Psychosocial predictors of survival in end-stage renal disease

Several psychosocial variables were investigated as predictors of 4-year survival in a sample of 97 end-stage renal disease (ESRD) patients undergoing treatment by hemodialysis, continuous ambulatory peritoneal dialysis, or renal transplantation. Hypothesized psychosocial predictors included depression, mood disturbance, life happiness, affect, pessimism, self-esteem, knowledge of renal disease and its treatment, perceived control over important life domains, perceived intrusiveness of ESRD into important life domains, illness-related concerns, difficulties in daily activities, number of regular leisure activities, somatic symptoms of distress, social networks, recent negative life events, and defensive response styles. Methodological controls were incorporated to test the prognostic significance of these variables and included a) exclusion of deaths attributable to "unnatural" causes; b) multivariate statistical controls for physical and demographic determinants of survival; c) widely used standardized psychosocial instruments; and d) temporally aggregated psychosocial measurements to enhance reliability. Hierarchical multiple regression analyses identified four variables as significant and independent predictors of increased survival times in ESRD: a) comparatively fewer serious nonrenal comorbid illnesses; b) younger age; c) regular involvement in an increased number of leisure activities; and d) overall life happiness described as "an even mixture of unhappiness and happiness" (as compared with "very happy"). However, no evidence was obtained to support the hypothesis that increased depressive symptoms and/or moods contribute to compromised survival in ESRD.