JAMA: U.S. posts shortest stays, highest MI readmission rate

In an effort to reduce healthcare costs, the U.S. has succeeded in getting the length of hospital stays for myocardial infarction (MI) down, but the tradeoff may be in higher readmission rates, according to a study that compared 30-day MI readmission rates in the U.S. and 16 other countries. The study in the Jan. 4 issue of the Journal of the American Medical Association found that patients in the U.S. had the shortest median length of stay but also had a 68 percent increased risk of being readmitted within a month.

Robb D. Kociol, MD, an advanced fellow in heart failure and transplant at Tufts Medical Center in Boston, and colleagues conducted a post-hoc analysis of 5,571 patients with ST-segment elevation MI (STEMI) who were enrolled in the Assessment of Pexelizumab in Acute MI trial between 2004 and 2006. Their objective was to study international variation in practice to identify predictors of 30-day readmission.

The primary endpoint was 30-day post-discharge all-cause hospital readmission and the secondary endpoint was 30-day post-discharge non-elective readmission, which excluded elective percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) surgery.

The researchers found that overall 11.3 percent of the patients were readmitted within 30 days. The U.S. had the highest rate, at 14.5 percent compared with 9.9 percent for all other countries.  When readmissions for elective PCI or CABG were excluded, the U.S. still had the highest rate, at 10.5 percent compared with 7.7 percent.

Sixty percent of patients in the U.S. remained in the hospital for three days or less while only 15.9 percent of patients in the other countries were discharged within that window. Slightly more than half of the patients in other countries stayed in the hospital for six days or more, compared with 16.6 percent of patients in the U.S.

Having multivessel disease was the strongest predictor of 30-day all-cause readmission, followed by being in the U.S. Patients with multivessel disease were almost twice as likely to be readmitted while U.S. patients had a 68 percent increased chance of being readmitted.

Even in an analysis that excluded elective readmissions, U.S. location remained an independent predictor of readmission. But after adjusting for country-level median length of stay, Kociol and colleagues reported U.S. location no longer was a predictor of all-cause or non-elective readmission.

“These data raise the possibility that higher readmission rates in the U.S. may be an adverse effect of the short LOS [length of stay] practice,” the authors wrote. “A consequence is that patients become eligible for readmission closer to the index event, when risk of subsequent events is still elevated. “

The authors acknowledged that despite their efforts to adjust for confounding factors, the country-level length of stay may reflect differences in practices across countries. They also noted that the trial from which they drew data used a selected patient population and may not be generalizable to a broader MI population.

“Our analysis shows that readmission maybe preventable because rates are nearly one-third lower in other countries, suggesting that the U.S. healthcare system has features that can be modified to decrease readmission rates,” they wrote. “Understanding these international differences may provide important insight into reducing such rates, particularly in the U.S.”

They cautioned more research should be done to ensure that efforts to balance index hospital stays and readmissions don’t adversely affect efficiency, outcomes or overall use of healthcare resources.