(182) What do Patients with Acute and Chronic Pain Think about Rating the Intensity of their Pain? Insights from ACTTION's QUALITE-Pain Concept Elicitation Interviews

Patient-reported measures of pain intensity (i.e., numerical rating scales, visual analogue scales, and verbal rating scales) have been found to be reliable and valid in clinical trials. However, interpretations of pain intensity measures may vary within- and between-patients, potentially reducing pain intensity rating reliability. As part of ACTTION's efforts to develop an FDA-qualified measure of pain intensity (i.e., QUALIfied for the Therapeutic Evaluations of Pain; QUALITE-Pain), we conducted a multi-site qualitative study to interview individuals with acute (n=22) and chronic pain conditions (n=22) about their interpretations of existing pain intensity measures. When defining ‘pain intensity’, respondents primarily described the quantity of pain (77% for both acute and chronic), but also included other concepts (e.g., pain interference, tolerability, duration). When rating pain intensity, respondents considered their inability to participate in daily activities (64% of acute respondents; 59% chronic), the effects of lack of sleep and stress on pain (63% acute; 45% chronic), and emotions about pain (40% acute; 54% chronic). Regarding time period to be rated, all respondents with acute pain defined ‘now’ as pain intensity in the current moment. For respondents with chronic pain, ‘today’ was primarily defined as pain from waking until the present moment (68%), although other definitions included current pain or pain during the middle of the day. Respondents with chronic pain defined ‘over the past 24 hours’ as the pain experienced over the past 24 hours (59%), whereas other descriptions focused on pain today, since waking, or during the first half of the day. Pain intensity measures are generally included in primary efficacy outcomes in pain treatment clinical trials, and therefore idiosyncrasies and variability in interpretations of these measures may decrease assay sensitivity. Respondent perspectives in this study point to ways in which pain intensity measures may be improved (e.g., clarifying instructions and measure wording).