The Medication Quantification Scale 4.0: An Updated Index Based on Prescribers' Perceptions of the Risk Associated With Chronic Pain Medications.

To quantify risks associated with drug utilization in the real world for the treatment of chronic pain (CP), an index called the Medication Quantification Scale (MQS) was developed in 1992 in the United States and last updated in 2003. This study aimed to update, adapt to the contemporary Canadian context, and validate a revised version of the MQS (the MQS-4.0). Step 1: An expert committee adapted the MQS to the Canadian clinical practice context. Step 2: An update of risk weights given to medication subclasses was achieved using a prescriber survey (weights were derived from median 0-10 scores given to each subclass). Step 3: Construct validity of the MQS-4.0 was assessed after applying risk weights to the medication use profile of persons living with CP covered by public drug insurance plan. Thirty-six medication subclasses were included in the MQS-4.0. A total of 207 prescribers (physicians, pharmacists, and nurse practitioners) participated in the perception survey; 10.63% identified as pain specialists. When risk weights were applied to prescription claims (n = 9,122), the MQS-4.0 score was associated (P < .05) with the MQS-III score and variables associated with polypharmacy (eg, Charlson Comorbidity Index, number of prescribers or health care visits). This study provides an updated index intended for adult populations based on prescribers' perceptions of the risk associated with CP medications that can be useful for clinical practice and research among persons living with CP in Canada. It will, however, be relevant to verify whether similar risk weights are obtained in future pain specialist surveys. PERSPECTIVE: The MQS-4.0 is an update of the MQS used for quantifying the risk associated with the use of analgesics/coanalgesics. Adequate psychometrics properties were found.

Characteristics of complex regional pain syndrome in patients referred to a tertiary pain clinic by community physicians, assessed by the Budapest clinical diagnostic criteria.

OBJECTIVE: The aim of this study was to describe the characteristics of patients referred with complex regional pain syndrome (CRPS) diagnosis to a tertiary care pain center. METHOD: Descriptive chart review study of all patients referred by family physicians or community specialists as having CRPS (2006-2010). Data extraction included demographics, pain ratings, and diagnosis utilizing the Budapest CRPS criteria. RESULTS: The study population consisted of 54 subjects (male [M] =7, female [F] =47). Only 27.7% were classified as CRPS by the clinical expert. Four additional subjects carrying other diagnoses but found to have CRPS were added to the analysis. The non-CRPS group consisted of 39 subjects (M=8, F=31) and the CRPS group of 19 (M=2, F=17). CRPS patients were statistically significantly more likely to 1) have suffered a fracture; 2) report symptoms in each of the four symptom categories, as well as signs in three or four categories collectively; and 3) have allodynia/hyperalgesia alone or in combination (85/90%) as compared with the non-CRPS group (23/25%, respectively). The non-CRPS group was much more likely to report no symptoms or signs at all in the different symptom and sign categories. Of the 39 non-CRPS patients, 74% had other diagnosable entities (1/3 suffering from specific neuropathic pain conditions, e.g., radiculopathy, diabetic neuropathy, etc. and 2/3 from discreet musculoskeletal entities), while 18% were diagnosed with psychogenic pain disorders including conversion reaction associated with immobility or paralysis. DISCUSSION: Besides fulfilling the Budapest CRPS diagnostic criteria, the most important other factor for diagnosing CRPS is the exclusion of a neuropathic, musculoskeletal, or non-biomedical condition accounting for the presentation.