Importance of the type of provider seen to begin health care for a new episode low back pain: associations with future utilization and costs. 
Low back pain (LBP) care can involve many providers.  The provider chosen for entry into care may predict future health care utilization and costs.  The objective of this study was to explore associations between entry settings and future LBP-related utilization and costs.  A retrospective review of claims data identified new entries into health care for LBP.  We examined the year after entry to identify utilization outcomes (imaging, surgeon or emergency visits, injections, surgery) and total LBP-related costs.  Multivariate models with inverse probability weighting on propensity scores were used to evaluate relationships between utilization and cost outcomes with entry setting.  747 patients were identified (mean age = 38.2 (± 10.7) years, 61.2% female).  Entry setting was primary care (n = 409, 54.8%), chiropractic (n = 207, 27.7%), physiatry (n = 83, 11.1%) and physical therapy (n = 48, 6.4%).  Relative to primary care, entry in physiatry increased risk for radiographs (OR = 3.46, P = 0.001), advanced imaging (OR = 3.38, P < 0.001), injections (OR = 4.91, P < 0.001), surgery (OR = 4.76, P = 0.012) and LBP-related costs (standardized Β = 0.67, P < 0.001).  Entry in chiropractic was associated with decreased risk for advanced imaging (OR = 0.21, P = 0.001) or a surgeon visit (OR = 0.13, P = 0.005) and increased episode of care duration (standardized Β = 0.51, P < 0.001).  Entry in physical therapy decreased risk of radiographs (OR = 0.39, P = 0.017) and no patient entering in physical therapy had surgery.  Entry setting for LBP was associated with future health care utilization and costs.  Consideration of where patients chose to enter care may be a strategy to improve outcomes and reduce costs.