Long-term mortality assessment using biological measures among elderly people. Ten-year follow-up of 597 healthy elderly subjects in Taiwan.
BACKGROUND
Identifying biological measures that are predictive of mortality for elderly people aged over 65 years has not been fully elucidated in oriental studies.


OBJECTIVE
The associations between these biological measures and long-term mortality were therefore investigated, and classifications for risk of death were developed among Taiwanese elderly people


METHODS
Data used in this study were derived from a total of 597 apparently healthy subjects aged over 65 years identified from a nationwide survey that was conducted between 1989 and 1991 in Taiwan. Each participant received a physical examination and a wide range of biological measures. These 597 apparently healthy subjects were followed to 31 December 1999 to determine the cause of death. The grouping technique using factor analysis was first used to aggregate similar characteristics of biological measures into reduced components. Risk of death for each subject was classified into four groups: good (A), fair (B), modest (C) and poor (D). Hazard ratios for groups B, C, D against A were calculated.


RESULTS
The overall 10-year survival rate was 72% [95% confidence interval (CI) 68-76%]. The adjusted hazard ratios for all-cause death in high and mid-level categories of haematological components versus the lowest group were 0.51 (95% CI 0.33-0.80) and 0.56 (95% CI 0.37-0.85), respectively. Group D had a 6-fold risk of death as compared with group A (relative risk = 6.34, 95% CI 3.85-10.52). The corresponding figures were 2.48 (95% CI 1.43-4.29) and 1.60 (95% CI 2.88-6.89) for groups B and C, respectively.


CONCLUSIONS
The relationships of biological measures to long-term mortality were elucidated. Information on classification for risk of death may be helpful for elderly people to pay attention to their health status after receiving a health check-up.
Wu
Tzy-Haw
TH
Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
Lee
Ti-Kai
TK
Yen
Ming-Fang
MF
Tung
Tao-Hsin
TH
Chen
Tony Hsiu-Hsi
TH
D000368:Aged / Q000706:statistics & numerical data*; D015415:Biomarkers; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D008297:Male; D009026:Mortality; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D012016:Reference Values; D018570:Risk Assessment / Q000379:methods; D015996:Survival Rate; D013624:Taiwan / Q000453:epidemiology; D013995:Time
D015415:Biomarkers