Effects of present pain level on recall of chronic pain and medication use.

The present study experimentally manipulated pain intensity in chronic pain patients to evaluate whether the present pain level influenced the recall of past pain and medication use. For 1 week 30 chronic pain patients recorded every change in their pain levels and every use of medication on an electronic diary. At the end of the week, we evaluated recall of pain level and medication use for the previous day and week either before (control group, n = 15) or immediately after a physical therapy (PT) session (PT group, n = 15). As expected, the PT patients reported a significantly lower present pain level than did the control patients. More importantly, the PT patients recalled their usual and their highest levels of pain for the previous day and week to be less severe than did the control patients; furthermore, they significantly underestimated these levels as compared to their diary. In contrast, the control patients significantly overestimated their lowest and highest levels of pain for the previous day and their usual and lowest levels of pain for the previous week. In addition, PT patients recalled taking significantly less medication than they had recorded in their diaries, and less than the control patients. Our results demonstrate clearly that chronic pain patients recall their pain and medication use for the previous day and week in a way that is congruent with their present pain intensity.