Reliability and validity of the ESRD Symptom Checklist – Transplantation Module in Norwegian kidney transplant recipients

BACKGROUND The aim of the study was to validate the Norwegian version of a self-administered 43-item questionnaire designed to assess quality of life in kidney transplant recipients, the End-Stage Renal Disease Symptom Checklist--Transplantation Module (ESRD-SCL). METHODS In total, 53 kidney transplant recipients from one university-affiliated hospital responded to a questionnaire including the ESRD-SCL and the Short Form 36 (SF-36). We assessed internal consistency reliability and test-retest reliability with 2 weeks between assessments. Construct validity was assessed by correlations of the ESRD-SCL subscales with related and unrelated SF-36 scales, demographic, and clinical characteristics. RESULTS Subscales of the ESRD-SCL showed good internal consistency reliability (Cronbach's = 0.72-0.81) and for the aggregate total scale alpha was 0.94. Test-retest reliability median 14 days apart was excellent with intraclass coefficients ranging from 0.87 to 0.95. The pattern of correlations of the ESRD-SCL scales with related and unrelated scales SF-36 scales and demographic and clinical characteristics gave support to the construct validity of the ESRD-SCL. CONCLUSION The Norwegian translation of the ESRD-SCL showed satisfactory internal consistency reliability, test-retest reliability and construct validity, at the level of the original German version.