This research will use a novel approach to distinguish the short-term effects on LBP of physical activities from the long-term effects of such activities, by conducting a longitudinal case-crossover study nested within a cohort study. This design accounts for measured and unmeasured confounds by using each case as his/her own control- an entirely observational study that is analogous to a crossover experiment- capitalizing on modern mobile health and actigraphy technology. The primary exposures of interest are 10 self-reported physical activities commonly performed during work and activities of daily living, and actigraphy-assessed physical activity. Other exposures of interest include psychological factors, social factors, lifestyle-related factors, and work-related factors. The primary outcomes are participant-reported flares of low back pain (Aim 1) and participant-reported back-related functional limitations (mobility and activities of daily living [ADLs]) at 1-year follow-up, as measured by the Roland-Morris Disability Questionnaire. This observational study will include up to 550 Veterans with LBP aged 18 and older recruited from the VA Puget Sound Health Care System (VAPSHCS). The study will not affect participants' medical care in any way. After informed consent, recruitment, and baseline data collection, study participants will complete frequent, serial electronic e-Questionnaires using their own personal electronic devices (personal computer [PC], tablet, or smartphone) over the 1-year period of follow-up. Participants may also wear ActiGraph units for the 1st 4 weeks of follow-up. Long-term outcomes will be assessed by extended e-Questionnaires completed at 1-year follow-up. Aim 1 analyses will examine the short-term effects of 10 specific activity categories on participant-reported flares across all study assessments over 1-year follow-up. Aim 2 analyses will examine associations between the frequency of exposure to 10 specific activity categories over weeks 1-4 of follow-up, and long-term functional recovery at 12 months as defined by the RMDQ. All analyses will use a biopsychosocial framework accounting for potential confounders (sociodemographics, psychological factors, etc.) and effect modifiers, and will include sensitivity analyses to examine the robustness of findings and important study assumptions. This study was registered prior to the start of enrollment.
Low back pain (LBP) is the most common cause of disability worldwide. Although general activity is encouraged in the treatment of LBP, there is limited empirical information available on the specific types of activities that are beneficial or harmful for patients seen in primary care for LBP. This study will identify those physical activities with short-term (transient) effects on LBP exacerbations (or flares of LBP), as well as identifying the long-term (cumulative) effects of such activities on functional recovery.