IntroductionLow back pain is a common problem and a substantial source of morbidity and disability worldwide. Patients frequently visit the emergency department (ED) for low back pain, but many experience persistent symptoms at 3 months despite frequent receipt of opioids. Although physical therapy interventions have been demonstrated to improve patient functioning in the outpatient setting, no randomised trial has yet to evaluate physical therapy in the ED setting.Methods and analysisThis is a single-centre cluster-randomised trial of an embedded ED physical therapy intervention for acute low back pain. We used a covariate-constrained approach to randomise individual physicians (clusters) at an urban academic ED in Chicago, Illinois, USA, to receive, or not receive, an embedded physical therapist on their primary treatment team to evaluate all patients with low back pain. We will then enrol individual ED patients with acute low back pain and allocate them to the embedded physical therapy or usual care study arms, depending on the randomisation assignment of their treating physician. We will follow patients to a primary endpoint of 3 months and compare a primary outcome of change in PROMIS-Pain Interference score and secondary outcomes of change in modified Oswestry Disability Index score and patient-reported opioid use. Our primary approach will be a modified intention-to-treat analysis, whereby all participants who complete at least one follow-up data time point will be included in analyses, regardless of their or their physicians’ adherence to their assigned study arm.Ethics and disseminationThis trial is funded by the US Agency for Healthcare Research and Quality (R01HS027426) and was approved by the Northwestern University Institutional Review Board. All physician and patient participants will give written informed consent to study participation. Trial results will be submitted for presentation at scientific meetings and for publication in peer-reviewed journals.Trial registration numberClinicalTrials.gov (NCT04921449)

Study Objectives: Three predictive scoring tools have been developed to identify low-risk patients with isolated subdural hematoma and preserved consciousness: the Orlando criteria, the SafeSDH Tool, and the Brain Injury Guidelines (BIG) criteria. We aim to validate and compare these three predictive tools in a single cohort of patients with isolated subdural hematomas.Methods: We performed a retrospective chart review of patients age > 16 with GCS >¼ 13 with CT-confirmed isolated subdural hematomas who presented to 1 academic and 3 community EDs. The Orlando criteria, SafeSDH Tool, and BIG criteria were applied to this dataset with a primary composite outcome (CO) of neurologic deterioration (severe headache, altered mental status, seizure, intubation), neurosurgical intervention, or death. Predictors used in the Orlando tool were: hematoma size and the presence of acute-on-chronic hematoma. The Orlando criteria was applied using the maximum sensitivity cutoff of 0.0235 from the derivation study. The Orlando Tool was also tested on both neurosurgical intervention (NI) (as in the derivation study), as well as the primary CO. The SafeSDH Tool includes the following predictors: use of warfarin, use of clopidogrel, number of hematomas, hematoma thickness, GCS, and midline shift. Cutoff used for this model was 0.0432, as in derivation. BIG criteria predictors included: intoxication, hematoma size, number of hematomas, and presence of skull fracture. Patients meeting both BIG1 and BIG2 criteria were considered low risk as these patients were deemed safe for management without neurosurgical consultation in derivation. The BIG criteria were not derived via regression, so no threshold cutoff was used and area under the receiver-operator curve (AUROC) was not calculated.