A multicentre cross-sectional study to examine physicians’ ability to rule out a distal radius fracture based on clinical findings

We performed a multicentre cross-sectional observational study in the Emergency Departments of five Dutch hospitals from November 2010 to April 2014. The participating hospitals included one academic hospital, three teaching hospitals and one non-teaching hospital. The Medical Ethical Review Committees of all participating hospitals approved the study, without the need for informed consent.

Enrolment took place 24 h per day, 7 days a week. We included all consecutive adult patients (18 years and older) who presented to the Emergency Department in one of the participating hospitals with pain or tenderness secondary to wrist trauma. The wrist was defined as the proximal segment of the hand, including the carpal bones and the associated soft tissue, and the distal segment of the ulnar and radial bone. Wrist trauma was defined as any high or low energetic accident involving the wrist, such as a fall on outstretched hand (FOOSH). We excluded patients who had sustained multiple injuries (Injury Severity Score ≥ 16), whose injury had occurred 72 h prior and patients whose X-rays were requested prior to their visit to the Emergency Department (for example by their general practitioner). Additionally, physicians were instructed not to include patients if radiographs had already been ordered, for instance by their General Practitioner, and they were aware of the outcome (fracture present or not). This was ensured, by cross-checking the medical records of all patients 6 months after inclusion and verifying that radiographs had been requested by a provider from the same hospital (and not the General Practitioner). Additionally, the discharge letters were reviewed for any sign that patients had been referred to the Emergency Department with X-rays obtained elsewhere.

For all patients without radiographs taken on the initial visit, we assessed the radiology report during a 6 month period after the ED visit to check for missed fractures. Additionally, we contacted the patients by telephone and inquired if they had visited any other hospital since their ED visit or suffered from prolonged (>2 weeks) wrist pain.

Data was collected prospectively using standardized Case Record Forms (CRF). The assessors were asked to perform a standardized examination of each patient with pain or tenderness secondary to wrist trauma. Items included mechanism of injury, physical examination of the wrist and functional tests (Table 1). Additionally, they were asked to indicate the probability of the presence of a distal radius fracture on a 10-cm Visual Analogue Scale (VAS) from 0 to 100. Referral for radiography and type of treatment was at the discretion of the treating physician.

In the Netherlands, most Emergency Departments are run by emergency physicians. Providers include emergency physicians; emergency medicine registrars; surgical registrars; orthopaedic registrars; junior doctors not in training and 2nd year general practice registrars. Registrars are either supervised by emergency physicians or by their attending (surgeon or orthopaedic surgeon).

The assessors included interns under supervision of a registrar; junior doctors not in training; emergency medicine physicians; emergency medicine registrars; surgical registrars; orthopaedic registrars and 2nd year general practice registrars. All physicians (interns, emergency medicine physicians; emergency medicine registrars; surgical registrars; orthopaedic registrars and general practice registrars) received regular instructions and training on how to assess the clinical variables in a standardized manner. Additionally, we provided informative pocket cards and posters. Medical students and nurses operated under supervision and were instructed by one of the physicians.

The reference standard was the presence of a distal radius fracture on the conventional X-ray at presentation, as described in the radiologist report. A fracture was defined as the presence or disruption of one or more of the cortices of the bone. A fissure and an avulsion were recorded as a fracture. The reporting radiologist was blinded to the contents of the Case Record Forms. Patients without any bony fractures of the wrist were diagnosed with a wrist sprain or contusion. Radiographic series comprised at least one posterior-anterior (PA) and one lateral view with approximately 90 degrees of elbow flexion; and any further conventional imaging available (for example scaphoid series). Findings on additional Computed Tomography scans or Magnetic Resonance Image scans were not taken into account. Patients who were not imaged did not return or went elsewhere because persisting complaints were classified as not having sustained a distal radius fracture.

Data entry and analysis were performed with the Statistical Package for Social Sciences (SPSS) version 21.0 for Windows. We calculated test characteristics (sensitivity, specificity, predictive values and likelihood ratios) with 95 % confidence intervals for patients in the no risk group (0 % probability) and the definite fracture group (100 % probability).To estimate the ability of the assessors to discriminate between patients with and without a distal radius fracture, we calculated the area under the receiver operating characteristics curve (AUC) of the predicted probability. The AUC ranges from 0.5 to 1, with higher scores indicating better prediction.