Exploring the influence of depressive symptoms on physical disability: a cohort study of elderly in Beijing, China.
OBJECTIVE
This study examined the influence of depressive symptoms on the prevalence of physical disability in a cohort study of Beijing elderly (1992--2000) and analyses the role of some confounding variables in this relationship.


METHODS
A cohort of 1828 elderly aged 55 and older who were initially free of any physical disability was followed up for 8 years. Baseline depression was assessed by the Center for Epidemiological Studies Depression Scale. Disability on activities of daily living (BADL and IADL) was measured in 1994, 1997, and 2000 respectively.


RESULTS
The cumulative percentages of persons who developed BADL disability and IADL disability during each follow-up interview was significantly greater among depressed than non-depressed individuals. Compare with the 1525 non-depressed individuals, the 303 depressed individuals had a relative risk (95% confidence interval) of 2.52 (2.02, 4.82) for BADL disability and 4.98 (2.46, 10.09) for IADL disability, respectively. Although adjustment for confounding factors reduced the risk to 2.20 (1.33, 3.62) and 4.29 (2.08, 8.86), the detrimental effect of depression on disability remained significant. The items of IADL which connected physical activity had higher impairment among depressed individuals.


CONCLUSIONS
Depression in elderly persons may increase the risk for prevalent disability. It is very important for elders to prevent and reduce depression for improving the quality of their life and physical function.
Department of Epidemiology and Medical Statistics, School of Medicine, Beijing Union Medical College, Beijing, PR China. Jingmeijiang238@hotmail.com
Jingmei
J
Jiang
Zhe
Z
Tang
Makoto
M
Futatsuka
Konglai
K
Zhang
D000368:Aged; D000369:Aged, 80 and over; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D015986:Confounding Factors, Epidemiologic; D003863:Depression / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D006233:Persons with Disabilities / Q000706:statistics & numerical data*; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors