Recalled pain ratings: a complex and poorly defined task

Self-report ratings of pain intensity are ubiquitous in research and clinical practice. In addition to rating their current pain, patients are often asked to provide ratings to represent pain intensity over several days or weeks. Few data are available that provide insight into how people understand and accomplish this recall task. This study describes the results of structured interviews with 106 rheumatology patients with chronic pain about how they arrived at their ratings of pain intensity on a visual analog scale referenced to the past week. Most patients were unable to coherently articulate how they derived their ratings. Moreover, there was no consistency across patients. A variety of different strategies were identified that guided their responses. These results support the concern about the meaning and validity of retrospective recall ratings. Recall of pain, a seemingly simple task, is a deceptively more complex phenomenon. Efforts to improve the measurement of recalled pain need to be explored. Improving instructional sets, clearer specification of the dimensions of pain being targeted, avoiding use of a single item to measure pain, improved description of intended reference groups, and determining the length of time that patients are able to remember pain and limiting recall periods are reasonable methods that need to be explored.

These results emphasize our lack of a full understanding of the meaning of the information elicited by commonly used pain recall questions. They point to the potential importance of clearly specifying what qualities of pain are sought and how the patient should summarize them over the reporting period.