

Although it is well known that nutritional deficiency influences frailty, and both nutritional status and frailty are closely related to mortality and morbidity in older people, there are no studies concerning this interaction. In this study, we evaluated whether the interaction of frailty and nutritional deficiency is additive and/or multiplicative.

METHODS

We analyzed data from 8907 individuals (≥65 years old) who took part in the 2008 Survey on Health and Welfare Status of the Elderly in Korea. We used the Cardiovascular Health Study (CHS) frailty index and the DETERMINE checklist for assessment of frailty and nutritional status, respectively. We conducted Cox regression analysis for the outcomes 'mortality' and 'mortality and long-term hospitalization risk.'

RESULTS

In the multivariate analysis for main effect model on 'mortality', the hazard ratios (HRs) of frail, high nutritional risk were 2.63 (95% CI 1.76-3.93), 1.04 (95% CI 0.78-1.38), respectively, and on 'mortality and long-term hospitalization risk' those values were 2.56 (95% CI 1.72-3.80), 1.18 (95% CI 0.88-1.58), respectively. In interaction effect model, multiplicative interaction existed between frailty and nutritional status (p < 0.001). Participants with frail X high nutritional risk had much higher HRs for 'mortality' (4.14, 95% CI 2.43-7.07) and 'mortality and long-term hospitalization risk' (4.60, 95% CI 2.74-7.72).

CONCLUSION

We found that frailty and nutritional status have a multiplicative effect on adverse outcomes in community-dwelling older adults. Nutritional status assessment in older people is important because nutritional supplementation can potentially improve both nutritional status and frailty.