Gary H. Greenberg

The Canadian CT Head Rule for patients with minor head injury

BACKGROUND There is much controversy about the use of computed tomography (CT) for patients with minor head injury. We aimed to develop a highly sensitive clinical decision rule for use of CT in patients with minor head injuries. METHODS We carried out this prospective cohort study in the emergency departments of ten large Canadian hospitals and included consecutive adults who presented with a Glasgow Coma Scale (GCS) score of 13-15 after head injury. We did standardised clinical assessments before the CT scan. The main outcome measures were need for neurological intervention and clinically important brain injury on CT. FINDINGS The 3121 patients had the following characteristics: mean age 38.7 years); GCS scores of 13 (3.5%), 14 (16.7%), 15 (79.8%); 8% had clinically important brain injury; and 1% required neurological intervention. We derived a CT head rule which consists of five high-risk factors (failure to reach GCS of 15 within 2 h, suspected open skull fracture, any sign of basal skull fracture, vomiting >2 episodes, or age >65 years) and two additional medium-risk factors (amnesia before impact >30 min and dangerous mechanism of injury). The high-risk factors were 100% sensitive (95% CI 92-100%) for predicting need for neurological intervention, and would require only 32% of patients to undergo CT. The medium-risk factors were 98.4% sensitive (95% CI 96-99%) and 49.6% specific for predicting clinically important brain injury, and would require only 54% of patients to undergo CT. INTERPRETATION We have developed the Canadian CT Head Rule, a highly sensitive decision rule for use of CT. This rule has the potential to significantly standardise and improve the emergency management of patients with minor head injury.

A study to develop clinical decision rules for the use of radiography in acute ankle injuries

STUDY OBJECTIVE To develop decision rules that will predict fractures in patients with ankle injuries, thereby assisting clinicians in being more selective in their use of radiography. DESIGN Prospective survey of emergency department patients over a five-month period. SETTING Two university hospital EDs. PARTICIPANTS One hundred fifty-five adults in a pilot stage and 750 in the main study; all presented with acute blunt ankle injuries. INTERVENTIONS Thirty-two standardized clinical variables were assessed and recorded on data sheets by staff emergency physicians before radiography. MEASUREMENTS Variables were assessed for reliability by the kappa coefficient and for association with significant fracture on both ankle and foot radiographic series by univariate analysis. The data then were analyzed by logistic regression and recursive partitioning techniques to develop decision rules for predicting fractures in each radiographic series. MAIN RESULTS All 70 significant malleolar fractures found in the 689 ankle radiographic series performed were identified among people who had pain near the malleoli and were age 55 years or more, had localized bone tenderness of the posterior edge or tip of either malleolus, or were unable to bear weight both immediately after the injury and in the ED. This rule was 100% sensitive and 40.1% specific for detecting malleolar fractures and would allow a reduction of 36.0% of ankle radiographic series ordered. Similarly, all 32 significant midfoot fractures on the 230 foot radiographic series performed were found among patients with pain in the midfoot and bone tenderness at the base of the fifth metatarsal, the cuboid, or the navicular. CONCLUSION Highly sensitive decision rules have been developed and will now be validated; these may permit clinicians to confidently reduce the number of radiographs ordered in patients with ankle injuries.

Derivation of a Decision Rule for the Use of Radiography in Acute Knee Injuries

STUDY OBJECTIVE To derive a highly sensitive decision rule for the selective use of radiography in acute knee injuries. DESIGN Prospectively administered survey. SETTING Emergency departments of two university hospitals. PARTICIPANTS Convenience sample of 1,047 adults with acute knee injuries. RESULTS Attending emergency physicians assessed each patient for 23 standardized clinical findings, which were recorded on data collection forms. A total of 127 patients was examined independently by two physicians to determine interobserver agreement. The outcome measure was fracture of the knee. Any patients who did not have ED radiography underwent a structured telephone interview to determine the possibility of a missed fracture. Those variables found to be both reliable (highest kappa values) and strongly associated with a fracture (highest chi 2 values) were further analyzed by a recursive-partitioning multivariate technique. The derived decision rule included the following variables: (1) age 55 years or older, (2) tenderness at the head of the fibula, (3) isolated tenderness of the patella, (4) inability to flex to 90 degrees, and (5) inability to bear weight both immediately and in the ED (four steps). The presence of one or more of these findings would have identified the 68 fractures in the study population with a sensitivity of 1.0 (95% confidence interval [Cl], .95 to 1.0) and a specificity of .54 (95% Cl, .51 to .57). Application of the rule would have led to a 28.0% relative reduction in the use of radiography from 68.6% to 49.4% in the study population. CONCLUSION A practical, highly sensitive, and reliable decision rule for the use of radiography in acute knee injuries has been derived. Clinical application should await prospective validation of the rule.

Canadian C-Spine Rule study for alert and stable trauma patients: I. Background and rationale

This paper is Part I of a 2-part series to describe the background and methodology for the Canadian C-Spine Rule study to develop a clinical decision rule for rational imaging in alert and stable trauma patients. Current use of radiography is inefficient and variable, in part because there has been a lack of evidence-based guidelines to assist emergency physicians. Clinical decision rules are research-based decision-making tools that incorporate 3 or more variables from the history, physical examination or simple tests. The Canadian CT Head and C-Spine (CCC) Study is a large collaborative effort to develop clinical decision rules for the use of CT head in minor head injury and for the use of cervical spine radiography in alert and stable trauma victims. Part I details the background and rationale for the development of the Canadian C-Spine Rule. Part II will describe in detail the objectives and methods of the Canadian C-Spine Rule study.

Canadian C-Spine Rule study for alert and stable trauma patients: II. Study objectives and methodology

Clinical prediction rules are decision-making tools that incorporate three or more variables from the history, physical examination or simple tests. They help clinicians make diagnostic or therapeutic decisions by standardizing the collection and interpretation of clinical data. There is growing interest in the methodological standards for their development and validation. This article describes the methods used to derive the Canadian C-Spine Rule and provides a valuable reference for investigators planning to develop future clinical prediction rules.