Guideline concordant care for acute low back pain: A mixed-methods analysis of determinants of implementation.

Introduction: We conducted an explanatory, sequential mixed-methods study to measure variation in the use of imaging and physical therapy (PT) for acute low back pain (LBP) and to identify implementation determinants that might explain variation in use across 22 EDs and 27 urgent cares in urban and rural locations within a community-based health system.

Methods: We described the patient population and measured concordance with LBP guideline recommendations on imaging and PT referral from January-June 2023. We conducted key informant interviews with physicians and advanced practice providers (APPs), n = 30, from these 49 sites between July - September 2023 and performed content analysis to identify implementation determinants to guideline concordance.

Results: From January-June 30, 2023, 1047 Intermountain Health employed or affiliated physicians and APPs at the 22 adult EDs and 27 adult UCs cared for 8047 patient encounters involving acute LBP with no red flags. 29% of acute LBP patient encounters included an imaging order (ED: 43%; UC: 18%) and 5% included a PT order (ED: 7%; UC: 4%). 17 ED and 13 UC physicians and APPs participated in semi-structured interviews. Their patient encounters represent 6% of the overall study population (ED: 5%; UC: 7%) with order rates and patient population characteristics similar to the full study population. ED and UC clinicians were generally familiar with LBP guideline recommendations but varied significantly in their knowledge and beliefs of the appropriate application of guidelines in evaluation and treatment plans.

Discussion: Guideline concordance for use of imaging and PT varied substantially across physicians and advance practice providers providing care at EDs and UC centers within a community-based health system. Implementation strategies that address barriers identified by this study, including varied understanding of the PT discipline, complex workflows for placing PT referrals, the medico-legal assurance that imaging provides, and the lack of feedback loops in ED and UC centers should be tested in future hybrid implementation-effectiveness trials to increase concordance to LBP guidelines and minimize harm related to overuse of imaging and underuse of conservative first-line treatment approaches.