| This dissertation examines the transition from a new episode of back pain to persistent pain and disability in older adults. The aims are: 1) to describe the course of low back pain after a new healthcare visit, 2) to investigate predictors of persistent back pain and disability, and 3) to investigate the use and type of physical therapy interventions and their association with pain and disability compared to no physical therapy use. We used the Back pain Outcomes using Longitudinal Data (BOLD) registry, a prospective cohort study, for all analyses. BOLD consists of 5,239 adults ≥65 with a new visit for back pain. They are from primary care settings of three integrated healthcare systems in the United States. Data were collected at baseline and participants were followed for 12 months. Participants' electronic medical record data was also available during the 12 months before and after their index visit. The first study describes back related functional status [Roland Morris Disability Questionnaire (RMDQ)], a numerical rating scale of pain, pain interference with activity, and resolution of back pain at baseline, 3, 6 and 12 months. Small improvements in outcomes occurred over the 12 months, and only 22.6% of participants reported that their back pain had resolved at 12 months. Analysis for the second study investigated demographics, back pain characteristics, general health characteristics, comorbidities, and imaging findings as predictors of persistent back pain and disability. Gender; worse baseline clinical characteristics of back pain, leg pain, back-related disability, and duration of symptoms; smoking; anxiety; cervical pain; wide-spread pain syndromes; and an index diagnosis of lumbar spinal stenosis were predictive of both persistent back pain and persistent disability. Moderate or severe facet joint arthropathy was the only imaging finding associated with long-term function or pain. The last study used Marginal Structural Models to estimate the average causal effect for dosage of overall physical therapy, active physical therapy, passive physical therapy, and manual therapy use on pain and disability. Few patients used high levels of physical therapy. Higher use of active physical therapy was most consistently related to the greatest improvement in pain intensity. |
