Validity and Reliability of the SF-36 Questionnaire in Patients on the Waiting List for a Kidney Transplant and Transplant Patients

Abstract

Background/Aims: The aim of this study is to explore the validity and reliability of the health-related quality of life SF-36 questionnaire in patients undergoing renal replacement therapy. Methods: A multicenter descriptive transversal study was carried out in Galicia, Spain, with patients undergoing renal replacement therapy. The tool used to measure the health-related quality of life was the authorized Spanish version of the ‘SF-36’ generic health questionnaire. The internal consistency of this survey was determined by means of interscale correlations and Cronbach’s α statistic. Validity was examined with a principal component exploratory factor analysis with Varimax rotation. Results: A total of 213 patients waiting for a kidney transplant and 72 recipients with a functioning renal transplant were studied. All the interscale correlations were positive and significant. The overall statistical value for Cronbach’s α was equal to 0.91 (95% CI: 0.91–0.94) and in all domains this value ranged from 0.7 to 0.92. The factor analysis identified 8 factors that explain 66.6% of the variance, 5 of which consisted of the same structure as 5 factors (domains) of the theoretical model. Conclusion: The SF-36 questionnaire is also a reliable and valid tool when used to measure the quality of life of patients undergoing renal replacement therapy.

Pretransplant Physical Functioning and Kidney Patients’ Risk for Posttransplantation Hospitalization/Death

“…(5). The mean physical functioning score that was reported in a study of patients in Spain was higher (74.2 Ϯ 24.0), but that mean was derived from scores of 72 patients with a functioning transplant as well as scores of 213 patients who were on the waiting list for a kidney transplant (8). Our study indicated that a higher level of physical functioning reported near the start of ESRD treatment was associated with reduced risk for a "bad event," i.e., hospital readmission, graft loss, and death, in the period after kidney transplantation.…”

Self-Rated Health Predicts Mortality and Graft Loss after Kidney Transplantation: A 10-Year Follow-Up Study

“…This scale was then categorized into tertiles: scores 0–30 (fair and poor) were categorized as ‘poor health’; 31–60 (good) as ‘average health’, and 61–100 (excellent and very good) as ‘excellent health’ [15]. The validity and reliability of the first item of the SF-36 has been confirmed in patients with renal disease, including those after KT [16,17,18]. …”

Physical methods for evaluating the nutrition status of hemodialysis patients

“…In addition, an indirect assessment of muscle mass can be performed via muscle strength, i.e. by using hand-grip test, or via subjective evaluation of the daily routine activities, as reported in specific questions of the SF-36 questionnaire [17].…”