Biomedical subjects
Grant Innes
Publications and source records attributed to Grant Innes.
Clinical utility of novel cardiac markers: let the buyer beware.
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A clinical prediction rule for early discharge of patients with chest pain.
STUDY OBJECTIVE: Current risk stratification tools do not identify very-low-risk patients who can be safely discharged without prolonged emergency department (ED) observation, expensive rule-out protocols, or provocative testing. We seek to develop a clinical prediction rule applicable within 2 hours of ED arrival that would miss fewer than 2% of acute coronary syndrome patients and allow discharge within 2 to 3 hours for at least 30% of patients without acute coronary syndrome. METHODS: This prospective, cohort study enrolled consenting eligible subjects at least 25 years old at a single site. At 30 days, investigators assigned a diagnosis of acute coronary syndrome or no acute coronary syndrome according to predefined explicit definitions. A recursive partitioning model included risk factors, pain characteristics, physical and ECG findings, and cardiac marker results. RESULTS: Of 769 patients studied, 77 (10.0%) had acute myocardial infarction and 88 (11.4%) definite unstable angina. We derived a clinical prediction rule that was 98.8% sensitive and 32.5% specific. Patients have very low risk of acute coronary syndrome if they have a normal initial ECG, no previous ischemic chest pain, and age younger than 40 years. In addition, patients at least 40 years old and with a normal ECG result, no previous ischemic chest pain, and low-risk pain characteristics have very low risk if they have an initial creatine kinase-MB (CK-MB) less than 3.0 microg/L or an initial CK-MB greater than or equal to 3.0 microg/L but no ECG or serum-marker increase at 2 hours. CONCLUSION: The Vancouver Chest Pain Rule for early discharge defines a group of patients who can be safely discharged after a brief evaluation in the ED. Prospective validation is needed.
Safety and efficiency of emergency department assessment of chest discomfort.
BACKGROUND: Most Canadian emergency departments use an unstructured, individualized approach to patients with chest pain, without data to support the safety and efficiency of this practice. We sought to determine the proportions of patients with chest discomfort in emergency departments who either had acute coronary syndrome (ACS) and were inappropriately discharged from the emergency department or did not have ACS and were held for investigation. METHODS: Consecutive consenting patients aged 25 years or older presenting with chest discomfort to 2 urban tertiary care emergency departments between June 2000 and April 2001 were prospectively enrolled unless they had a terminal illness, an obvious traumatic cause, a radiographically identifiable cause, severe communication problems or no fixed address in British Columbia or they would not be available for follow-up by telephone. At 30 days we assigned predefined explicit outcome diagnoses: definite ACS (acute myocardial infarction [AMI] or definite unstable angina) or no ACS. RESULTS: Of 1819 patients, 241 (13.2%) were assigned a 30-day diagnosis of AMI and 157 (8.6%), definite unstable angina. Of these 398 patients, 21 (5.3%) were discharged from the emergency department without a diagnosis of ACS and without plans for further investigation. The clinical sensitivity for detecting ACS was 94.7% (95% confidence interval [CI] 92.5%- 96.9%) and the specificity 73.8% (95% CI 71.5%- 76.0%). Of the patients without ACS or an adverse event, 71.1% were admitted to hospital or held in the emergency department for more than 3 hours. INTERPRETATION: The current individualized approach to evaluation and disposition of patients with chest discomfort in 2 Canadian tertiary care emergency departments misses 5.3% of cases of ACS while consuming considerable health care resources for patients without coronary disease. Opportunities exist to improve both safety and efficiency.
Family practice residents' awareness of medical care costs in British Columbia.
BACKGROUND AND OBJECTIVES: Health economics continues to be an important issue, and past studies in the United States and Europe have found that physicians and physicians in training have a limited understanding of medical care costs. No medical care cost-awareness studies have been done in Canada. In this study, the costs of 46 commonly used diagnostic tests and therapeutics were determined, and family practice residents' awareness of these costs was assessed. METHODS: Ninety-seven first- and second-year residents of the University of British Columbia Family Practice Program were surveyed using the modified Dillman Total Design Method. Resident cost estimations were considered correct if within 25% or 50% of actual costs, and awareness was correlated with training location, gender, residency year, and importance ratings for ordering behavior. Degree of error was assessed by calculating median percent errors and confidence intervals for each therapeutic and diagnostic test. RESULTS: Costs were determined from the British Columbia Medical Association Guide to Fees, British Columbia Centre for Disease Control, hospital finance departments, and pharmaceutical wholesalers. A total of 82 (85%) residents completed the survey, but 11 were only partially completed. Few residents could estimate the cost of diagnostic tests or therapeutics to within 25% of the true cost, and the estimations were highly variable. Residents underestimated the cost of expensive drugs and overestimated the cost of inexpensive drugs. There was no relationship between cost awareness and training location, gender, residency year, or residents rating cost as important in ordering behaviour. CONCLUSION: Resident physicians in British Columbia, Canada have limited awareness of medical care costs.