Simplified Clinical Decision Rule Using Clinically Important Events for Risk Prediction in Pediatric Head Injury: A Retrospective Cohort Study

Computed tomography (CT) scans are useful for confirming head injury diagnoses. However, there is no standard clinical decision rule (CDR) for determining the need for CT scanning in pediatric patients with head injuries. We developed a CDR and conducted a retrospective cohort study to evaluate its diagnostic accuracy in identifying children with clinically important traumatic brain injury (ciTBI). We selected predictors based on three existing CDRs: CATCH, CHALICE, and PECARN. Of the 2569 eligible patients, 645 (439 (68%) boys, median age: five years) were included in this study. In total, 59 (9%) patients showed ciTBI, and 129 (20%) were admitted to hospital. The novel CDR comprised six predictors of abnormal CT findings. It had a sensitivity of 79.5% (95% confidence interval (CI): 65.5–89.0%) and a specificity of 50.9% (95% CI: 48.9–52.3%). The area under the receiver-operating characteristic curve (0.72, 95% CI: 0.67–0.77) was non-inferior to those of CATCH, CHALICE, and PECARN (0.71, 95% CI: 0.66–0.77; 0.67, 95% CI: 0.61–0.74; and 0.69, 95% CI: 0.64–0.73, respectively; p = 0.57). The novel CDR was statistically noninferior in diagnostic accuracy compared to the three existing CDRs. Further development and validation studies are needed before clinical application.

The Hip Center Rule Can be Used to Decide if Measured Pelvic Incidence is Accurate

Study Design Simulation study. Objective Pelvic incidence (PI) should be considered during surgical planning. The ideal patient position with both hip centers perfectly aligned for a lateral radiograph is rarely obtained. It has been suggested that a radiograph with axial and coronal rotation up to 20° is acceptable to obtain a measured PI within 6 degrees of the actual PI. We seek to: (1) evaluate the effect of variations in PI and patient malpositioning on measured vs true PI, and (2) determine whether the presence of one hip center within the bony acetabular rim of the contralateral hip can serve as a simple clinical decision rule on the accuracy of measured PI. Methods Published anthropometric three-dimensional pelvic landmark coordinates were used in this study. Radiographic projections were generated using linear algebra for combinations of axial and coronal rotation from −20° to +20°. True and measured PIs were compared. Results Rotation to 20° cannot be uniformly accepted as decision rule. Pelvises with higher PIs are more sensitive to malpositioning with greater PI deviation with smaller amounts of rotation. Diagnostic performance of the hip center rule demonstrated a sensitivity of 25.58% and a specificity of 100.00%. Conclusions Rather than assessing the quality of radiographs for PI measurement by magnitude of malpositioning, we recommend clinicians use the “hip center rule.” As long as at least one hip center is contained within the bony acetabular rim of the contralateral hip, there is high confidence that measured PI will be within 6° of true PI.

External validation of a clinical decision rule and neuroimaging rule-out strategy for exclusion of subarachnoid haemorrhage in the emergency department: A prospective observational cohort study

Background The investigation of suspected subarachnoid haemorrhage (SAH) presents a diagnostic dilemma. The limited sensitivity of a negative CT brain scan has historically mandated hospital admission and a lumbar puncture to look for evidence of blood in the cerebrospinal fluid. However, emerging evidence has suggested the sensitivity of clinical decision rules and modern CT imaging protocols within early onset of symptoms, may be sufficient to exclude the diagnosis. Methods A prospective, multi-centre, observational study of consecutive adult patients with acute severe non-traumatic headache presenting to emergency departments. We plan to recruit 9000 patients from over a hundred sites across the UK. The primary outcome is adjudicated SAH as defined by neuroimaging or cerebrospinal fluid findings consistent with the diagnosis. Data will be collected on clinical history, examination findings, phlebotomy and imaging results. All participants will be followed for 28-days to identify SAH and other clinically relevant outcomes using case note review, and later Hospital Episode Statistics. A proportionate opt-out model of consent will be used to maximise patient recruitment and study generalisability. Discussion Whilst there is increasing evidence that early neuroimaging strategies for the diagnosis of SAH are very sensitive, there have been no large studies to confirm this in the UK population. Furthermore, the test characteristics of CT brain beyond 6 hours from onset are not well understood and there is limited biological plausibility for this defined time cutpoint. Finally, the performance of the Ottawa clinical decision rule has shown promise in the Canadian population. However, its performance in the UK has not been studied and there are concerns that due to the low specificity it may result in increased, rather than decreased rate of investigations. This study will therefore aim to assess the test characteristics of both a CT brain up to 24h from presentation and the Ottawa SAH clinical decision rule.