Browsing by Author "McRae, Andrew D."

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    Development of a Clinical Care Pathway for Patients with Suspected Acute Coronary Syndromes in the Emergency Department
    (2020-04-30) O'Rielly, Connor M.; McRae, Andrew D.; Ronksley, Paul Everett; Andruchow, James E.; Sajobi, Tolulope T.
    Chest pain is a predominant reason for emergency department (ED) visits and hospitalizations in Canada. ED physicians use diagnostic tools (e.g., biomarkers) to identify patients with myocardial infarction (MI) requiring intervention, and prognostic tools (e.g., risk scores) to determine which patients without MI are eligible for discharge. While clinical guidelines recommend that these two portions of the assessment occur sequentially, the evidence for each has emerged in isolation. There is also a paucity of evidence on risk score use in the era of high-sensitivity cardiac troponin (hs-cTn) assays, adverse event risk factors for patients without MI, and appropriate timelines for follow-up. This project had three complimentary objectives: (1) Synthesize available evidence on prognostic prediction score performance when hs-cTn assays are incorporated; (2) Quantify the time course of major adverse cardiac events (MACE) in patients without index MI and identify characteristics with potential predictive value for MACE, and; (3) Develop a sequential clinical pathway for the assessment of chest pain in the ED and measure the impacts on diagnostic and prognostic accuracy as well as ED patient flow. A systematic review was conducted to synthesize evidence on the chest pain risk scores to be prioritized for integration into the clinical pathway. A time-to-event analysis was then conducted to measure timing of MACE in patients without index MI, as well as a stratified analysis to identify characteristics with predictive value for 30-day MACE to be used in the pathway for clinical stratification. Trial clinical pathways were developed and quantitatively compared. Pathways combined a validated 2-hour hs-cTn diagnostic algorithm with variable clinical pre-stratification, risk score types, and low-risk cut-offs. A sequential clinical pathway using a validated hs-cTn algorithm and the HEART score can identify nearly 40% of ED chest pain patients as eligible for discharge without the need for further testing with no missed MI or 30-day MACE. This thesis project contributed evidence necessary for the updating and advancing of the ED chest pain assessment and presents an evidence-based sequential clinical pathway that maximizes the efficiency of the ED chest pain assessment.
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    Passive Surveillance of Transient Ischemic Attacks in the Emergency Department: Validity of Administrative Data and Determinants of Inaccuracies in Data Coding
    (2016) Yu, Amy Y. X.; Hill, Michael D.; Coutts, Shelagh B.; Quan, Hude; McRae, Andrew D.
    Stroke is a leading cause of morbidity and transient ischemic attacks (TIA) are an ideal target for stroke prevention strategies. Administrative data are an important source of information for TIA research, but they have not been validated in the emergency department (ED). We aimed to determine the validity of TIA codes in the Canadian ED administrative database and the predictors of accurate TIA coding. We studied patients presenting to the ED with acute neurological symptoms. The National Ambulatory Care Reporting System (NACRS) database diagnosis codes were compared to the ED chart re-abstraction and 90-day final clinical diagnoses to obtain the sensitivity, specificity, and predictive values. The sensitivity of TIA codes was low to moderate (37-64%), but the specificity was high (82-93%). Quality of physician documentation was an important predictor of data accuracy. Our findings inform TIA research and surveillance methods and we identify an opportunity for improving administrative data quality.
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    Transitions in health care settings for frequent and infrequent users of emergency departments: a population-based retrospective cohort study
    (2023-11-14) Rosychuk, Rhonda J.; Chen, Anqi A.; Ospina, Maria B.; McRae, Andrew D.; Hu, X. Joan; McLane, Patrick
    Abstract Background Efforts to reduce emergency department (ED) volumes often target frequent users. We examined transitions in care across ED, hospital, and community settings, and in-hospital death, for high system users (HSUs) compared to controls. Methods Population-based databases provided ED visits and hospitalizations in Alberta and Ontario, Canada. The retrospective cohort included the top 10% of all the ED users during 2015/2016 (termed HSUs) and a random sample of controls (4 per each HSU) from the bottom 90% per province. Rates of transitions among ED, hospitalization, community settings, and in-hospital mortality were adjusted for sociodemographic and ED variables in a multistate statistical model. Results There were 2,684,924 patients and 579,230 (21.6%) were HSUs. Patient characteristics associated with shorter community to ED transition times for HSUs included Alberta residence (ratio of hazard ratio [RHR] = 1.11, 95% confidence interval [CI] 1.11,1.12), living in areas in the lower income quintile (RHR = 1.06, 95%CI 1.06,1.06), and Ontario residents without a primary health care provider (RHR = 1.13, 95%CI 1.13,1.14). Once at the ED, characteristics associated with shorter ED to hospital transition times for HSUs included higher acuity (e.g., RHR = 1.70, 95% CI 1.61, 1.81 for emergent), and for many diagnoses including chest pain (RHR = 1.71, 95%CI 1.65,1.76) and gastrointestinal (RHR = 1.66, 95%CI 1.62,1.71). Once admitted to hospital, HSUs did not necessarily have longer stays except for conditions such as chest pain (RHR = 0.90, 95% CI 0.86, 0.95). HSUs had shorter times to death in the ED if they presented for cancer (RHR = 2.51), congestive heart failure (RHR = 1.93), myocardial infarction (RHR = 1.53), and stroke (RHR = 1.84), and shorter times to death in-hospital if they presented with cancer (RHR = 1.29). Conclusions Differences between HSUs and controls in predictors of transitions among care settings were identified. Co-morbidities and limitations in access to primary care are associated with more rapid transitions from community to ED and hospital among HSUs. Interventions targeting these challenges may better serve patients across health systems.. Trial registration Not applicable.