Measuring disease severity in patients with end-stage renal disease: validity of the Craven et al. ESRD Severity Index.

The validity of a recently developed measure of disease severity, the End-stage Renal Disease Severity Index (Craven et al. 1991) was examined in haemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients (total N = 82). Scores on the ESRD Severity Index were compared with three commonly identified components of disease severity: physiological indices of severity, functional status, and psychological burden of illness. For the entire group of subjects, scores on the ESRD Severity Index were negatively associated with functional ability and positively related to physiological severity. ESRD Severity Index scores showed a weaker relationship with psychological burden of illness which depended in part on treatment mode. Disease severity scores were positively related to depression in CAPD patients but not in HD patients. These findings suggest that the ESRD Severity Index is a valuable research tool with construct validity.