Risk adjustment using administrative data
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OBJECTIVES: To determine the frequency with which commonly coded clinical variables are complications, as opposed to baseline comorbidities, and to compare the results of 2 risk-adjusted outcome analyses for coronary artery bypass graft surgery for which we either (a) ignored, or (b) used the available “diagnosis-type indicator.”
DESIGN: Analysis of existing administrative data.
SETTING: Twenty-three Canadian hospitals.
PATIENTS: A total of 50,357 coronary artery bypass graft surgery cases.
MEASUREMENTS AND MAIN RESULTS: Among 21 clinical variables whose definitions involve the diagnosis-type indicator, 14 were predominantly (≥97%) baseline risk factors when present. Seven variables were often complication diagnoses: renal disease (when present, 13% coded as complications), recent myocardial infarction (15%), peptic ulcer disease (15%), congestive heart failure (17%), cerebrovascular disease (26%), hemiplegia (34%), and severe liver disease (35%). The results of risk adjustment analyses predicting in-hospital mortality differed when the diagnosis-type indicator was either used or ignored, and as a result, adjusted hospital mortality rates and rankings changed, often dramatically, with rankings increasing for 10 hospitals, decreasing for 9 hospitals, and remaining the same for only 4 hospitals.
CONCLUSIONS: The results of analyses performed using the diagnosis-type indicator in Canadian administrative data differ considerably from analyses that ignore the indicator. The widespread introduction of such an indicator should be considered in other countries, because risk-adjustment analyses performed without a diagnosis-type indicator may yield misleading results.
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- Risk adjustment using administrative data
Journal of General Internal Medicine
Volume 16, Issue 8 , pp 519-524
- Cover Date
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- administrative data
- risk adjustment
- coronary artery bypass graft surgery
- Industry Sectors
- Author Affiliations
- 1. Received from the Department of Medicine, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
- 2. the Department of Community Health Sciences, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada