Development of Focal Segmental Glomerulosclerosis Patient-Reported Outcome Measures: Symptom Diary and Symptom Impact Questionnaire

Abstract

Background: Focal segmental glomerulosclerosis (FSGS) is a kidney disease that affects patients' functioning and well-being. This study aimed to develop patient-reported outcome questionnaires to measure patient experiences related to FSGS.

Study design: Qualitative patient interviews to identify important symptoms and concepts (concept elicitation) formed the basis for the development of 2 questionnaires, one on symptoms and one on their impact. Additional qualitative interviews were implemented to evaluate/refine the questionnaires (cognitive debriefing). Transcripts of concept elicitation and cognitive debriefing interviews, conducted by telephone, were analyzed for concepts of interest using qualitative text analysis.

Setting & participants: Patients with FSGS (aged 18-65 years with estimated glomerular filtration rates ≥ 40mL/min/1.73m²) whose disease remained inadequately controlled after 2 or fewer courses of treatment.

Methodology: Qualitative concept elicitation and cognitive debriefing interviews.

Analytical approach: Interview transcripts were analyzed using qualitative software, MAXQDA.

Results: 30 patients completed concept elicitation interviews; 9 patients completed cognitive debriefing interviews. Frequently mentioned symptoms included swelling from the waist down/legs/knees/feet/ankles (67%), fatigue (57%), stomach/abdomen swelling (43%), body pain/pressure (30%), and shortness of breath (20%), as well as impacts on physical (52%), emotional (68%), and social functioning (89%). Based on analyses of interview transcripts and clinical input, 2 questionnaires, one on symptoms and one on the impact of the symptom, were drafted. The 23-item FSGS Symptom Diary (assessing the frequency and severity of FSGS symptoms during the past 24 hours) and the FSGS Symptom Impact Questionnaire (17 items assessing interference with activities and emotions during the past 7 days) were iteratively revised based on cognitive debriefing interviews.

Limitations: The study was restricted to English-speaking adults located in the United States, and the concept elicitation interview group had a low number of African Americans.

Conclusions: The FSGS Symptom Diary and FSGS Symptom Impact Questionnaire are new FSGS-specific patient-reported outcomes measures designed to support a comprehensive assessment of symptoms and symptom impact in adults with FSGS. Future research is needed to evaluate their quantitative measurement properties.

Keywords: FSGS Symptom Diary; FSGS Symptom Impact Questionnaire; Patient reported outcome (PRO); cognitive debriefing (CD); concept elicitation (CE); edema; focal segmental glomerulosclerosis (FSGS); idiopathic FSGS; kidney disease; qualitative research; semi-structured interview; side effect; swelling; symptom impact.