January 4, 2012JAMA127 citationsOpen Access
International Variation in and Factors Associated With Hospital Readmission After Myocardial Infarction
Key Result
Hospitalization in the United States was associated with a significantly higher 30-day all-cause readmission rate after STEMI compared to other countries (14.5% vs 9.9%, OR 1.68), though this difference was attenuated after adjusting for length of stay.
Study Design
Type
Cohort (n=5,571)
Multicenter
Yes
Structured PICO
Does US location and care pattern increase 30-day readmission rates after STEMI compared to other countries?
P
Population
5,571 patients with STEMI who survived to hospital discharge (from an initial 5,745 enrolled in the APEX-AMI trial), multinational (296 sites in the United States, Canada, Australia, New Zealand, and 13 European countries).
I
Intervention
US location and care patterns (including shorter length of stay)
C
Comparator
Non-US location and care patterns (Canada, Australia, New Zealand, and 13 European countries)
O
Outcome
30-day postdischarge all-cause and nonelective readmissionshard clinical
Higher 30-day readmission rates after STEMI in the United States compared to other countries are largely explained by shorter initial hospital lengths of stay.
Main Result
Effect estimate: OR 1.68 (95% CI 1.37-2.07)
Absolute Event Rate: 14.5% vs 9.9%
p-value: p=<0.001
Limitations
- Retrospective analysis of clinical trial data with potential unmeasured or residual confounding
- Selected clinical trial population may not be generalizable to the STEMI population at large
- Some countries enrolled relatively few patients, limiting statistical power for comparisons
- Analysis of median length of stay was limited by the number of countries evaluated and included only as a linear predictor
- Compares only a small proportion of all countries globally, limiting true global interpretation
Abstract
CONTEXT: ST-segment elevation myocardial infarction (STEMI) treatment has improved outcomes and shortened hospital stay. Recently, 30-day readmission rates have been proposed as a metric for care of patients with STEMI. However, international rates and predictors of 30-day readmission after STEMI have not been studied. OBJECTIVE: To determine international variation in and predictors of 30-day readmission rates after STEMI and country-level care patterns. DESIGN, SETTING, AND PATIENTS: Post hoc analysis of the Assessment of Pexelizumab in Acute Myocardial Infarction trial that enrolled 5745 patients with STEMI at 296 sites in the United States, Canada, Australia, New Zealand, and 13 European countries from July 13, 2004, to May 11, 2006. Multivariable logistic regression analysis was used to identify independent predictors of all-cause and nonelective 30-day postdischarge readmission. MAIN OUTCOME MEASURES: Predictors of 30-day postdischarge all-cause and nonelective readmissions. RESULTS: Of 5571 patients with STEMI who survived to hospital discharge, 631 (11.3%) were readmitted within 30 days. Thirty-day readmission rates were higher for the United States than other countries (14.5% vs 9.9%; P < .001). Median length of stay was shortest for US patients (3 days; interquartile range, 2-4 days) and longest for Germany (8 days; interquartile range, 6-11 days). In multivariable regression, the predictors of 30-day readmission included multivessel disease (odds ratio OR, 1.97; 95% CI, 1.65-2.35) and US location (OR, 1.68; 95% CI, 1.37-2.07). Excluding elective readmission for revascularization, US enrollment was still an independent predictor of readmission (OR, 1.53; 95% CI, 1.20-1.96). After adjustment of the models for country-level median length of stay, US location was no longer an independent predictor of 30-day all-cause or nonelective readmission. Location in the United States was not a predictor of in-hospital death (OR, 0.88; 95% CI, 0.60-1.30) or 30-day postadmission death (OR, 1.0; 95% CI, 0.72-1.39). CONCLUSIONS: In this multinational study, there was variation across countries in 30-day readmission rates after STEMI, with readmission rates higher in the United States than in other countries. However, this difference was greatly attenuated after adjustment for length of stay.