OBJECTIVES: Patient-reported outcomes (PROs) are increasingly used in clinical practices and pharmaceutical outcomes research, but the interpretation of the meaning of patient-level change in PROs remains problematic. This study assessed the reliability of assessing the Minimal Clinically Important Difference (MCID) from the patients’ perspective on pain and distress.

METHODS: A newly developed questionnaire was delivered to a general population sample through an online survey. Participants were asked to report their level of pain and distress (on a scale of 0 to 10), along with their estimated magnitude of meaningful improvement, worsening and level at which treatment is wanted or considered successful. Simple linear models and generalized tests of associations were used to analyze the variation in individual reporting of pain and distress.

RESULTS: The study received responses from 398 international participants (67% Europe, 18% U.S., 9% Canada). 93% of the respondents were White, 62% were aged 34 or younger, 59% were women, and 65% received a college education or higher. Depending on how patients were asked to report a personal MCID, 17% to 27% of participants reported paradoxical answers, defined as the direction of change opposing the intended question (i.e., reporting higher-than-initial pain under “improvement” question). Higher initial levels of pain or distress were significantly associated with higher level of changes viewed as an improvement (beta = 0.40 for pain, beta = 0.39 for distress, both p<.0001).

CONCLUSIONS: The respondents’ perceptions of change in pain and distress are not uniform and may even be contradictory. Those who suffer more from their health conditions may require a higher magnitude of change as sufficient improvement. More research is needed to understand the variation in PROs and what they would view as a MCID, while policymakers and clinical-standard setters should consider individual variation.