Pain Scores from a Questionnaire and Diary in Myogenous TMD

Objectives: to examine the correspondence between retrospective pain information from a questionnaire and actual pain information from a diary. Methods: pre-treatment data from 133 patients with myogenous Temporomandibular Disorders were obtained in a 2-week diary rating four times a day: pain intensity (100 mm VAS), and pain behavior (verbal scale). A pre-diary questionnaire rated: pain intensity (100 mm VAS, time or interval of pain not specified), (2) hampering of activity, (3) intra-day pain pattern, and (4) week-end pain. A post-diary questionnaire rated pain intensity. Results: the questionnaires’ VAS-scores (mean pre-diary 56.7 mm, post-diary 40.8 mm) were more similar to the maximal diary VAS-score than to the mean one (mean 56.6 mm and 29.1 mm respectively). Pearson’s correlation was the highest between the scores from the post-diary questionnaire and the maximal diary score (r=0.65). As a function of backward span of diary days, this correlation steeply increased when this span increased from 1 to 3 days, and the mean questionnaire’s score became similar to the maximal diary score for a span of 3 days. Little correspondence between questionnaire and diary occurred regarding hampering of activity by pain (low degree of correlation: r=0.14-0.19), intra-day pain pattern (questionnaire: hardly consistent pattern; diary: maximal pain on average late in the day for 79% of the patients) and predominant pain in the week-end (questionnaire: less than expected by chance; diary: pain uniformly distributed across the week). Conclusions: the findings on correlation and similarity between questionnaire and diary scores of pain intensity suggest that, when scoring the questionnaire, the patients use a memory for pain with a span of 3 days, thus emphasizing maximal and end pain. Because of the involvement of a memory for pain and the risk of ambiguous wording in a questionnaire, a diary is more reliable for detecting temporal pain patterns.