Persistent pain quality as a novel approach to assessing risk for disability in community-dwelling elders with chronic pain

Background: This study aims to test whether persistent pain quality is associated with incident or worsening disability in four domains: mobility, activity of daily living (ADL) and instrumental activity of daily living (IADL) difficulty, and physical performance. Methods: From the MOBILIZE Boston Study, a population-based cohort of adults aged ≥70 years, we studied participants with chronic pain who endorsed at least one pain quality descriptor (N = 398) and completed baseline and 18-month assessments. Pain quality was assessed using an adapted short-form McGill Pain Questionnaire with 20 pain quality descriptors in three categories: sensory, cognitive/affective, neuropathic. Persistence was defined as endorsing the same category at baseline and 18 months. Self-reported outcomes included mobility, ADL, and IADL difficulty. Physical performance was assessed using the short physical performance battery. Results: After adjusting for baseline pain severity and other covariates, individuals with three persistent categories had a greater risk of developing new or worsening IADL difficulty relative to those with one persistent category (relative risk [RR] 2.69, 95% confidence interval [CI] 1.34, 7.79). Similar results were observed for ADL difficulty (RR 5.83, 95% CI 1.32, 25.85), but no differences were noted in risk for mobility difficulty. There was no significant linear trend in physical performance over 18 months according to number of persistent categories (p =.68). Conclusion: Elders with persistent pain quality experienced a higher risk of developing new or worsening IADL and ADL disability with each additional category but not mobility difficulty or poorer physical performance. Longitudinal assessment of pain quality could be useful in determining risk for global disability among elders with chronic pain.