Determinants of psychosocial factors amongst the oldest old: Longitudinal evidence based on the representative "survey on quality of life and subjective well-being of the very old in North Rhine-Westphalia".

Objectives: There are few studies investigating the determinants of psychosocial outcomes using data exclusively from the oldest old; and even fewer that use longitudinal data. Thus, our aim was to explore the determinants of psychosocial factors (in terms of life satisfaction, loneliness, and depressive symptoms) amongst the oldest old (also stratified by sex) based on representative, longitudinal data from Germany.

Methods/design: Data from "Survey on quality of life and subjective well-being of the very old in North Rhine-Westphalia (NRW80+)" were used. This study includes community-dwelling and institutionalized individuals aged 80 years and above (n = 1760 observations in the analytical sample) located in North Rhine-Westphalia (the most populous state in Germany). The mean age was 86.6 years (SD: 4.3 years). Established instruments were used to quantify life satisfaction, loneliness, and depressive symptoms. Linear FE regressions were used in this study to mitigate the challenge of unobserved heterogeneity. Sex-stratified regressions were also conducted.

Results: Regressions showed that the loss of a spouse was significantly associated with worsening psychosocial factors (in terms of increases in depressive symptoms and loneliness). Furthermore, regressions revealed that increases in functional impairment were significantly associated with poorer psychosocial outcomes.

Conclusions: This longitudinal study enhanced our understanding of the factors contributing to poorer psychosocial outcomes among the oldest old. Efforts to avoid or postpone functional impairment may contribute to more favorable psychosocial outcomes. Moreover, our current study underlines the importance of spousal relationships for psychosocial outcomes in the oldest age group.