Predictive factors for institutionalization of the elderly: a case-control study

To identify predictive indicators of institutionalization of the elderly.

A case-control study was carried out with 991 elderly individuals in the city of Pelotas, (Southern Brazil), from 2007 to 2008. The cases of institutionalized elderly adults (n = 393) were detected using a census of all long-stay institutions for the elderly in the city. The population controls (n = 598) were randomly selected using a comprehensive health survey. Pearson's chi-square test and linear trends were used to compare groups in the crude analysis; and the binary logistic regression model of the adjusted analysis, with the effects expressed as odds ratios.

Institutionalization was more frequent in females (OR = 1.96, 95%CI 1.31, 2.95). Elderly with advanced age (OR = 3.23 and OR = 9.56 for age groups 70-79 and > 80 years, respectively), those who lived without a partner (single, divorced or widowed), and those who had no formal schooling or had a functional disability preventing them from performing basic activities for daily living were more likely to be institutionalized. An inverse trend between the incidence of elderly institutionalization and the level of physical activity was observed, where somewhat active and inactive subjects were more likely to be institutionalized (OR = 1.71 and OR = 4.73, respectively).

Of the factors examined, age > 80 years, living without a partner and being physically inactive were the indicators most strongly associated with institutionalization. The encouragement of informal care through cultural and educational activities focused on the role of the family in caring for the elderly can prevent the institutionalization of these individuals.