Additional Validation of the Pain Medication Questionnaire in a Sample of Patients with Chronic Pain
The present study represents an initial stage in the formal attempt to aid in developing a psychometrically sound, self-report screen tool used for assessing potential pain medication misuse risk. This study follows previous studies of Adams and colleagues (2004) and Holmes and colleagues (2006). The Pain Medication Questionnaire (PMQ), initially a 26-item instrument, was studied as a 23-item questionnaire designed to measure risk for opioid misuse. This revised PMQ showed good reliability and validity. This study also examined the ability of the revised PMQ to predict pain medication misuse in a heterogeneous sample of chronic pain patients. The PMQ was administered to 1,540 patients at a pain center that provided interdisciplinary pain management, including medication, psychological, and physical therapy disciplines. The risk of a patient's pain medication misuse, as predicted by the PMQ, was found to significantly decrease following interdisciplinary intervention. Cut-off scores were created from the distributed PMQ scores by assessing a frequency scatter plot and determined that those participants with scores below a 21 on the PMQ made up the lowest (L-PMQ) group, scores including and between 21 to 30 on the PMQ made up the middle (M-PMQ) group, and scores above 30 made up the highest (H-PMQ) group. A comparison using the H-PMQ and L-PMQ groups revealed that those participants in the H-PMQ group, after completing an interdisciplinary treatment program, had significantly decreased PMQ scores at post-treatment. In addition, the H-PMQ group was significantly associated with greater levels of non-compliance or drop out from treatment, early pain medication refill requests, and endorsement of having a history of alcohol abuse or history of rehab for alcohol or drugs. Finally, the present study also examined the relationship of total PMQ score with measures of physical impairment and perceived pain. Findings suggest that higher scores on the PMQ are minimally associated with higher levels of impairment of physical functioning and perceived pain.