Understanding Bias in Clinical Trials: Performance and Detection

Reference: Cohen et al; SUSPECT study group. Can we avoid casting for suspected scaphoid fractures? A multicenter randomized controlled trial. J Orthop Traumatol. 2025 Date: May 1, 2025 Guest Skeptic: Dr. Matt Schmitz is an orthopedic surgeon specializing in Adolescent Sports Medicine and Young Adult Hip Preservation. He practices at the Rady Children’s Hospital in San Diego and is Professor of Orthopedics at UC San Diego. Case: A 48-year-old woman presents to the emergency department (ED) with left wrist pain after slipping on a wet pavement while walking into work. It was a FOOSH injury (fall on out-stretched hand). She did not lose consciousness and was able to drive herself to the ED, but she reports increasing wrist pain with movement. She rates the pain as 6/10 and notes it’s worse with lifting or rotating the wrist. She denies numbness, weakness, or swelling of the fingers. No previous wrist fractures or injuries. On inspection, she has no obvious deformity and minimal swelling at the wrist. The examination reveals tenderness in the anatomical snuffbox and over the scaphoid tubercle. Her range of motion is decreased due to pain, especially with radial deviation and wrist extension. Sensation and cap refill intact; radial pulse present. Plain radiographs (PA, lateral, scaphoid view) show no fracture. Background: Scaphoid fractures are a common injury seen in the ED but can represent a challenge to diagnose, even for experienced clinicians. The scaphoid injury is the most frequently fractured carpal bone, typically occurring after a fall onto an outstretched hand (FOOSH) in young, active individuals. The clinical dilemma arises when there is a high suspicion of fracture based on mechanism and physical exam (especially tenderness in the anatomical snuffbox), but the initial radiographs appear normal. An excellent SRMA on the history, physical exam, and imaging for scaphoid fractures was done by Carpenter et al AEM 2014. On SGEM#420, we wanted to know what to do with a patient who presents with a FOOSH injury and has a normal x-ray. Specifically, are there clinical exam findings that can help rule in/rule out a scaphoid fracture? The bottom line was there was no single physical examination maneuver that could reliably rule out an occult scaphoid fracture. Given this dilemma, ED physicians have erred on the side of caution. If a fracture is not radiographically visible, the patient is immobilized and referred for follow-up imaging in 10 to 14 days or orthopedic review. This conservative approach stems from the significant morbidity associated with missed scaphoid fractures, including non-union and avascular necrosis. However, this “cast first, confirm later” philosophy has led to over-treatment in most cases. Studies estimate that only 10–20% of patients with clinical suspicion of a scaphoid fracture and normal initial X-rays have a fracture confirmed on follow-up imaging. With this context, a new wave of research has emerged, questioning whether immediate casting is necessary or whether selective immobilization and early reassessment may be equally safe and more patient-centred. This ongoing debate challenges emergency physicians to balance the risks of under-treatment with the harms of unnecessary immobilization, time off work, and healthcare costs. Clinical Question: Can patients with suspected scaphoid fractures and normal initial radiographs be managed without casting, using a brief period of bandaging and reassessment? Reference: Cohen et al; SUSPECT study group. Can we avoid casting for suspected scaphoid fractures? A multicenter randomized controlled trial. J Orthop Traumatol. 2025 Population: Adults presenting to the ED with a clinical suspicion of scaphoid fracture but normal initial radiographs. Intervention: 3-day bandaging followed by reassessment. Comparison: Traditional 2-week casting with thumb spica. Outcome: