Associations of Pain Characteristics with Long-term Trajectories of Physical Capacity among Older Adults in the United States

Bothersome and multisite pain are common and strongly associated with low physical functioning in older adults. Although these associations are well established in cross-sectional studies, few population-based studies have examined the impact of pain on physical functioning over time. Accordingly, we sought to determine the associations of pain characteristics with longitudinal trajectories of performance-based measures of physical capacity in older adults. Data on 6,783 community-dwelling adults aged ≥65 years who participated in the 2011-2017 National Health and Aging Trends Study were analyzed. Physical capacity was measured annually using the Short Physical Performance Battery. Group-based trajectory modeling was used to identify groups with similar longitudinal patterns of physical capacity. Baseline pain characteristics included report of bothersome pain in the past month, activity-limiting pain, location of pain, and pain medication use. Multinomial logistic regression was used to examine associations of pain characteristics with trajectories of physical capacity, adjusting for demographic and health characteristics. The cohort was 57% female, 68% white, and 58% were ≥75 years. Four distinct physical capacity trajectories were identified: “persistently low” (12% of cohort), “low, declining” (16%), “moderate, declining” (29%), and “persistently high” (43%). Participants who reported bothersome pain, activity-limiting pain, greater number of pain sites, and more frequent pain medication use at baseline were significantly more likely to demonstrate either “persistently low” or a declining physical capacity trajectory. For example, compared to those not reporting bothersome pain participants who reported bothersome pain were 79% (adjusted relative risk [RR]=1.79 [95%CI:1.26-2.55]), 75% (RR=1.75 [95%CI:1.42-2.16]), and 24% (RR=1.24 [95%CI:1.01-1.51]) more likely to have a “persistently low”, “low declining”, and “moderate declining” physical capacity trajectory, respectively. Among older adults in the US, bothersome pain and other pain characteristics were significantly associated with poor and worsening trajectories of physical capacity over a 6-year period. National Institute on Aging/NIH U01AG032947 and Scan Design Foundation.