Memory for symptoms in COPD patients: how accurate are their reports?

The purpose of this study was to examine the accuracy of self-reports of symptom intensity in patients with chronic obstructive pulmonary disease (COPD) and factors that might influence recall of that intensity. Thirty COPD (forced expiratory volume in one second (FEV1) 36 +/- 17% predicted) subjects recorded their dyspnoea and fatigue intensity scores on a 0-10 scale for 14 consecutive days. On the fourteenth day, subjects recalled their average, greatest and least symptom intensity for the previous 14 days. General cognitive function, spirometry, and oxygenation were also measured. No significant differences were found between actual and recalled scores for dyspnoea or fatigue. General cognitive function, measured by the Mini Mental State Exam, correlated with the greatest and least dyspnoea and average fatigue difference scores (recall-actual) and contributed to the variance in the average and least dyspnoea recalled scores. The greatest contributor to the variance in the recall scores of both symptoms was the symptom intensity level on the day of recall. These results highlight the importance of current levels of symptom intensity and cognitive function when appraising symptoms in chronic obstructive pulmonary disease patients.