Assessing persistent cancer pain: a comparison of current pain ratings and pain recalled from the past week

Recent guidelines developed by the U.S. Food and Drug Administration for the use of patient-reported outcomes discuss the rating of pain and other symptoms at their current level of severity versus rating these symptoms using a recall period, such as the past 24 hours or past week. To explore whether the overall experience of cancer patients is better represented by ratings of current pain or pain recalled from the past week, we conducted a secondary analysis of Eastern Cooperative Oncology Group data from 1147 patients with cancer who had reported having persistent pain during the past week. Patients used the Brief Pain Inventory (BPI) to rate their current pain along with their pain at its worst, least, and average during the past week. T-tests were used to compare ratings of current pain and pain recalled from the past week. Linear regressions described the extent to which the various pain ratings contributed to overall pain interference, also derived from the BPI. Overall, patients rated their current pain as less severe than their worst or average pain recalled from the past week. Worst pain recalled from the past week contributed most to ratings of pain interference. These findings indicate that ratings of recalled worst pain, rather than ratings of current pain, might better reflect the overall experience of pain and its impact on function in cancer patients with persistent pain. Our results provide information that might guide the choice of recall period for cancer clinical trials with pain as a self-reported outcome.