Carl van Walraven

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OBJECTIVE Adverse drug events (ADEs), defined as adverse patient outcomes caused by medications, are common and difficult to detect. Electronic detection of ADEs is a promising method to identify ADEs. We performed this systematic review to characterize established electronic detection systems and their accuracy. METHODS We identified studies evaluating(More)
OBJECTIVE Adverse events are poor health outcomes caused by medical care. Measuring them is necessary for quality improvements, but current detection methods are inadequate. We performed this study to validate a previously derived method of adverse event detection using term searching in physician-dictated discharge summaries. DESIGN This was a(More)
BACKGROUND Logistic regression models that incorporated age, sex, and indicator variables for the Johns Hopkins' Aggregated Diagnosis Groups (ADGs) categories have been shown to accurately predict all-cause mortality in adults. OBJECTIVES To develop 2 different point-scoring systems using the ADGs. The Mortality Risk Score (MRS) collapses age, sex, and(More)
BACKGROUND Predicting death risk in patients with diverse conditions is difficult. The Hospitalized-patient One-year Mortality Risk (HOMR) score accurately determines death risk in adults admitted to hospital using health administrative data unavailable to clinicians and most researchers. OBJECTIVE Determine if HOMR is valid when calculated using data(More)
Background and Purpose—Patients who are anticoagulated after cerebral ischemia have a 19-fold-higher risk of intracerebral hemorrhage (ICH) if they had an arterial rather than a cardiac source. To determine whether this excess risk of ICH was due to the underlying disease (cerebral ischemia of arterial versus cardiac origin) or whether it depended on the(More)
BACKGROUND Although peripheral nerve blocks decrease pain after total knee arthroplasty, the population-level impact of nerve blocks on arthroplasty resource utilization is unknown. METHODS We conducted a population-based cohort study using linked administrative data from Ontario, Canada. We identified all adults having their first primary knee(More)
Goal To ascertain outcomes of surveillance mammography (SM) following treatment of early stage unilateral primary breast cancer (PBC) in a population based case series. Methods Random samples from all 12,279 women having breast surgery within 4 months after diagnosis of PBC, between July 1991and December 1993 in Ontario, were drawn from a database created(More)
Background and Purpose—Stroke risk increases with age in patients who have nonvalvular atrial fibrillation. It is uncertain whether the efficacy of stroke prevention therapies in atrial fibrillation changes as patients age. The objective of this study was to determine the effect of age on the relative efficacy of oral anticoagulants (OAC) and antiplatelet(More)
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