Cognitive interviewing in the evaluation of fatigue items: Results from the patient-reported outcomes measurement information system (PROMIS)

Cognitive Interviewing (CI) is a technique increasingly used to obtain respondent feedback on potential items during questionnaire development. No standard guidelines exist by which to incorporate CI feedback in deciding to retain, revise, or eliminate potential items. We used CI in developing fatigue items for the National Institutes of Health (NIH) Patient-Reported Outcomes Measurement Information System (PROMIS) Roadmap initiative. Our aims were to describe the CI process, formally evaluate the utility of decisions made on the basis of CI, and offer suggestions for future research. Participants were 22 patients with a diverse range of chronic health conditions. During CI, each participant provided feedback on a series of items. We then reviewed the CI data and decided whether to retain, revise, or eliminate each potential item. Following this, we developed or adopted three quantitative methods to compare retained versus eliminated items. Retained items raised fewer serious concerns, were less likely to be viewed as non-applicable, and were less likely to display problems with clarity or to make incorrect assumptions about respondents. CI was useful in developing the PROMIS fatigue items and the methods used to judge CI for the present item set may be useful for future investigations.