Comparison of 2 methods of clinical data collection, one using the PAINOUT questionnaire (a European database for the management of postoperative pain)

Objetive: To compare postoperative pain intensity and incidence of adverse events when the evaluation is performed by a visual numerical scale completed by the patient (PAINOUT), or using a verbal numerical scale completed by ward nurses or the staff of the acute pain unit. Methods: Fifty-two postsurgical patients of both sexes (age range 31-80 years) admitted to the general surgery ward were sequentially recruited and evaluated on postoperative day 1. All patients were assessed using both questionnaires, which measure postoperative outcomes using scales of 0 to 10; values >= 4 were considered clinically relevant. The test and Cohen coefficient were used for statistical analysis. Results: Using the PAINOUT questionnaire, the mean maximum intensity of referred pain was 5.40 (range, 0-10) and the minimum intensity was 1.83 (range, 0-5). Mean values obtained with the verbal numerical scales used by staff on the ward and in the pain clinic were 3.76 (range, 0-10) and 0.97 (range, 0-5), respectively. The differences between the 2 methods of pain assessment were statistically (P = .006) and clinically significant. When evaluating nausea with PAINOUT questionnaire, all patients provided a response; in 88.5% the intensity was less than 4. Six patients reported nausea on the PAINOUT but not in the UDA questionnaire. Moreover, 61% of patients reported drowsiness/sedation in PAINOUT instrument, whereas none reported that effect on the verbal scale. Conclusions: The intensity of pain and adverse events is significantly higher when the patient evaluates and records its intensity on visual numerical scales compared with verbal numerical scales.