July 10, 2008
Prevalence of Chronic Diseases and Multimorbidity Among the Elderly Population in Sweden
By Marengoni, Alessandra Winblad, Bengt; Karp, Anita; Fratiglioni, Laura
We explored the role of age, gender, and socioeconomic status in the occurrence of chronic diseases and multimorbidity in 1099 elderly participants in the Kungsholmen Project. Cardiovascular and mental diseases were the most common chronic disorders. Of the participants, 55% had multimorbidity. Advanced age, female gender, and lower education were independently associated with a more than 50% increased risk for multimorbidity. Multimorbidity is the most common clinical picture of the elderly and may be increased by unhealthy behaviors linked to education. (Am J Public Health. 2008;98:1198-1200. doi:10.2105/AJPH.2007.121137) Because of the aging of the population1 and the association of chronic diseases with advanced age,2 "multimorbidity," defined as coexistence of 2 or more chronic diseases, is expected to become a common problem in elderly populations. Previous studies have reported multimorbidity prevalence rates ranging from 40% to 80%; these rates are higher among women than among men.3-5 Few studies have evaluated the distribution of chronic conditions and multimorbidity by socioeconomic status (SES).6,7 Recently, Chandola et al.8 showed that physical health deteriorated more rapidly with age among persons from the lowest occupational grade. We used clinical data from the Kungsholmen Project in Stockholm, Sweden (1987-2000)9 to explore the role of age, gender, and SES in the occurrence of chronic diseases and multimorbidity in the elderly population in Sweden.
The study population consisted of participants in the first follow-up (n=1099) of the Kungsholmen Project, during which physicians performed a complete clinical examination on all persons. The diagnoses were based on clinical assessment, medical history (from the Stockholm Inpatient Register that records discharge diagnoses from Stockholm, Sweden, hospitals), laboratory data, and current drug use. A disease was classified as chronic if it was permanent, caused by nonreversible pathological alteration, or required rehabilitation or a long period of care.10
The International Classification of Diseases, Ninth Revision (ICD- 9),11 was used for all diagnoses, with some exceptions. Deafness was defined as being unable to hear the interviewer's voice, and visual impairment was defined as being blind or almost blind. Major depression was diagnosed by a psychiatrist according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV ), criteria12; Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition (DSM-III-R), criteria were used to diagnose dementia13; and diagnosis of anemia followed the World Health Organization criteria.14 Multimorbidity was defined as any co- occurrence of 2 or more chronic conditions (among the 30 detected) in the same individual, whether coincidental or not.15 SES was evaluated according to education (years of schooling) and the main life occupation in a subgroup of 770 participants.16
The study population were aged 77 to 100 (mean=84.6 years), and 77% were women. Nearly half of the participants had high education levels and worked in white-collar occupations (data supplement to the online version of this article at http://www.ajph.org).
Hypertension, dementia, and heart failure were the most common disorders, with a prevalence of 38%, 21%, and 18%, respectively, whereas all other diseases were less frequent (15%; data supplement to the online version of this article at http://www.ajph.org). Figure 1 shows prevalence figures, by age, of chronic diseases, grouped according to the ICD-9 classification. Cardiovascular disease prevalence did not differ by age or gender, whereas a higher proportion of mental disorders was found among the oldest-old (i.e., =85 years) than among the younger-old persons (i.e., 77-84 years; 36.4% vs 17.9%; P
Thirty percent of the population had only 1 disease, whereas 55% had multimorbidity. The median number of diseases among persons with multimorbidity was 3, ranging from 2 to 7. Multimorbidity prevalence figures are reported in Table 1. In multivariate logistic regression analyses, age, gender, and education were independently associated with multimorbidity (Table 1).
Occupation-based SES showed a crude association with multimorbidity (odds ratio [OR]=1.5; 95% confidence interval [CI]= 1.0, 2.3) but not when adjusted for sociodemographic variables (Table 1). Because of the high correlation between education and SES, we stratified education and occupation-based SES into 4 groups. Low education level showed a strong association with multimorbidity independent of high or low occupation-based SES (OR=1.9; 95% CI=1.1, 3.3 and OR=1.7; 95% CI=1.0, 2.7, respectively).
In line with previous reports,17,18 cardiovascular diseases and mental conditions emerged as the most common chronic disorders. Although the prevalence of cardiovascular diseases did not differ by age or gender, the prevalence of mental conditions increased with age, mostly because of the high number of oldest-old women affected by dementia.
In agreement with previous reports,19,20 the prevalence of multimorbidity was as high as 55%; significantly higher prevalence rates were found among the oldest-old (P
1. Centers for Disease Control and Prevention. Public health and aging: trends in aging-United States and worldwide. JAMA. 2003;289:1371-1373.
2. Crimmins EM. Trends in the health of the elderly. Annu Rev Public Health. 2004;25:79-98.
3. van Weel C. Chronic diseases in general practice: the longitudinal dimension. Eur J Gen Pract. 1996;2: 17-21.
4. Fried LP, Bandeen-Roche K, Kasper JD, Guralnik JM. Association of comorbidity with disability in older women: the Women's Health and Aging Study. J Clin Epidemiol. 1999;52:27-37.
5. van den Akker M, Buntinx F, Metsemakers JF, Roos S, Knottnerus JA. Multimorbidity in general practice: prevalence, incidence, and determinants of co-occurring chronic and recurrent diseases. J Clin Epidemiol. 1998;51:367-375.
6. House JS, Kessler RC, Hergoz AR. Age, socioeconomic status, and health. Milbank Q. 1990;68: 383-411.
7. van den Akker M, Buntinx F, Metsemakers JF, Knottnerus JA. Marginal impact of psychosocial factors on multimorbidity: results of an explorative nested case-control study. Soc Sci Med. 2000;50:1679-1693.
8. Chandola T, Ferrie J, Sacker A, Marmot M. Social inequalities in self reported health in early old age: follow-up of prospective cohort study. BMJ. 2007;334: 990-997.
9. Fratiglioni L, Viitanen M, Backman L, Sandman PO, Winblad B. Occurrence of dementia in advanced age: the study design of the Kungsholmen Project. Neuroepidemiology. 1992;11(suppl 1):29-36.
10. Timmreck TC, Cole GE, James G, Butterworth DD. Health education and health promotion: a look at the jungle of supportive fields, philosophies and theoretical foundations. Health Educ. 1987;18:23-28.
11. International Classification of Diseases, Injuries, and Causes of Death, Ninth Revision. Geneva, Switzerland: World Health Organization; 1987.
12. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Washington, DC: American Psychiatric Association; 1994:133- 158.
13. Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition. Washington, DC: American Psychiatric Association; 1987:97-163.
14. Nutritional Anemias. Report of a WHO Scientific Group. Geneva, Switzerland: World Health Organization; 1968. Technical Report Series No. 405.
15. van den Akker M, Buntinx F, Knottnerus JA. Comorbidity or multimorbidity: what's in a name? A review of literature. Eur J Gen Pract. 1996;2:65-70.
16. Karp A, Kareholt I, Qiu C, Bellander T, Winblad B, Fratiglioni L. Relation of education and occupationbased socioeconomic status to incident Alzheimer's disease. Am J Epidemiol. 2004;159:175-183.
17. Haan MN, Selby JV, Rice DP, et al. Trends in cardiovascular disease incidence and survival in the elderly. Ann Epidemiol. 1996;6:348-356. 18. Fratiglioni L, Launer LJ, Andersen K, et al. Incidence of dementia and major subtypes in Europe: a collaborative study of population-based cohorts. Neurologic Diseases in the Elderly Research Group. Neurology. 2000;54(11 suppl 5):S10-S15.
19. Wolff JL, Starfield B, Anderson G. Prevalence, expenditures, and complications of multiple chronic conditions in the elderly. Arch Intern Med. 2002;162: 2269-2276.
20. Hoffman C, Rice D, Sung HY. Persons with chronic conditions: their prevalence and costs. JAMA. 1996;276:1473-1479.
21. Winkleby MA, Jatulis DE, Frank E, Fortmann SP. Socioeconomic status and health: how education, income, and occupation contribute to risk factors for cardiovascular disease. Am J Public Health. 1992;82:
Alessandra Marengoni, MD, PhD, Bengt Winblad, MD, PhD, Anita Karp, PhD, and Laura Fratiglioni, MD, PhD
About the Authors
The authors are with the Aging Research Center, Karolinska Institutet, Stockholm, Sweden, and Stockholm Gerontology Research Center, Stockholm. Alessandra Marengoni is also with the Department of Medical and Surgery Sciences, University of Brescia, Italy.
Requests for reprints should be sent to Alessandra Marengoni, MD, I Medicina, Spedali Civili. Piazzale Spedali Civili 1, 25121 Brescia, Italy (e-mail: [email protected]).
This brief was accepted October 9, 2007.
A. Marengoni performed the analyses and wrote the brief. B. Winblad supervised the study. A. Karp supervised the socioeconomic aspects of the study. L. Fratiglioni originated the study and supervised the analyses.
This study has been supported by C. M. Lerici Foundation and the Swedish Council for Working Life and Social Research.
Human Participant Protection
The research follows the guidelines of the Swedish Council for Research in the Humanities and Social Sciences, and the ethics committee of the Karolinska Institutet approved the study.
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