Fig. 1

Health Care Utilization Adjusted Rates by First Provider Seen for Low Back Pain. PT = physical therapist; Chiro = chiropractor; Acu = acupuncturist; APRN = advanced practice registered nurse; PCP = primary care physician; PM&R = physical medicine and rehabilitation physician; Ortho = orthopedist; EM = emergency medicine physician “Other” category results available upon request. Margins refer to the marginal effect (dy/dx) at the means reported from the second stage (probit) of a two-stage residual inclusion instrumental variable approach. Models control for gender, age, co-morbidity, insurance status, rurality, county-level economic measures, and state limitations/provisions to physical therapy access; SE = standard error (robust)