METHODS: Content validity was assessed by cross-sectional hybrid concept elicitation (CE) and cognitive interviews (CIs) performed across three rounds, to enable revision and subsequent testing of the SCCD. CE interviews investigated patients’ experiences, to examine whether the SCCD captured concepts of CC important to patients. CIs examined patients’ understanding of the SCCD item wording, recall period, and response options, as well as relevance of concepts, and ease of completion on an electronic clinical outcome assessment (eCOA) device. Interviews were audio recorded and transcribed verbatim. Transcripts were subject to thematic content analysis following each round of interviews, leading to SCCD revisions.

RESULTS: A total of 29 patients with CC from the USA (n=19) and UK (n=10) took part in an interview via telephone (n=24) or face-to-face (n=5). The mean age of patients was 49 (±12) years, 79% were female, and 80% had self-reported moderate or severe cough. CE interviews identified concepts important to patients’ experience related to CC. CIs confirmed that the SCCD-evaluated concepts important to patients and demonstrated that patients had a good understanding of item wording, response options, and the recall period. Patients who completed the electronic version of the SCCD (n=5) found the eCOA device easy to use.

CONCLUSIONS: The results of this study indicate the SCCD has sufficient content validity to evaluate patients’ experience of CC in clinical trials. Psychometric evaluation is now required to develop a scoring algorithm and examine measurement properties of the SCCD in the target population.