An algorithm to identify incident myocardial infarction using Medicaid data
Purpose Studies of non‐steroidal anti‐inflammatory drugs (NSAIDs) and cardiovascular events using administrative data require identification of incident acute myocardial infarctions (AMIs) and information on whether confounders differ by NSAID status. Methods We identified patients with a first AMI...
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Published in | Pharmacoepidemiology and drug safety Vol. 18; no. 11; pp. 1064 - 1071 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Chichester, UK
John Wiley & Sons, Ltd
01.11.2009
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Subjects | |
Online Access | Get full text |
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Summary: | Purpose
Studies of non‐steroidal anti‐inflammatory drugs (NSAIDs) and cardiovascular events using administrative data require identification of incident acute myocardial infarctions (AMIs) and information on whether confounders differ by NSAID status.
Methods
We identified patients with a first AMI hospitalization from Tennessee Medicaid files as those with primary ICD‐9 discharge diagnosis 410.x and hospitalization stay of > 2 calendar days. Eligible persons were non‐institutionalized, aged 50–84 years between 1999–2004, had continuous enrollment and no AMI, stroke, or non‐cardiovascular serious medical illness in the prior year. Of 5524 patients with a potential first AMI, a systematic sample (n = 350) was selected for review. Using defined criteria, we classified events using chest pain history, EKG, and cardiac enzymes, and calculated the positive predictive value (PPV) for definite or probable AMI.
Results
337 of 350 (96.3%) charts were ed and 307 (91.1%), 6 (1.8%), and 24 (7.1%) events were categorized as definite, probable, and no AMI, respectively. PPV for any definite or probable AMI was 92.8% (95% CI 89.6–95.2); for an AMI without an event in the past year 91.7% (95% CI 88.3–94.2), and for an incident AMI was 72.7% (95% CI 67.7–77.2). Age‐adjusted prevalence of current smoking (46.4% vs. 39.1%, p = 0.35) and aspirin use (36.9% vs. 35.9%, p = 0.90) was similar among NSAID users and non‐users
Conclusions
ICD‐9 code 410.x had high predictive value for identifying AMI. Among those with AMI, smoking and aspirin use was similar in NSAID exposure groups, suggesting these factors will not confound the relationship between NSAIDs and cardiovascular outcomes. Copyright © 2009 John Wiley & Sons, Ltd. |
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Bibliography: | istex:3ACF7A6CA844050FB419187BDB7F903E27F08007 This was an investigator initiated (Dr Griffin PI) study funded by Pfizer who had no role in the conduct of the study, collection of data, data management, or analysis. Pfizer scientists reviewed and commented on the overall protocol, but had no role in this manuscript. Dr Griffin reports receiving consulting fees from Merck Inc. Drs Choma, Griffin, and Roumie had full access to the data in the study and take responsibility for the integrity and the analysis of data. ArticleID:PDS1821 ark:/67375/WNG-JVK94FT2-6 |
ISSN: | 1053-8569 1099-1557 |
DOI: | 10.1002/pds.1821 |