Pain, Disablement Process and Frailty among Older Adults in the United States: Findings from the National Health and Aging Trends Study

Background: Musculoskeletal pain is highly prevalent among older adults and the most common cause of disability. Objectives: To examine 1) whether sociodemographic characteristics, comorbidities, depression, obesity and sleep complaints are independently associated with pain; 2) the effect of pain on upper-lower extremity functional limitation and disability; and 3) the effect of pain on frailty over 6-years pf follow-up among older adults. Design: Longitudinal study. Subjects: 5,716 participants aged 65 years and older from the National Health and Aging Trends Study (2011-2017) with complete information on pain and all the covariates of interest. Measures: Pain and pain location (shoulder, wrist, hand, hips, knees, ankle, neck, and back) are the independent variables. Socio-demographics (age, gender, marital status, race/ethnicity and years of formal education), sleep complaints, depression, body mass index, and comorbidities are covariates. The outcome measures were: pain, upper-lower extremity functional limitation, limitations in activities of daily living (ADL’s), and frailty. Analysis: Descriptive statistics were used to compare sample characteristics by pain and outcome variables. General estimation equations models were performed to examine predictors of pain and pain as predictor of upper-lower extremity functional limitations, ADL disability, and frailty over time. Results: Prevalence of pain in American older adults was 52.3% at baseline. The most prevalent pain location was knee (41.3%), followed by back (37.4%) and shoulder (32.3%). The odds of reporting pain were 0.99 (95% CI 0.97-1.01) over time. Pain was an independent predictor of upper extremity (UE) functional limitations (OR 1.90, 95% CI-1.66-2.16), lower extremity (LE) functional limitations (OR 1.52, 95% CI 1.42-1.63), ADL disability (OR 1.82, 95% CI 1.58-2.09), and frailty (OR 1.86, 95% CI 1.60-2.16) over time. Conclusions: Prevalence of pain among American older adults was high (52%). Pain is a strong independent predictor of functional limitations, ADL disability, and frailty. These findings suggest that early intervention and better management of pain is needed to prevent/delay disability and frailty, enhance patient management, allocation of health care resources, maintain independence and lower the burden of pain in this population.