Prevalence and Risk Factors of Dementia and Depression in the Elderly

Suh, Guk Hee; Kim, Jang Kyu; Yeon, Byeong Kil; Park, Sue Kyung; Yoo, Keun Young; Yang, Byung Kook; Kim, Yong Sik; Cho, Maeng Je

Abstract

An epidemiological survey was conducted to estimate the prevalence of and identify the risk factors of dementia and depression in the elderly between December 1997 and August 1998 in Yonchon County, Korea. A total of 1,037 elderly aged 65 years and over underwent a two phase diagnositc procedure. Multiple stage, random cluster sampling method was used to select the subjects. Response rate was 85.4%. For the 1st stage screening survey, the Korean Psychogeriatric Assessment Scale was used as a primary screening tool, which had already been standardized in Korea, and functioning and social support were assessed by ADL, IADL and APGAR. At the 2nd stage, diagnoses were confirmed according to the DSM-III-R. And several other scales were used as supporting information for differential diagnoses and for evaluating severity. 1) Age-sex adjusted prevalence(%)[95% C.I.] of dementia was 6.83[6.12-7.54](male 6.34[5.29-7.40]female 7.09[6.14-8.04]). Prevalence of the dementia of the Alzheimer's type was 4.17[3.61-4.74](male 2.42[1.76-3.08], female 5.31[4.48-6.14]) and that of the vascular dementia was 2.38 [1.95-2.81](male 3.46[2.67-4.25], female 1.63[1.16-2.10]). 2) Age-sex adjusted prevalence(%)[95% C.I.] of depressive disorder was 10.99 [10.11-11.87] (male 7.59[6.44-8.73], female 13.46[12.20-14.73]). Among depressive disorders, prevalence(%) [95% C.I.] of major depressive disorder was 7.50[6.76-8.26](male 4.42[3.54-5.31], female 9.78 [8.68-10.88]), that of dysthymic disorder was 2.02[1.62-2.42](male 1.37[0.86-1.87], female 2.46 [1.88-3.03]) and that of depressive disorder NOS was 1.49[1.15-1.83](male 1.85[1.47-2.23], female 1.28[0.96-1.60]). 3) Five statistically significant risk factors of the dementia of the Alzheimer's type were identified: age over 85(O.R.=10.27), illiteracy(O.R.=4.01), alcohol abuse(O.R.=2.98), smoking[030(O.R.=4.60)] and family history of dementia(O.R.=4.85). 4) Three statistically significant risk factors of the vascular dementia were identified: illiteracy (O.R.=3.78), history of CVA(O.R.=26.76) and smoking over 40 pack year (O.R.=11.15). 5) Three statistically significant risk factors of the depressive disorder were identified: age between 75 and 79(O.R.=2.87), past history of CVA(O.R.=3.33) and family history of depressive disorder (O.R.=7.16).