Use of a medication quantification scale for comparison of pain medication usage in patients with complex regional pain syndrome (CRPS)

Objective: To correlate the amount and types of pain medications prescribed to CRPS patients, using the Medication Quantification Scale, and patients' subjective pain levels. Design: An international, multisite, retrospective review. Setting: University medical centers in the United States, Israel, Germany, and the Netherlands. Subjects/Methods: A total of 89 subjects were enrolled from four different countries: 27 from the United States, 20 Germany, 18 Netherlands, and 24 Israel. The main outcome measures used were the Medication Quantification Scale III and numerical analog pain scale. Results: There was no statistically significant correlation noted between the medication quantification scale and the visual analog scale for any site except for a moderate positive correlation at German sites. The medication quantification scale mean differences between the United States and Germany, the Netherlands, and Israel were 9.793 (P<0.002), 10.389 (P<0.001), and 4.984 (P=0.303), respectively. Conclusions: There appears to be only a weak correlation between amount of pain medication prescribed and patients' reported subjective pain intensity within this limited patient population. The Medication Quantification Scale is a viable tool for the analysis of pharmaceutical treatment of CRPS patients and would be useful in further prospective studies of pain medication prescription practices in the CRPS population worldwide.