Fatores psicossociais e funcionalidade no envelhecimento: evidências da coorte de Bambuí e do English Longitudinal Study of Ageing

Abstract

Introduction: World population projections showed that the number of people at the age of 65 and above will grow from 524 millions in 2010 to nearly 1.5 billion in 2050 and the ageing is associated with disability. One of the key public health concerns is the elderly functioning maintenance and improvement and more studies on this topic are necessary. The identification of social and biological preditors related to the disability onset may potentially contribute for identifying vulnerable groups. This could enhance both prevention and engagement of target groups in early rehabilitation. Among the social preditors, social epidemiology shows that psychosocial factors have a striking impact in populations health.Objectives: This thesis aimed to explore the functioning and its association with psychosocial factors among older Brazilian and English adults, taking into account modern statistic models. Addictionally, we explored variables that could modificate this association, such as socioeconomic inequalities, sex and emotional support. Material and methods: We used data from the Bambui Cohort Study of Ageing (longitudinally) and the English Longitudinal Study of Ageing (cross-sectionally). Functioning was measured by difficultility in carrying out basic activities of daily living (ADL) and instrumental activities of daily living (IADL). The statistical analysis was based on modern statistical models to refine the results interpretation: (1) we used the competing-risks regression, taking into account that death is an informative censoring when we estimate the disability risk; (2), we used the multinomial logistic regression using the interaction between disability and socioeconomic condiction as the outcome variable.Results: In Brazil, the disability incidence rate in 15 years was 359 per 1,000 personyears, 347 people died and 96 were lost in follow-up. At baseline, mean age was 68.6 ± 6.7 years, 23.1% showed minor depressive (mental) symptoms, 10.4% major depressive (mental) symptoms and 40.5% reported low emotional support from the closest person. Persons with low emotional support from the closest person were at significant increased risk for incident ADL disability, after adjustments. The same pattern was observed for major depressive (mental) symptoms. After conjugating both in a model to assess modification effect, we did not find any significant interaction. In England, mean age was 66.0 ± 8.4 years, 10.2% showed depressive symptoms and 31.3% reported low social support from friends, family or children. The multinomial logistic regression showed that wealth modifies the association between psichosocial factors and functioning: the poorest, the stronger the association between depressive symptoms and functioning, in both sex. Adictionally, among men, those with ADL/IADL disability and the poorest showed higher odds of having no weekly contact with friends, familiy or children, and not living with partner. Among women, those with disability and the poorest showed higher odds of loneliness. Conclusions: Both in England and Brazil, cross-sectionally and very long term, respectively, social support and depressive symptoms are related to functioning among older adults. Interventions that aim to enhance social contacts and support and treatment or prevention of depressive symptoms may potentially decrease negative aspects of disability by psychological pathways. Moreover, the target population are the poorest. Besisdes material causes, we showed that social environment, as suggested by psychosocial theory, is also related to health inequalities.