The quantitative analgesic questionnaire: A tool to capture patient-reported chronic pain medication use

Context The extent to which patients take chronic pain medications as prescribed is not well studied, and there are no generally agreed-upon measures. The Quantitative Analgesic Questionnaire (QAQ) is a new instrument designed to comprehensively document patient-reported medication use, generate scores to quantify it (by individual drug, class, and/or overall), and compare it (qualitatively and/or quantitatively) to the regimen as prescribed. Objectives The aim of this study was to describe the development and preliminary validation of the QAQ. Methods The QAQ was studied in a convenience sample of 149 HIV-infected participants. Results We found that the QAQ scores computed for participants' chronic pain medication regimens were valid based on their correlation with 1) patient-reported pain intensity (r = 0.38; P < 0.001) and 2) experienced pain management physicians' independent quantification of the regimens (r = 0.89; P < 0.001). The QAQ also demonstrated high interrater reliability (r = 0.957; P < 0.001). Detailed examination of the QAQ data in a subset of 34 participants demonstrated that the QAQ revealed suboptimal adherence in 44% of participants and contained information that would not have been gleaned from review of the medical record alone in 94%, including use of over-the-counter medications and quantification of "as needed" dosing. The QAQ also was found to be useful in quantifying change in the medication regimen over time, capturing a change in 50% of the participants from baseline to eight week follow-up. Conclusion The QAQ is a simple tool that can facilitate understanding of patient-reported chronic pain medication regimens, including calculation of percent adherence and generation of quantitative scores suitable for estimating and tracking change in medication use over time.