Factor Structure of Pain Medication Questionnaire in Community-Dwelling Older Adults with Chronic Pain

Objectives: This study was to develop a version of the Pain Medication Questionnaire (PMQ) specific to the elderly chronic pain population and to identify relevant subscales and items for that population. Exploratory factor analysis (EFA) was conducted to assess the factor structure of the PMQ, to eliminate items that are not appropriate for this population, and to improve ease of administration in the elderly population. Methods: Data were obtained through a survey administered to older adults with chronic pain who consumed opioid medications in a cross-sectional study at outpatient clinics affiliated with the Baltimore Veterans Affairs Medical Center and the University of Maryland Medical System. EFA was conducted on the PMQ in the geriatric chronic pain population, which was compared with the PMQ studies from the general chronic pain population. Results: A two-factor solution yielded Factor 1 with four items and Factor 2 with three items; 18 items did not load significantly on either factor, and only seven items loaded significantly on either factor. All of the chosen factor loadings ranged from 0.41 to 0.88. Conclusion: The findings suggest that, although a small number of the items were identified from the overall scale, they adequately explain two relatively unique factors pertaining to pain management among older adults. This preliminary study suggests that the seven-item PMQ may be useful in assessing opioid medication misuse in community-dwelling older adults with chronic pain. Future studies are needed to confirm the reliability, validity, and factor structure of this modified PMQ in the geriatric population.