Eli N. Perencevich

Comparison of Mortality Associated with Methicillin-Resistant and Methicillin-Susceptible Staphylococcus aureus Bacteremia: A Meta-analysis

A meta-analysis was performed to summarize the impact of methicillin-resistance on mortality in Staphylococcus aureus bacteremia. A search of the MEDLINE database for studies published during the period of 1 January 1980 through 31 December 2000 and a bibliographic review identified English-language studies of S. aureus bacteremia. Studies were included if they contained the numbers of and mortality rates for patients with methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) bacteremia. Data were extracted on demographic characteristics of the patients, adjustment for severity and comorbid illness, source of bacteremia, and crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for in-hospital mortality. When the results were pooled with a random-effects model, a significant increase in mortality associated with MRSA bacteremia was evident (OR, 1.93; 95% CI, 1.54-2.42; P<.001); significant heterogeneity was present. We explored the reasons for heterogeneity by means of subgroup analyses. MRSA bacteremia is associated with significantly higher mortality rate than is MSSA bacteremia.

Health and economic impact of surgical site infections diagnosed after hospital discharge.

Although surgical site infections (SSIs) are known to cause substantial illness and costs during the index hospitalization, little information exists about the impact of infections diagnosed after discharge, which constitute the majority of SSIs. In this study, using patient questionnaire and administrative databases, we assessed the clinical outcomes and resource utilization in the 8-week postoperative period associated with SSIs recognized after discharge. SSI recognized after discharge was confirmed in 89 (1.9%) of 4,571 procedures from May 1997 to October 1998. Patients with SSI, but not controls, had a significant decline in SF-12 (Medical Outcomes Study 12-Item Short-Form Health Survey) mental health component scores after surgery (p=0.004). Patients required significantly more outpatient visits, emergency room visits, radiology services, readmissions, and home health aide services than did controls. Average total costs during the 8 weeks after discharge were US

The Use and Interpretation of Quasi-Experimental Studies in Medical Informatics

5,155 for patients with SSI and

Non-prescription antimicrobial use worldwide: a systematic review

1,773 for controls (p<0.001).

The Use and Interpretation of Quasi-Experimental Studies in Infectious Diseases

Quasi-experimental study designs, often described as nonrandomized, pre-post intervention studies, are common in the medical informatics literature. Yet little has been written about the benefits and limitations of the quasi-experimental approach as applied to informatics studies. This paper outlines a relative hierarchy and nomenclature of quasi-experimental study designs that is applicable to medical informatics intervention studies. In addition, the authors performed a systematic review of two medical informatics journals, the Journal of the American Medical Informatics Association (JAMIA) and the International Journal of Medical Informatics (IJMI), to determine the number of quasi-experimental studies published and how the studies are classified on the above-mentioned relative hierarchy. They hope that future medical informatics studies will implement higher level quasi-experimental study designs that yield more convincing evidence for causal links between medical informatics interventions and outcomes.

Adverse outcomes associated with contact precautions: A review of the literature

In much of the world antimicrobial drugs are sold without prescription or oversight by health-care professionals. The scale and effect of this practice is unknown. We systematically reviewed published works about non-prescription antimicrobials from 1970-2009, identifying 117 relevant articles. 35 community surveys from five continents showed that non-prescription use occurred worldwide and accounted for 19-100% of antimicrobial use outside of northern Europe and North America. Safety issues associated with non-prescription use included adverse drug reactions and masking of underlying infectious processes. Non-prescription use was common for non-bacterial disease, and antituberculosis drugs were available in many areas. Antimicrobial-resistant bacteria are common in communities with frequent non-prescription use. In a few settings, control efforts that included regulation decreased antimicrobial use and resistance. Non-prescription antimicrobial and antituberculosis use is common outside of North America and northern Europe and must be accounted for in public health efforts to reduce antimicrobial resistance.

Clinical and economic burden of antimicrobial resistance.

Quasi-experimental study designs, sometimes called nonrandomized, pre-post-intervention study designs, are ubiquitous in the infectious diseases literature, particularly in the area of interventions aimed at decreasing the spread of antibiotic-resistant bacteria. Little has been written about the benefits and limitations of the quasi-experimental approach. This article outlines a hierarchy of quasi-experimental study design that is applicable to infectious diseases studies and that, if applied, may lead to sounder research and more-convincing causal links between infectious diseases interventions and outcomes.

Fluoroquinolone Use and Clostridium difficile–Associated Diarrhea

BACKGROUND Contact Precautions (CP) are a standard method for preventing patient-to-patient transmission of multiple drug-resistant organisms (MDROs) in hospital settings. With the ongoing worldwide concern for MDROs including methicillin-resistant Staphylococcus aureus (MRSA) and broadened use of active surveillance programs, an increasing number of patients are being placed on CP. Whereas few would argue that CP are an important tool in infection control, many reports and small studies have observed worse noninfectious outcomes in patients on CP. However, no review of this literature exists. METHODS We systematically reviewed the literature describing adverse outcomes associated with CP. We identified 15 studies published between 1989 and 2008 relating to adverse outcomes from CP. Nine were higher quality based on standardized collection of data and/or inclusion of control groups. RESULTS Four main adverse outcomes related to CP were identified in this review. These included less patient-health care worker contact, changes in systems of care that produce delays and more noninfectious adverse events, increased symptoms of depression and anxiety, and decreased patient satisfaction with care. CONCLUSION Although CP are recommended by the Centers for Disease Control and Prevention as an intervention to control spread of MDROs, our review of the literature demonstrates that this approach has unintended consequences that are potentially deleterious to the patient. Measures to ameliorate these deleterious consequences of CP are urgently needed.

Control-Group Selection Importance in Studies of Antimicrobial Resistance: Examples Applied to Pseudomonas aeruginosa, Enterococci, and Escherichia coli

Knowledge of the clinical and economic impact of antimicrobial resistance is useful to influence programs and behavior in healthcare facilities, to guide policy makers and funding agencies, to define the prognosis of individual patients and to stimulate interest in developing new antimicrobial agents and therapies. There are a variety of important issues that must be considered when designing or interpreting studies into the clinical and economic outcomes associated with antimicrobial resistance. One of the most misunderstood issues is how to measure cost appropriately. Although imperfect, existing data show that there is an association between antimicrobial resistance in Staphylococcus aureus, enterococci and Gram-negative bacilli and increases in mortality, morbidity, length of hospitalization and cost of healthcare. Patients with infections due to antimicrobial-resistant organisms have higher costs (US

Comparative effectiveness of nafcillin or cefazolin versus vancomycin in methicillin-susceptible Staphylococcus aureus bacteremia

6000–30,000) than do patients with infections due to antimicrobial-susceptible organisms; the difference in cost is even greater when patients infected with antimicrobial-resistant organisms are compared with patients without infection. Given limited budgets, knowledge of the clinical and economic impact of antibiotic-resistant bacterial infections, coupled with the benefits of specific interventions targeted to reduce these infections, will allow for optimal control and improved patient safety. In this review, the authors discuss a variety of important issues that must be considered when designing or interpreting studies of the clinical and economic outcomes associated with antimicrobial resistance. Representative literature is reviewed regarding the associations between antimicrobial resistance in specific pathogens and adverse outcomes, including increased mortality, length of hospital stay and cost.