Samenvatting

Background: There are many ways clinicians measure pain intensity in patients with musculoskeletal conditions, such as a Whiplash Associated Disorder.
Objective: To assess if some ratings of pain are scored systematically higher than others and whether this pattern changes with increasing symptom duration (acute and chronic WAD)
Methods: This study involves secondary analysis of data collected as part of three large studies (n= 361 at baseline) conducted in Sydney and Brisbane, Australia. Patient reported pain questions and scales were extracted from the existing data set. In each cohort, at each follow - up time point, mean scores for all the pain measures were converted to a 0-100 point by simple multiplication and plotted along with their 95% confidence intervals. Mean scores were compared by an analysis of variance (ANOVA).
Results: Mean pain scores from the acute cohort (Study 1) showed a clear pattern with the highest scores coming from the SF-36 Bodily Pain question, second the pain intensity item of the Neck Disability Index (NDI), and third the VAS scores (p< 0.05). Mean pain scores from the chronic patients in Study 2 showed large differences between some measures. The highest ratings again came from the SF-36 and the lowest from the NDI. Scores from the Functional Rating Index (FRI) and Numeric Rating Scale (NRS) felt between these two measurements but did not appear to be different from one another (p > 0.05)
Mean pain scores from the chronic patients in Study 3 showed a similar pattern in that SF-36 and NDI item scores were again the highest and lowest respectively. There was however a smaller, but not significant difference between the mean scores from all the measures in this cohort (14 weeks follow - up, p = 0.145, 6 months follow - up, p = 0.127)
Conclusion: Pain ratings from different measurement instruments reveal different outcomes.
The passage of time (after injury) does not appear to significantly influence the way pain is rated, the pattern of scores from the different measures is fairly consistent, no matter how long patients have had their symptoms.