Development and validation of a bedside risk score for MRSA among patients hospitalized with complicated skin and skin structure infections.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent cause of complicated skin and skin structure infections (cSSSI). Patients with MRSA require different empiric treatment than those with non-MRSA infections, yet no accurate tools exist to aid in stratifying the risk for a MRSA cSSSI. We sought to develop a simple bedside decision rule to tailor empiric coverage more accurately. METHODS: We conducted a large multicenter (N=62 hospitals) retrospective cohort study in a US-based database between April 2005 and March 2009. All adult initial admissions with ICD-9-CM codes specific to cSSSI were included. Patients admitted with MRSA vs. non-MRSA were compared with regard to baseline demographic, clinical and hospital characteristics. We developed and validated a model to predict the risk of MRSA, and compared its performance via sensitivity, specificity and other classification statistics to the healthcare-associated (HCA) infection risk factors. RESULTS: Of the 7,183 patients with cSSSI, 2,387 (33.2%) had MRSA. Factors discriminating MRSA from non-MRSA were age, African-American race, no evidence of diabetes mellitus, cancer or renal dysfunction, and prior history of cardiac dysrhythmia. The score ranging from 0 to 8 points exhibited a consistent dose-response relationship. A MRSA score of 5 or higher was superior to the HCA classification in all characteristics, while that of 4 or higher was superior on all metrics except specificity. CONCLUSIONS: MRSA is present in 1/3 of all hospitalized cSSSI. A simple bedside risk score can help discriminate the risk for MRSA vs. other pathogens with improved accuracy compared to the HCA definition.

Pattern of clopidogrel use in hospitalized patients receiving percutaneous coronary interventions.

PURPOSE: The pattern of clopidogrel loading in patients who had undergone percutaneous coronary intervention (PCI) was studied in a retrospective analysis of clinical records. METHODS: A database of deidentified electronic medical records from hospitals and hospital-affiliated outpatient facilities throughout the United States was analyzed for PCI patients with or without a diagnosis of acute coronary syndrome (ACS) who received clopidogrel loading doses of > or =300 mg between 48 hours before and 6 hours after PCI. A high dose was defined as > or =600 mg, and pretreatment was defined as more than 6 hours before PCI for 300-599 mg and 2 or more hours before PCI for > or =600 mg. RESULTS: Among 6253 PCI patients who met the criteria, there were 2331 with a diagnosis of ACS (ACS-PCI) and 3922 without an ACS diagnosis (elective PCI). Of the ACS-PCI patients, 1359 had ST-segment elevation myocardial infarction (STEMI) and 972 had unstable angina (UA) or non-ST-segment elevation myocardial infarction (NSTEMI). A majority of ACS-PCI patients (57%) received a > or =600-mg loading dose, 34% received a 300-mg loading dose, and the rest received a loading dose between 300 and 600 mg. Loading consisted of a single bolus in 75% of patients, two doses in 21.5%, and three or more doses in 3.1%. The first dose was during or after PCI in 56% of the UA/NSTEMI group and in 71% of both the elective PCI and STEMI groups. Among the UA/NSTEMI group, only 33% met criteria for pretreatment. CONCLUSION: Reported practice patterns of clopidogrel administration before PCI for UA/NSTEMI were not consistent with evidence generated from published clinical trials and guidelines. Recommended pre-treatment with clopidogrel was frequently not practiced.

Glucose normalization and outcomes in patients with acute myocardial infarction.

BACKGROUND: Elevated blood glucose levels on admission are associated with increased mortality in patients with acute myocardial infarction. Whether glucose normalization after admission is associated with improved survival remains controversial. In addition, whether outcomes differ in patients who have spontaneous resolution of hyperglycemia vs those who achieve normoglycemia after treatment with insulin is also unknown. METHODS: We studied 7820 hyperglycemic (admission glucose level, > or =140 mg/dL [to convert glucose to millimoles per liter, multiply by 0.0555]) patients with acute myocardial infarction hospitalized between January 1, 2000, and December 31, 2005, in 40 US hospitals. Patients were stratified according to their mean glucose levels after admission and were divided into those who did and did not receive insulin therapy. Multivariable logistic regression models were developed to examine whether lower glucose levels after admission are independently associated with better survival. Propensity-matching methods were then used to compare in-hospital mortality in patients who did and did not receive insulin therapy. RESULTS: After multivariable adjustment, lower mean postadmission glucose levels were associated with better survival (for mean postadmission glucose levels of 110 to <140, 140 to <170, 170 to <200, and > or =200 mg/dL, the odds ratios [95% confidence intervals] were 2.1 [1.3-3.5], 5.3 [3.0-8.6], 6.9 [4.1-11.4], and 13.0 [8.0-21.3], respectively, vs <110 mg/dL). Similar results were seen in patients who did and did not receive insulin therapy (P =.74 for insulin therapy x postadmission glucose level interaction). In propensity-matched analysis, mortality rates were similar between insulin-treated and non-insulin-treated patients across the spectrum of mean postadmission glucose levels (range, P = .15 to P = .91). CONCLUSIONS: Glucose normalization after admission is associated with better survival in hyperglycemic patients hospitalized with acute myocardial infarction whether or not they receive insulin therapy. A strategy of intentional glucose lowering with insulin therapy needs to be further tested in future randomized controlled trials.

Glucometrics in patients hospitalized with acute myocardial infarction: defining the optimal outcomes-based measure of risk.

BACKGROUND: Hyperglycemia on admission is associated with an increased mortality rate in patients with acute myocardial infarction. Whether metrics that incorporate multiple glucose assessments during acute myocardial infarction hospitalization are better predictors of mortality than admission glucose alone is not well defined. METHODS AND RESULTS: We evaluated 16,871 acute myocardial infarction patients hospitalized from January 2000 to December 2005. Using logistic regression models and C indexes, 3 metrics of glucose control (mean glucose, time-averaged glucose, hyperglycemic index), each evaluated over 3 time windows (first 24 hours, 48 hours, entire hospitalization), were compared with admission glucose for their ability to discriminate hospitalization survivors from nonsurvivors. Models were then used to evaluate the relationship between mean glucose and in-hospital mortality. All average glucose metrics performed better than admission glucose. The ability of models to predict mortality improved as the time window increased (C indexes for admission, mean 24 hours, 48 hours, and hospitalization glucose were 0.62, 0.64, 0.66, 0.70; P<0.0001). Statistically significant but small differences in C indexes of mean glucose, time-averaged glucose, and hyperglycemic index were seen. Mortality rates increased with each 10-mg/dL rise in mean glucose > or = 120 mg/dL (odds ratio, 1.8; P=0.003 for glucose 120 to < 130 mg/dL) and with incremental decline < 70 mg/dL (odds ratio, 6.4; P=0.01 versus glucose 100 to < 110 mg/dL). The slope of these relationships was steeper in patients without diabetes. CONCLUSIONS: Measures of persistent hyperglycemia during acute myocardial infarction are better predictors of mortality than admission glucose. Mean hospitalization glucose appears to be the most practical metric of hyperglycemia-associated risk. A J-shaped relationship exists between average glucose and mortality, with both persistent hyperglycemia and hypoglycemia associated with adverse prognosis.