National trends in patient safety for four common conditions, 2005-2011.

BACKGROUND: Changes in adverse-event rates among Medicare patients with common medical conditions and conditions requiring surgery remain largely unknown. METHODS: We used Medicare Patient Safety Monitoring System data abstracted from medical records on 21 adverse events in patients hospitalized in the United States between 2005 and 2011 for acute myocardial infarction, congestive heart failure, pneumonia, or conditions requiring surgery. We estimated trends in the rate of occurrence of adverse events for which patients were at risk, the proportion of patients with one or more adverse events, and the number of adverse events per 1000 hospitalizations. RESULTS: The study included 61,523 patients hospitalized for acute myocardial infarction (19%), congestive heart failure (25%), pneumonia (30%), and conditions requiring surgery (27%). From 2005 through 2011, among patients with acute myocardial infarction, the rate of occurrence of adverse events declined from 5.0% to 3.7% (difference, 1.3 percentage points; 95% confidence interval [CI], 0.7 to 1.9), the proportion of patients with one or more adverse events declined from 26.0% to 19.4% (difference, 6.6 percentage points; 95% CI, 3.3 to 10.2), and the number of adverse events per 1000 hospitalizations declined from 401.9 to 262.2 (difference, 139.7; 95% CI, 90.6 to 189.0). Among patients with congestive heart failure, the rate of occurrence of adverse events declined from 3.7% to 2.7% (difference, 1.0 percentage points; 95% CI, 0.5 to 1.4), the proportion of patients with one or more adverse events declined from 17.5% to 14.2% (difference, 3.3 percentage points; 95% CI, 1.0 to 5.5), and the number of adverse events per 1000 hospitalizations declined from 235.2 to 166.9 (difference, 68.3; 95% CI, 39.9 to 96.7). Patients with pneumonia and those with conditions requiring surgery had no significant declines in adverse-event rates. CONCLUSIONS: From 2005 through 2011, adverse-event rates declined substantially among patients hospitalized for acute myocardial infarction or congestive heart failure but not among those hospitalized for pneumonia or conditions requiring surgery. (Funded by the Agency for Healthcare Research and Quality and others.).

Chart-confirmed guillain-barre syndrome after 2009 H1N1 influenza vaccination among the Medicare population, 2009-2010.

Given the increased risk of Guillain-Barré Syndrome (GBS) found with the 1976 swine influenza vaccine, both active surveillance and end-of-season analyses on chart-confirmed cases were performed across multiple US vaccine safety monitoring systems, including the Medicare system, to evaluate the association of GBS after 2009 monovalent H1N1 influenza vaccination. Medically reviewed cases consisted of H1N1-vaccinated Medicare beneficiaries who were hospitalized for GBS. These cases were then classified by using Brighton Collaboration diagnostic criteria. Thirty-one persons had Brighton level 1, 2, or 3 GBS or Fisher Syndrome, with symptom onset 1-119 days after vaccination. Self-controlled risk interval analyses estimated GBS risk within the 6-week period immediately following H1N1 vaccination compared with a later control period, with additional adjustment for seasonality. Our results showed an elevated risk of GBS with 2009 monovalent H1N1 vaccination (incidence rate ratio = 2.41, 95% confidence interval: 1.14, 5.11; attributable risk = 2.84 per million doses administered, 95% confidence interval: 0.21, 5.48). This observed risk was slightly higher than that seen with previous seasonal influenza vaccines; however, additional results that used a stricter case definition (Brighton level 1 or 2) were not statistically significant, and our ability to account for preceding respiratory/gastrointestinal illness was limited. Furthermore, the observed risk was substantially lower than that seen with the 1976 swine influenza vaccine.

Racial disparities in the frequency of patient safety events: results from the National Medicare Patient Safety Monitoring System.

BACKGROUND: Although there is extensive evidence of racial disparities in processes and outcomes of medical care, there has been limited investigation of disparities in patient safety. OBJECTIVE: To determine whether there are racial disparities in the frequency of adverse events studied in the Medicare Patient Safety Monitoring System. DESIGN AND SUBJECTS: Abstraction of 102,623 randomly selected charts from hospital discharges of non-Hispanic white and black Medicare patients between January 1, 2004 and December 31, 2007 to assess frequency of patient safety events in 4 domains: general (pressure ulcers and falls), selected nosocomial infections, selected procedure-related adverse events, and adverse drug events due to anticoagulants and hypoglycemic agents. MEASURES: Racial disparities in risk of patient safety events, and differences in adverse event rates among hospital groups stratified by percentage of black patients. RESULTS: Blacks had higher adjusted risk than whites of suffering one of the measured nosocomial infections (1.34; 95% confidence interval, 1.17-1.55; P < 0.001) and one of the measured adverse drug events (1.29; 95% confidence interval, 1.19-1.40; P < 0.001). After adjustment for patient and hospital factors, patients in hospitals with the highest percentages of black patients were at increased risk of experiencing one of the measured nosocomial infections (1.9% vs. 1.5%; P < 0.001) and adverse drug events (8.7% vs. 7.8%; P < 0.01). CONCLUSIONS: Hospitalized blacks are at higher risk than whites of experiencing certain patient safety events. In addition, hospitals serving high percentages of black patients have higher risk-adjusted rates of selected patient safety events.

Identification of hospital-acquired catheter-associated urinary tract infections from Medicare claims: sensitivity and positive predictive value.

BACKGROUND AND OBJECTIVE: Hospital-acquired catheter-associated urinary tract infection (CAUTI) is one of the first 6 conditions Medicare is targeting to reduce payment associated with hospital-acquired conditions under Congressional mandate. This study was to determine the positive predictive value (PPV) and sensitivity in identifying patients in Medicare claims who had urinary catheterization and who had hospital-acquired CAUTIs. RESEARCH DESIGN: CAUTIs identified by ICD-9-CM codes in Medicare claims were compared with those revealed by medical record abstraction in random samples of Medicare discharges in 2005 to 2006. Hospital discharge abstracts (2005) from the states of New York and California were used to estimate the potential impact of a present-on-admission (POA) indicator on PPV. RESULTS: ICD-9-CM procedure codes for urinary catheterization appeared in only 1.4% of Medicare claims for patients who had urinary catheters. As a proxy, claims with major surgery had a PPV of 75% and sensitivity of 48%, and claims with any surgical procedure had a PPV of 53% and sensitivity of 79% in identifying urinary catheterization. The PPV and sensitivity for identifying hospital-acquired CAUTIs varied, with the PPV at 30% and sensitivity at 65% in claims with major surgery. About 80% of the secondary diagnosis codes indicating UTIs were flagged as POA, suggesting that the addition of POA indicators in Medicare claims would increase PPV up to 86% and sensitivity up to 79% in identifying hospital-acquired CAUTIs. CONCLUSIONS: The validity in identifying urinary catheter use and CAUTIs from Medicare claims is limited, but will be increased substantially upon addition of a POA indicator.

Hospital-acquired pressure ulcers: results from the national Medicare Patient Safety Monitoring System study.

OBJECTIVES: To determine the national and state incidence levels of newly hospital-acquired pressure ulcers (PUs) in Medicare beneficiaries and to describe the clinical and demographic characteristics and outcomes of these individuals. DESIGN: Retrospective secondary analysis of the national Medicare Patient Safety Monitoring System (MPSMS) database. SETTING: Medicare-eligible hospitals across the United States and select territories. PARTICIPANTS: Fifty-one thousand eight hundred forty-two randomly selected hospitalized fee-for-service Medicare beneficiaries discharged from the hospital between January 1, 2006, and December 31, 2007. MEASUREMENTS: Data were abstracted from the MPSMS, which collects information on multiple hospital adverse events. RESULTS: Of the 51,842 individuals in the MPSMS 2006/07 sample, 2,313 (4.5%) developed at least one new PU during their hospitalization. The mortality risk-adjusted odds ratios were 2.81 (95% confidence interval (CI) = 2.44-3.23) for in-hospital mortality, 1.69 (95% CI=1.61-1.77) for mortality within 30 days after discharge, and 1.33 (95% CI = 1.23-1.45) for readmission within 30 days. The hospital risk-adjusted main length of stay was 4.8 days (95% CI = 4.7-5.0 days) for individuals who did not develop PUs and 11.2 days (95% CI = 10.19-11.4) for those with hospital-acquired PUs (P < .001). The Northeast region and Missouri had the highest incidence rates (4.6% and 5.9%, respectively). CONCLUSION: Individuals who developed PUs were more likely to die during the hospital stay, have generally longer hospital lengths of stay, and be readmitted within 30 days after discharge.

Evaluation of Guillain-Barré Syndrome among recipients of influenza vaccine in 2000 and 2001.

BACKGROUND: The 1976-1977 swine influenza vaccine was associated with an elevated risk of Guillain-Barré Syndrome (GBS), especially within 6 weeks after vaccination. A 2004 IOM report concluded that evidence was inadequate to accept or reject a causal relationship between subsequent influenza vaccine formulations and GBS. Studies published after the IOM report have been limited by passively reported data or lack of validation of coded diagnoses. PURPOSE: To evaluate whether influenza vaccine is associated with GBS. METHODS: Controlled observational study using national data from the Medicare program, which ensures a predominantly elderly population. People included had a Medicare claim for influenza vaccination during September-December in 2000 or 2001. Medical records were reviewed to classify definite, probable, or possible GBS (or not a case) using a standardized case definition. In a risk interval design, the incidence rate of GBS during Weeks 0-6 after vaccination (exposed period) was compared to Weeks 9-14 after vaccination (comparison period). Data collection occurred during 2003-2007, and analysis was conducted during 2007-2009. RESULTS: Primary analysis included 22.2 million vaccinees, among whom 164 definite or probable GBS cases with onset during Weeks 0-6 or 9-14 were identified. The incidence rate ratio (IRR [95% CIs]) based on the GBS rate in the vaccine-exposed versus comparison periods, was 1.04 (0.76, 1.43) for combined years; 0.86 (0.52, 1.41) among people vaccinated in 2000; and 1.21 (0.79, 1.86) among people vaccinated in 2001. Secondary analysis additionally included 74 possible GBS cases; results were similar. CONCLUSIONS: Overall, the results do not support an association between influenza vaccine receipt and GBS among the elderly for the years studied (2000-2001 and 2001-2002 formulations).