Interpretation of Renal Quality of Life Profile scores in routine clinical practice: an aid to treatment decision-making

Purpose: High Renal Quality of Life Profile (RQLP) scores are associated with impaired health-related quality of life; however, the clinical meaning of the scores is difficult for clinicians and healthcare planners to interpret. The aim of this study was to determine clinical significance of RQLP scores which could be used to aid clinical decision-making. Methods: The anchor-based technique (a method for categorizing numeric scores to ease interpretation) was used to develop a categorization system for the RQLP scores using a global question (GQ). The GQ scores (i.e. no effect to extremely large effect) were mapped against the RQLP scores, and intraclass correlation coefficient (ICC) was used to test their agreement. The RQLP and the GQ were administered to 260 adult patients (males = 165 and females = 95) with chronic renal failure (CRF). Results: The mean RQLP score was 67.2, median = 61, SD = 41.5, and range 0-172. The mean GQ score was 1.74, median = 2, SD = 1.27, and range 0-4. The mean, mode, and median of the GQ scores for each RQLP score were used to devise several sets of categories of RQLP score, and the ICC test of agreement was calculated. The proposed set of RQLP score banding for adoption includes: 0-20 = no effect on patient's life (GQ = 0, n = 35); 21-51 = small effect on patient's life (GQ = 1, n = 66); 52-93 = moderate effect on patient's life (GQ = 2, n = 87); 94-134 = very large effect on patient's life (GQ = 3, n = 54); and 135-172 = extremely large effect on patient's life (GQ = 4, n = 18). The ICC coefficient for the proposed banding system was 0.80. Conclusion: The proposed categorization of the RQLP will aid the clinical interpretation of change in RQLP score informing treatment decision-making in routine practice.