The relationship between symptoms, depression, and quality of life in peritoneal dialysis patients

Measurement of patient outcome by mental and social indexes such as quality of life (QOL) in addition to survival is a growing trend. We examined the feasibility of using a single global QOL question in peritoneal dialysis (PD) patients. We also examined the relationship that QOL has with uremic symptoms and depression in these patients. During a clinic visit, each PD patient completed a single-question QOL measure (0-10 scale, 10 being best). Patients' symptoms were assessed using a 10-symptom checklist, with each symptom scored on a Likert scale of 0 (none) to 5 (severe). We evaluated for depression using two questions from the Primary Care Evaluation of Mental Disorders. Serum albumin, hemoglobin, and phosphorus were obtained, but only phosphorus was associated with QOL on univariate analysis (p = 0.05) and therefore included in the multivariate model. Results (checklist score, depression, phosphorus, age, diabetes, and race) were analyzed using a sequential multivariate analysis with QOL as the dependent variable. The study population consisted of 64 PD patients [mean age: 47 +/- 16 years; 25% black; 23% with diabetes; 31% incident (< or =3 months)]. The median score on the single QOL question was 7 (range: 1-10). Patients scored a median of 9 (range: 0-31) out of 50 on the total symptom checklist. Among responding patients, 34% answered yes to at least one depression question. The sequential incremental r2 values associated with a poorer QOL were higher checklist score (r2 = 0.16, p < 0.02), presence of depression (r2 = 0.13, p < 0.00002), younger age (r2 = 0.06, p < 0.03), and presence of diabetes (r2 = 0.04, p < 0.05). In this model, PO4 and race were nonsignificant. Total r2 in the model was 0.48. The single measure of QOL, the checklist score, and the depression screening score were simple and easy to obtain during a routine clinic visit. We conclude that physical symptoms and depression are strongly associated with a simple single measure of QOL. The extent to which symptoms and depression can be improved by clinical intervention, and the subsequent effect on quality of life and survival, should be examined in longitudinal studies.