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Predictors of Mortality in 2,249 Nonagenarians—The Danish 1905-Cohort Survey


  • This study and the activities of the Danish Center for Demographic Research are supported by a grant from the Danish National Research Foundation and National Institute on Aging (Grant P01-AG08671).

Address correspondence to Kaare Christensen, MD, PhD, Epidemiology, Institute of Public Health and Aging Research Center, University of Southern Denmark, Sdr. Boulevard 23 A, DK-5000 Odense C, Denmark. E-mail:


Objectives: To elucidate whether well-known predictions of mortality are reduced or even reversed, or whether mortality is a stochastic process in the oldest old.

Design: A multidimensional survey of the Danish 1905 cohort conducted in 1998 with follow-up of vital status after 15 months.

Setting: Denmark.

Participants: All Danes born in 1905, irrespective of physical and mental status were approached. Two thousand two hundred sixty-two persons of 3,600 participated in this survey.

Measurements: Professional interviewers collected data concerning sociodemographic factors, smoking, alcohol consumption, body mass index, physical and cognitive performance, and health during a visit at the participant's residency. Cox regression models were used to evaluate predictors of mortality.

Results: Five hundred seventy-nine (25.7%) of the 2,249 participants eligible for the analysis died during the 15 months follow-up. Multivariate analyses showed that marital status, education, smoking, obesity, consumption of alcohol, and number of self-reported diseases were not associated with mortality. Disability and cognitive impairment were significant risk factors in men and women. In addition poor self-rated health was associated with an increase in mortality in women.

Conclusion: In the oldest old, several known predictors of mortality, such as sociodemographic factors, smoking, and obesity, have lost their importance, but a high disability level, poor physical and cognitive performance, and self-rated health (women only), predict mortality, which shows that mortality in the oldest old is not a stochastic process.