RESUMEN
BACKGROUND: Qualitative patient interviews and patient-reported outcome instruments are important tools to understand the patient experience of disease. The aim of this study was to use patient interviews to identify concepts relevant and important to patients living with chronic kidney disease (CKD) stages 2-3b, develop a comprehensive conceptual model of the patient experience and debrief the Kidney Disease Quality of Life 36-item instrument (KDQOL-36) for patients with CKD stages 2-3b. METHODS: Concept elicitation interviews were conducted with patients with CKD stages 2-3b to identify signs/symptoms and impacts most relevant and important to patients (i.e., 'salient' concepts) and develop a conceptual model for the disease. Based on the salient concepts identified in the interviews, new items were proposed to supplement the KDQOL-36. Cognitive debriefing was performed to evaluate the KDQOL-36 and the additional items. RESULTS: A total of 31 patients were interviewed in this study (22 for concept elicitation and 15 for cognitive debriefing). The interviews identified 56 concepts (33 signs/symptoms and 23 impacts), 17 of which had not been identified in a previous literature review. Four signs/symptoms ('fatigue/lack of energy/tiredness', 'sleep problems', 'increased urination [including nocturia]' and 'swelling in legs/ankles/feet') and two impacts ('anxiety/worry' and 'general negative emotional/mental impact') were identified as salient. Of the salient signs/symptoms, three were not covered by the KDQOL-36 (sleep problems, increased urination and swelling in legs/ankles/feet) and were represented during cognitive debriefing interviews through four additional items (trouble falling asleep, trouble staying asleep, increased urination [including nocturia] and swelling in legs/ankles/feet) generated in the style of the KDQOL-36. All patients found the KDQOL-36 plus the four additional items relevant, and the majority found them clear. CONCLUSIONS: By identifying previously unknown concepts and augmenting the understanding of which are most important to patients, a comprehensive conceptual model was developed for patients who have CKD stages 2-3b. This study also demonstrates the suitability of the KDQOL-36 for patients who have CKD stages 2-3b and provides suggestions for how the instrument could be further developed to more comprehensively capture patient experience.