Case Definitions for Acute Myocardial Infarction in Administrative Databases and Their Impact on In‐Hospital Mortality Rates

Objective

To identify validated ‐9‐/‐10 coded case definitions for acute myocardial infarction ().

Data Sources

Ovid Medline (1950–2010) was searched to identify studies that validated acute myocardial infarction () case definitions. Hospital discharge abstract data and chart data were linked to validate identified definitions.

Study Design

Systematic literature review, chart review, and administrative data analysis.

Data Collection/Extraction Methods

Data on sensitivity/specificity/positive and negative predictive values ( and ) were extracted from previous studies to identify validated case definitions for . These case definitions were validated in administrative data through chart review and applied to hospital discharge data to assess in‐hospital mortality.

Principal Findings

Of the eight ‐9‐ definitions validated in the literature, use of ‐9‐ code 410 to define had the highest sensitivity (94 percent) and specificity (99 percent). In our data, ‐9‐/‐10 codes 410/I21‐I22 in all available coding fields had high sensitivity (83.3 percent/82.8 percent) and (82.8 percent/82.2 percent). The in‐hospital mortality among patients identified using this case definition was 7.6 percent in ‐9‐ data and 6.6 percent in ‐10 data.

Conclusions

We recommend that ‐9‐ 410 or ‐10 I21‐I22 in the primary diagnosis coding field should be used to define . The use of a consistent validated case definition would improve comparability across studies