Objective: To study the impact of various risk factors on survival time in a cohort of elderly Australians.
Design, setting and participants: A longitudinal, prospective cohort study conducted in Dubbo, NSW. Participants were men and women aged 60 years or over living in the community, first assessed in 1988–1989 and followed for 15 years.
Main outcome measures: Mortality rates; risk factors; survival times.
Results: There were 668 deaths in 1233 men (54%) and 625 deaths in 1572 women (40%). Coronary heart disease was the major cause of death, rates being higher in men than women until age group 80+ years; stroke death rates were similar in both sexes; cancer and respiratory death rates were higher in men than women across all ages. In a proportional hazards model, the independent predictors of mortality were cigarette smoking, diabetes, very high blood pressure (BP), impaired peak expiratory flow (PEF), physical disability, and zero intake of alcohol. Over 15 years, the average reductions in survival time associated with various risk factors, in men and women respectively, were smoking, 22 and 15 months; diabetes, 18 and 18 months; very high BP, 16 and 9 months; impaired PEF, 14 and 17 months; physical disability, 16 and 12 months; zero alcohol intake, 9 and 5 months. Combinations of selected risk factors were associated with a multiplier effect.
Conclusion: The reduction in survival time in elderly citizens demonstrated in the presence of smoking, diabetes and hypertension highlights a potential benefit to healthy ageing to be gained from prevention and intervention.
- 1. Kaplan A, Seeman TE, Cohen RD, et al. Mortality among the elderly in the Alameda County Study: behavioural and demographic risk factors. Am J Public Health 1987; 77: 307-312.
- 2. Kleinman JC, Donahue RP, Harris MI, et al. Mortality among diabetics in a national sample. Am J Epidemiol 1988; 128: 389-401.
- 3. Glynn RJ, Field TS, Rosner B, et al. Evidence of a positive linear relation between blood pressure and mortality in elderly people. Lancet 1995; 345: 825-829.
- 4. Idler EL, Kasl SV, Lemke JH. Self-evaluated health and mortality among the elderly in New Haven, Connecticut, and Iowa and Washington Counties, Iowa, 1982-1986. Am J Epidemiol 1990; 131: 91-103.
- 5. McCallum J, Shadbolt B, Wang D. Self-rated health and survival: a 7-year follow-up study of Australian elderly. Am J Public Health 1994; 84: 1100-1105.
- 6. Seeman TE, Kaplan GA, Knudsen L, et al. Social network ties and mortality among the elderly in the Alameda County Study. Am J Epidemiol 1987; 126: 714-723.
- 7. Simons LA, McCallum J, Simons J, et al. The Dubbo Study: an Australian prospective community study of the health of elderly. Aust N Z J Med 1990; 20: 783-789.
- 8. Simons LA, McCallum J, Friedlander Y, et al. Dubbo Study of the elderly: sociological and cardiovascular risk factors at entry. Aust N Z J Med 1991; 21: 701-709.
- 9. The Dubbo Study. Available at: www.dubbostudy.org (accessed Jan 2005).
- 10. Radlof LS. The CES-D Scale: a self-report depression scale for research in the general population. Appl Psychol Measurement 1977; 1: 385-401.
- 11. SPSS. Statistical package for the social sciences. Version 12.0.1. Chicago, Ill: SPSS Inc, 2004.
- 12. United Nations. World population prospects 1990. New York: United Nations, 1991.
- 13. Mathers C, Vos T, Stevenson C. The burden of disease and injury in Australia – summary report. Canberra: Australian Institute of Health and Welfare, 1999.
- 14. LaCroix AZ, Lang J, Scherr PA, et al. Smoking and mortality among older men and women in three communities. N Engl J Med 1991; 324: 1619-1625.
- 15. Hedblad B, Ogren M, Isacsson SO, Janzon L. Reduced cardiovascular mortality risk in male smokers who are physically active. Results from a 25-year follow-up of the prospective population study men born in 1914. Arch Intern Med 1997; 157: 893-899.
- 16. Kannel WB, Hubert H, Lew EA. Vital capacity as a predictor of cardiovascular disease: the Framingham Study. Am Heart J 1983; 105: 311-315.
- 17. Scherr PA, LaCroix AZ, Wallace RB, et al. Light to moderate alcohol consumption and mortality in the elderly. J Am Geriatr Soc 1992; 40: 651-657.
- 18. Simons LA, McCallum J, Friedlander Y, et al. Moderate alcohol intake is associated with survival in the elderly: the Dubbo Study. Med J Aust 2000; 172: 121-124. <MJA full text>
- 19. Holman CDJ, English DR, Milne E, Winter MG. Meta-analysis of alcohol and all-cause mortality: a validation of NHMRC recommendations. Med J Aust 1996; 164: 141-145.
- 20. Simons LA, Simons J, Friedlander Y, McCallum J. Risk factors for acute myocardial infarction in the elderly (The Dubbo Study). Am J Cardiol 2002; 89: 16-19.
- 21. Fraser GE, Shavlik DJ. Ten years of life: is it a matter of choice? Arch Intern Med 2001; 161: 1645-1652.
- 22. Ferrucci L, Izmirlian G, Leveille S, et al. Smoking, physical activity, and life expectancy. Am J Epidemiol 1999; 149: 645-653.
- 23. Woo J, Ho SC, Yu AL. Lifestyle factors and health outcomes in elderly Hong Kong chinese aged 70 years and over. Gerontology 2002; 48: 234-240.
- 24. Mozaffarian D, Fried LP, Burke GL, et al. Lifestyles of older adults: can we influence cardiovascular risk in older adults? Am J Geriatr Cardiol 2004; 13: 153-160.
- 25. Chobanian AV, Bakris GL, Black HR, et al. Seventh report of the Joint National Committee on prevention, detection, evaluation and treatment of high blood pressure. Hypertension 2003; 42: 1206-1252.
- 26. Oxford Centre for Diabetes, Endocrinology and Metabolism. UK Prospective Diabetes Study. Available at: www.dtu.ox.ac.uk/ukpds (accessed Jan 2005).
- 27. Colhoun HM, Betteridge DJ, Durrington PN, et al. Primary prevention of cardiovascular disease with atorvastatin in type 2 diabetes in the Collaborative Atorvastatin Diabetes Study (CARDS): multicentre randomised placebo-controlled trial. Lancet 2004; 364: 685-696.
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