Depressive symptoms, socioeconomic position and mortality in older people living with and beyond cancer.

Abstract

Evidence shows that higher depressive symptoms are associated with mortality among people living with and beyond cancer (LWBC). However, prior studies have not accounted for a wider range of potential confounders, and no study has explored whether socioeconomic position (SEP) moderates the association. This study aimed to examine the association between depressive symptoms and mortality among people LWBC, and moderation by SEP. Participants from the English Longitudinal Study of Ageing (ELSA), diagnosed with cancer and with a measure of depressive symptoms within four years following their diagnosis were included. Elevated depressive symptoms were indicated by a score of ≥3 on the 8-item Center for Epidemiologic Studies Depression Scale (CES-D). Cox regression models examined associations with all-cause mortality. Competing risk regression examined associations with cancer mortality. In 1352 people LWBC (mean age = 69.6 years), elevated depressive symptoms were associated with a 93% increased risk of all-cause mortality (95% CI: 1.52-2.45) within the first four years of follow-up, and 48% increased risk within a four to eight year follow-up (95% CI: 1.02-2.13) after multivariable adjustment. Elevated depressive symptoms were associated with a 38% increased risk of cancer mortality, but not after excluding people who died within one year after baseline assessments. There were no interactions between depressive symptoms and SEP. Elevated depressive symptoms are associated with a greater risk of all-cause mortality among people LWBC within an eight year follow-up period. Associations between depressive symptoms and cancer mortality might be due to reverse causality.