A cohort study to assess the impact of depression on patients with kidney disease

Abstract

Aims: This study assessed the impact of depression on mortality and quality of life of patients with kidney disease.

Material: This study was conducted at Hospital São Lucas of Pontificia Universidade Católica of Rio Grande do Sul, Porto Alegre, Brazil, with a cohort of 125 patients seen from 1996 to 2004. (mean follow-up = 77.6 months). Patients undergoing renal replacement therapy were asked to fill in the Beck Depression Inventory (BDI). At the completion of follow-up, 72 patients were alive, and 56 answered the BDI and the Medical Outcome Study Short Form General Health Survey (SF-36) to assess quality of life. Main outcome measures were mortality and quality of life.

Results: Initial analysis showed that mortality was associated with age, treatment modality--continuous ambulatory peritoneal dialysis (CAPD) or hemodialysis (hd)--and depression. When controlling for age, gender, depression, and treatment modality in a multiple regression analysis, transplantation (tx), gender and age was associated with lower mortality. However, levels of depression at the end of follow-up were strongly associated with quality of life.

Conclusions: Depression was not associated with mortality of patients with kidney disease when controlling for gender, age, and treatment modality. Transplantation was the main factor associated with lower mortality. Depression was, however, a strong predictor of quality of life. Number of depressive symptoms was directly associated with lower quality of life in most of the items of the SF-36.