Physical Therapy as the First Point of Care to Treat Low Back Pain: An Instrumental Variables Approach to Estimate Impact on Opioid Prescription, Health Care Utilization, and Costs.

OBJECTIVE: To compare differences in opioid prescription, health care utilization, and costs among patients with low back pain (LBP) who saw a physical therapist (PT) at the first point of care, at any time during the episode or not at all. DATA SOURCES: Commercial health insurance claims data, 2009-2013. STUDY DESIGN: Retrospective analyses using two-stage residual inclusion instrumental variable models to estimate rates for opioid prescriptions, imaging services, emergency department visits, hospitalization, and health care costs. DATA EXTRACTION: Patients aged 18-64 years with a new primary diagnosis of LBP, living in the northwest United States, were observed over a 1-year period. PRINCIPAL FINDINGS: Compared to patients who saw a PT later or never, patients who saw a PT first had lower probability of having an opioid prescription (89.4 percent), any advanced imaging services (27.9 percent), and an Emergency Department visit (14.7 percent), yet 19.3 percent higher probability of hospitalization (all p \u3c .001). These patients also had significantly lower out-of-pocket costs, and costs appeared to shift away from outpatient and pharmacy toward provider settings. CONCLUSIONS: When LBP patients saw a PT first, there was lower utilization of high-cost medical services as well as lower opioid use, and cost shifts reflecting the change in utilization