Study design: Retrospective observational study.
Setting: All acute-care Veterans Affairs (VA) hospitals in the U.S.
Synopsis: A total of 4,124,907 index admissions were included in the final sample from all acute medical admissions in 129 acute-care VA hospitals from October 1996 to September 2010. The primary outcomes were the hospital LOS and the 30-day readmission rate. Index admissions for heart failure, chronic obstructive pulmonary disease (COPD), acute myocardial infarction (AMI), community-acquired pneumonia, and gastrointestinal hemorrhage were also analyzed separately.
The risk-adjusted analysis of LOS demonstrated significant reductions for all admissions over the 14-year period, to 3.98 days from 5.44 days, and for all of the individual conditions with reductions ranging from 1.40 days for gastrointestinal hemorrhage to 2.85 days for AMI. There were similar significant reductions in 30-day readmission rates for all admissions to 13.8% from 16.5% and within the individual conditions ranging from 0.9% in community-acquired pneumonia to 3.3% in COPD. These results show that the reductions in LOS did not increase the risk of readmissions. The major limitation of the study was that these data are only from a single healthcare system.
Bottom line: Data from VA hospitals show that reductions in LOS do not have adverse effects on 30-day readmission rates; instead, both LOS and readmission rates improved over the same time period.
Citation: Kaboli PJ, Go JT, Hockenberry J, et al. Associations between reduced hospital length of stay and 30-day readmission rate and mortality: 14-year experience in 129 Veterans Affairs hospitals. Ann Intern Med. 2012;157:837-845.
Better to Restrict Blood Transfusions in Acute Myocardial Infarction
Clinical question: Is a liberal or restrictive blood transfusion strategy better in patients with anemia and acute myocardial infarction?
Background: Patients with acute myocardial infarction (AMI) are often given therapies that can increase their risk for bleeding and anemia, and it is known that AMI patients have a worse prognosis if they have concomitant anemia. No clear consensus exists on the benefit or harm of blood transfusions in AMI patients.
Study design: Systematic review and meta-analysis.
Setting: Ten articles included in the qualitative and quantitative analyses out of 729 screened articles from Jan. 1, 1966, to March 31, 2012, using the search terms “transfusion,” “myocardial infarction,” and “mortality” in English language.
Synopsis: A total of 203,665 study participants were identified from the 10 studies (one randomized and nine observational) that met the inclusion and exclusion criteria. All-cause mortality was significantly higher in AMI patients who received a blood transfusion compared with those who did not (18.2% vs. 10.2%). However, this difference was not statistically significant in patients that had a STEMI or in patients with a baseline hematocrit less than 30%. A multivariate meta-regression with several covariates, excluding demographics, also showed that blood transfusion was associated with higher mortality and higher risk for subsequent myocardial infarction. There was significant heterogeneity in all results, but no single study was found as the source of the heterogeneity, and no significant publication bias was identified. The major limitations to this study are that there is a paucity of randomized trials available that pertain to this specific topic and the authors did not have patient-level covariates to include in their analyses.
Bottom line: There appears to be an increased risk of mortality and subsequent myocardial infarction in AMI patients who receive blood transfusions versus those who do not.
Citation: Chatterjee S, Wetterslev J, Sharma A, Lichstein E, Mukherjee D. Association of blood transfusion with increased mortality in myocardial infarction: a meta-analysis and diversity-adjusted study sequential analysis. JAMA Intern Med. 2013;173(2):132-139.