Content Validation of the ATTR Amyloidosis Patient Symptom Survey: Findings from Patient and Clinician Cognitive Debriefing Interviews

PURPOSE: Amyloid transthyretin (ATTR) amyloidosis is a rare, progressive, and fatal disease. The ATTR Patient Symptom Survey (ATTR-PSS) was previously developed through literature review and concept elicitation input from clinicians and patients and revised after evaluation by a patient focus group. This study further evaluated the content validity of the ATTR-PSS through qualitative cognitive debriefing interviews with clinicians and patients. METHODS: Seven clinicians and 10 patients with ATTR amyloidosis were interviewed individually regarding their overall impressions, the clarity and appropriateness of the survey, relevance of concepts measured, and comprehensiveness and comprehensibility of items and response choice sets. RESULTS: Clinicians acknowledged the usefulness of the ATTR-PSS in research and clinical settings. They suggested minor modifications to the survey instructions, the addition of 3 symptoms, and the transfer of 10 conditions from the symptom list to 2 separate items. Patients found the ATTR-PSS to be easy to complete and relevant to their experiences. Their feedback resulted in modification to instruction text, edits to the description of 4 symptoms, removal of 1 symptom, and addition of 2 diagnoses. CONCLUSION: The findings support the content validity of the ATTR-PSS as an appropriate measure of symptom frequency, severity, and impact in patients with wild-type and hereditary ATTR amyloidosis.