Andrew Worster

Screening for Intimate Partner Violence in Health Care Settings: A Randomized Trial

CONTEXT Whether intimate partner violence (IPV) screening reduces violence or improves health outcomes for women is unknown. OBJECTIVE To determine the effectiveness of IPV screening and communication of positive results to clinicians. DESIGN, SETTING, AND PARTICIPANTS Randomized controlled trial conducted in 11 emergency departments, 12 family practices, and 3 obstetrics/gynecology clinics in Ontario, Canada, among 6743 English-speaking female patients aged 18 to 64 years who presented between July 2005 and December 2006, could be seen individually, and were well enough to participate. INTERVENTION Women in the screened group (n=3271) self-completed the Woman Abuse Screening Tool (WAST); if a woman screened positive, this information was given to her clinician before the health care visit. Subsequent discussions and/or referrals were at the discretion of the treating clinician. The nonscreened group (n=3472) self-completed the WAST and other measures after their visit. MAIN OUTCOME MEASURES Women disclosing past-year IPV were interviewed at baseline and every 6 months until 18 months regarding IPV reexposure and quality of life (primary outcomes), as well as several health outcomes and potential harms of screening. RESULTS Participant loss to follow-up was high: 43% (148/347) of screened women and 41% (148/360) of nonscreened women. At 18 months (n = 411), observed recurrence of IPV among screened vs nonscreened women was 46% vs 53% (modeled odds ratio, 0.82; 95% confidence interval, 0.32-2.12). Screened vs nonscreened women exhibited about a 0.2-SD greater improvement in quality-of-life scores (modeled score difference at 18 months, 3.74; 95% confidence interval, 0.47-7.00). When multiple imputation was used to account for sample loss, differences between groups were reduced and quality-of-life differences were no longer significant. Screened women reported no harms of screening. CONCLUSIONS Although sample attrition urges cautious interpretation, the results of this trial do not provide sufficient evidence to support IPV screening in health care settings. Evaluation of services for women after identification of IPV remains a priority. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00182468.

Problems with use of composite end points in cardiovascular trials: systematic review of randomised controlled trials

Objective To explore the extent to which components of composite end points in randomised controlled trials vary in importance to patients, the frequency of events in the more and less important components, and the extent of variability in the relative risk reductions across components. Design Systematic review of randomised controlled trials. Data sources Cardiovascular randomised controlled trials published in the Lancet, Annals of Internal Medicine, Circulation, European Heart Journal, JAMA, and New England Journal of Medicine, from 1 January 2002 to 30 June 2003. Component end points of composite end points were categorised according to importance to patients as fatal, critical, major, moderate, or minor. Results Of 114 identified randomised controlled trials that included a composite end point of importance to patients, 68% (n=77) reported complete component data for the primary composite end point; almost all (98%; n=112) primary composite end points included a fatal end point. Of 84 composite end points for which component data were available, 54% (n=45) showed large or moderate gradients in both importance to patients and magnitude of effect across components. When analysed by categories of importance to patients, the most important components were associated with lower event rates in the control group (medians of 3.3-3.7% for fatal, critical, and major outcomes; 12.3% for moderate outcomes; and 8.0% for minor outcomes). Components of greater importance to patients were associated with smaller treatment effects than less important ones (relative risk reduction of 8% for death and 33% for components of minor importance to patients). Conclusion The use of composite end points in cardiovascular trials is frequently complicated by large gradients in importance to patients and in magnitude of the effect of treatment across component end points. Higher event rates and larger treatment effects associated with less important components may result in misleading impressions of the impact of treatment.

Understanding receiver operating characteristic (ROC) curves.

1conclude that serum levels of neuron-specific enolase (NSE), a biochemical marker of ischemic brain injury, may have clinical utility for the prediction of survival to hospital discharge in patients experiencing the return of spontaneous circulation following at least 5 minutes of cardiopulmonary resuscitation. The authors used a receiver operating characteristic (ROC) curve to illustrate and evaluate the diagnostic (prognostic) performance of NSE. We explain ROC curve analysis in the following paragraphs. The term “receiver operating characteristic” came from tests of the ability of World War II radar operators to determine whether a blip on the radar screen represented an object (signal) or noise. The science of “signal detection theory” was later applied to diagnostic medicine. 2

Prospective validation of the ABCD2 score for patients in the emergency department with transient ischemic attack

Background: The ABCD2 score (Age, Blood pressure, Clinical features, Duration of symptoms and Diabetes) is used to identify patients having a transient ischemic attack who are at high risk for imminent stroke. However, despite its widespread implementation, the ABCD2 score has not yet been prospectively validated. We assessed the accuracy of the ABCD2 score for predicting stroke at 7 (primary outcome) and 90 days. Methods: This prospective cohort study enrolled adults from eight Canadian emergency departments who had received a diagnosis of transient ischemic attack. Physicians completed data forms with the ABCD2 score before disposition. The outcome criterion, stroke, was established by a treating neurologist or by an Adjudication Committee. We calculated the sensitivity and specificity for predicting stroke 7 and 90 days after visiting the emergency department using the original “high-risk” cutpoint of an ABCD2 score of more than 5, and the American Heart Association recommendation of a score of more than 2. Results: We enrolled 2056 patients (mean age 68.0 yr, 1046 (50.9%) women) who had a rate of stroke of 1.8% at 7 days and 3.2% at 90 days. An ABCD2 score of more than 5 had a sensitivity of 31.6% (95% confidence interval [CI] 19.1–47.5) for stroke at 7 days and 29.2% (95% CI 19.6–41.2) for stroke at 90 days. An ABCD2 score of more than 2 resulted in sensitivity of 94.7% (95% CI 82.7–98.5) for stroke at 7 days with a specificity of 12.5% (95% CI 11.2–14.1). The accuracy of the ABCD2 score as calculated by either the enrolling physician (area under the curve 0.56; 95% CI 0.47–0.65) or the coordinating centre (area under the curve 0.65; 95% CI 0.57–0.73) was poor. Interpretation: This multicentre prospective study involving patients in emergency departments with transient ischemic attack found the ABCD2 score to be inaccurate, at any cut-point, as a predictor of imminent stroke. Furthermore, the ABCD2 score of more than 2 that is recommended by the American Heart Association is nonspecific.

Assessment of inter-observer reliability of two five-level triage and acuity scales: a randomized controlled trial

INTRODUCTION The Emergency Severity Index (ESI) is an initial measure of patient assessment in the emergency department (ED). It rates patients based on acuity and predicted resource intensity from Level 1 (most ill) to Level 5 (least resource intensive). Already implemented and evaluated in several US hospitals, ESI has yet to be evaluated in a Canadian setting or compared with the five-level Canadian Emergency Department Triage and Acuity Scale (CTAS). OBJECTIVE To compare the inter-observer reliability of 2 five-level triage and acuity scales. METHODS Ten triage nurses, who had all been trained in the use of CTAS, from 4 urban, academic Canadian EDs were randomly assigned either to training in ESI version 3 (ESI v.3) or to refresher training in CTAS. They independently assigned triage scores to 200 emergency cases, unaware of the rating by the other nurses. RESULTS Number of years of nursing practice was the only significant demographic difference found between the 2 groups (p = 0.014). A quadratically weighted kappa to measure the inter-observer reliability of the CTAS group was 0.91 (0.90, 0.99) and not significantly different from that of the ESI group 0.89 (0.88, 0.99). An inter-test generalizability (G) study performed on the variance components derived from an analysis of variance (ANOVA) revealed G(5) = 0.90 (0.82, 0.99). CONCLUSIONS After 3 hours of training, experienced triage nurses were able to perform triage assessments using ESI v.3 with the same inter-observer reliability as those with experience and refresher training in using the CTAS.

Capability of ischemia-modified albumin to predict serious cardiac outcomes in the short term among patients with potential acute coronary syndrome

Background: Ischemia-modified albumin (IMA) has been suggested as a marker of cardiac ischemia. Little, however, is known about its capacity to predict short-term serious cardiac outcomes (death, myocardial infarction, congestive heart failure, serious arrhythmia, or refractory ischemic cardiac pain) in patients arriving at the emergency department with symptoms that may indicate cardiac ischemia. Methods: We screened 546 patients over a 4-week period, of whom 189 fulfilled our entry criteria by presenting to an emergency department with potential cardiac-ischemia symptoms within 6 hours after chest pain, seeing an emergency physician who chose to order a troponin I test, and having no serious cardiac outcome before the troponin result became available. We followed the study patients for 72 hours to determine if any experienced a serious cardiac outcome. We calculated the likelihood ratios (LRs) of IMA findings predicting serious cardiac outcomes that could not be diagnosed at presentation with current techniques. Results: Of the 189 patients, 24 had a serious cardiac outcome within 72 hours after their arrival at the emergency department. The likelihood ratios for IMA measurement within 6 hours after chest pain predicting a serious cardiac outcome within the next 72 hours were 1.35 (95% confidence interval [CI] 0.315–5.79) for IMA ≤ 80 U/mL and 0.98 (95% CI 0.86– 1.11) for IMA > 80 U/mL. Conclusions: These data suggest that in patients presenting with chest pain who have not yet experienced a serious cardiac event, IMA is a poor predictor of serious cardiac outcomes in the short term.

How does fast track affect quality of care in the emergency department

Study objectives Use of fast track has been shown to improve the emergency department flow of less urgent patients. It has been speculated, however, that this could negatively affect the care of urgent patients. The objective of this study was to determine whether a dedicated fast track for less urgent patients [Canadian Triage and Acuity scale category 4/5 (CTAS 4/5)] affected (1) the time to assessment for urgent patients (CTAS 3), (2) the length of stay for less urgent patients (CTAS 4 and 5), and (3) the left-without-being-seen rate. Methods In June 2003, fast track was opened in our emergency department from 13:00 to 19:00 h. A before–after intervention comparison analysis was completed for 1 week in Aug 2002 and the same week in Aug 2003. Data collected included (1) time to assessment of CTAS 3 patients, (2) the length of stay for CTAS 4/5 patients, and (3) percentage of patients who left without being seen. Results A total of 368 patients were reviewed for 2002 and 380 patients were reviewed for 2003. Median time to assessment of CTAS 3 patients presenting from 13:00 to 19:00 h was reduced from 66 min (Interquartile range: 40, 94 min) in 2002 to 60 min (IQR: 38, 108 min) after fast track was open in 2003 (P=0.95). Median length of stay of CTAS 4 and 5 patients was reduced from 170 min (IQR: 111, 256 min) to 110 min (IQR: 69, 185 min) (P<0.001). The overall left-without-being-seen rate decreased from 5% (20/368) to 2% (9/380). Conclusion A dedicated fast track for CTAS 4/5 patients can reduce the length of stay and the left-without-being-seen rate with no impact on CTAS 3 patients seen in the main emergency department.

Incorporation bias in studies of diagnostic tests: how to avoid being biased about bias.

Adiagnostic test’s ability to discriminate between those with and without a condition of interest (e.g., a specific disease) is best determined by comparing the test result to a reference standard that is accepted as the “truth.” The evaluation of a diagnostic test’s performance involves comparing its results to this reference standard, and commonly reported test characteristics such as sensitivity and specificity can be determined during this kind of assessment (Fig. 1). The reference standard can take several forms. These include other diagnostic tests such as magnetic resonance imaging, a histopathology report or findings on autopsy. A reference standard may be a clinical outcome such as death or the resolution of symptoms. The reference standard may also be the results of a clinical evaluation or expert opinion. At times, the most challenging aspect of assessing a diagnostic test is identifying a reference standard that will be widely accepted. Sometimes no acceptable reference standard exists. There is some recent work into dealing with this dilemma. Ideally, the reference standard and the diagnostic test under consideration are entirely independent of one another. When both the diagnostic test and the reference standard are laboratory tests, this is rarely a problem. Similarly, when the reference standard includes death, the independence of the diagnostic test and reference standard is seldom in question. However, when some clinical judgment or interpretation is required and the physician uses the diagnostic test in his or her decision-making, independence is lost. In this issue of CJEM, Mater and colleagues evaluated the diagnostic test characteristics of plain radiographs in the form of a shunt series and CT scanning of the head to determine whether children have cerebrospinal shunt malfunction. These authors chose a clinical assessment as the reference standard, and specifically defined shunt

Withholding versus Continuing Angiotensin-converting Enzyme Inhibitors or Angiotensin II Receptor Blockers before Noncardiac Surgery: An Analysis of the Vascular events In noncardiac Surgery patIents cOhort evaluatioN Prospective Cohort.

Background: The effect on cardiovascular outcomes of withholding angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers in chronic users before noncardiac surgery is unknown. Methods: In this international prospective cohort study, the authors analyzed data from 14,687 patients (including 4,802 angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker users) at least 45 yr old who had in-patient noncardiac surgery from 2007 to 2011. Using multivariable regression models, the authors studied the relationship between withholding angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers and a primary composite outcome of all-cause death, stroke, or myocardial injury after noncardiac surgery at 30 days, with intraoperative and postoperative clinically important hypotension as secondary outcomes. Results: Compared to patients who continued their angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers, the 1,245 (26%) angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker users who withheld their angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers in the 24 h before surgery were less likely to suffer the primary composite outcome of all-cause death, stroke, or myocardial injury (150/1,245 [12.0%] vs. 459/3,557 [12.9%]; adjusted relative risk, 0.82; 95% CI, 0.70 to 0.96; P = 0.01) and intraoperative hypotension (adjusted relative risk, 0.80; 95% CI, 0.72 to 0.93; P < 0.001). The risk of postoperative hypotension was similar between the two groups (adjusted relative risk, 0.92; 95% CI, 0.77 to 1.10; P = 0.36). Results were consistent across the range of preoperative blood pressures. The practice of withholding angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers was only modestly correlated with patient characteristics and the type and timing of surgery. Conclusions: Withholding angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers before major noncardiac surgery was associated with a lower risk of death and postoperative vascular events. A large randomized trial is needed to confirm this finding. In the interim, clinicians should consider recommending that patients withhold angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers 24 h before surgery.

Accelerated care versus standard care among patients with hip fracture: the HIP ATTACK pilot trial

Background: A hip fracture causes bleeding, pain and immobility, and initiates inflammatory, hypercoagulable, catabolic and stress states. Accelerated surgery may improve outcomes by reducing the duration of these states and immobility. We undertook a pilot trial to determine the feasibility of a trial comparing accelerated care (i.e., rapid medical clearance and surgery) and standard care among patients with a hip fracture. Methods: Patients aged 45 years or older who, during weekday, daytime working hours, received a diagnosis of a hip fracture requiring surgery were randomly assigned to receive accelerated or standard care. Our feasibility outcomes included the proportion of eligible patients randomly assigned, completeness of follow-up and timelines of accelerated surgery. The main clinical outcome, assessed by data collectors and adjudicators who were unaware of study group allocations, was a major perioperative complication (i.e., a composite of death, preoperative myocardial infarction, myocardial injury after noncardiac surgery, pulmonary embolism, pneumonia, stroke, and life-threatening or major bleeding) within 30 days of randomization. Results: Of patients eligible for inclusion, 80% consented and were randomly assigned to groups (30 to accelerated care and 30 to standard care) at 2 centres in Canada and 1 centre in India. All patients completed 30-day follow-up. The median time from diagnosis to surgery was 6.0 hours in the accelerated care group and 24.2 hours in the standard care group (p < 0.001). A major perioperative complication occurred in 9 (30%) of the patients in the accelerated care group and 14 (47%) of the patients in the standard care group (hazard ratio 0.60, 95% confidence interval 0.26–1.39). Interpretation: These results show the feasibility of a trial comparing accelerated and standard care among patients with hip fracture and support a definitive trial. Trial registration: ClinicalTrials.gov, no. NCT01344343.