Biomedical subjects

Matthew H Samore

Publications and source records attributed to Matthew H Samore.

42 records · Page 3Linked to original sources

PubMed2002

Control-group selection importance in studies of antimicrobial resistance: examples applied to Pseudomonas aeruginosa, Enterococci, and Escherichia coli.

We aimed to illustrate the importance of control-group selection on the results of risk factor analysis for (1) imipenem-resistant Pseudomonas aeruginosa, (2) vancomycin-resistant enterococci (VRE), and (3) ampicillin-sulbactam-resistant Escherichia coli. Case patients were compared with 2 different control groups: patients with the susceptible form of the organism (type 1), and control patients among whom the case patients arose during the same period as the case patients (type 2). Comparison of case patients who had imipenem-resistant P. aeruginosa with type-1 control patients identified use of imipenem (odds ratio [OR], 27.1) and quinolones (OR, 3.25) as a risk factor for selection of antimicrobial resistance, and comparison of the same case patients with type-2 control patients identified imipenem (OR, 6.34). When case patients with VRE were compared with type-1 and with type-2 control patients, use of vancomycin was identified as a risk factor (OR, 4.38 and 2.77, respectively). Comparison of case patients who had ampicillin-sulbactam-resistant E. coli compared with type-1 control patients identified ampicillin-sulbactam (OR, 2.71) and quinolones (OR, 2.72), and comparison with type-2 control patients identified ampicillin-sulbactam (OR, 1.68). The selection of control patients from the potentially suboptimal control type 1 can falsely identify certain antibiotics and overestimate the OR of the resistance-defining antibiotic.

Anti-Bacterial Agents↗

PubMed2002

An epidemiological investigation of a sustained high rate of pediatric parapneumonic empyema: risk factors and microbiological associations.

We investigated the increasing incidence of pediatric empyema during the 1990s at Primary Children's Medical Center in Salt Lake City. Of 540 children hospitalized with community-acquired bacterial pneumonia (CAP) who were discharged from 1 July 1993 through 1 July 1999, 153 (28.3%) had empyema. The annual population incidence of empyema increased during the study period from 1 to 5 cases per 100,000 population aged <19 years. Streptococcus pneumoniae was identified as the most common cause of CAP with or without empyema; serotype 1 accounted for 50% of the cases of pneumococcal empyema. Patients with empyema were more likely to be >3 years old, to have > or =7 days of fever, to have varicella, and to have received antibiotics and ibuprofen before admission to the hospital, compared with patients without empyema (P<.0001 for each factor). The increasing incidence of empyema was associated with infection due to S. pneumoniae serotype 1, outpatient treatment with certain antibiotics, ibuprofen use, and varicella.

Child↗

PubMed2002

Interventional study to evaluate the impact of an alcohol-based hand gel in improving hand hygiene compliance.

OBJECTIVE: To evaluate the effects of the introduction of an alcohol-based hand gel and multifaceted quality improvement (QI) interventions on hand hygiene (HH) compliance. DESIGN: Interventional, randomized cohort study with four study phases (baseline; limited intervention in two units; full intervention in three units; washout phase), performed in three intensive care units at a pediatric referral hospital. METHODS: During 724 thirty-minute daytime monitoring sessions, a nonidentified observer witnessed 12,216 opportunities for HH and recorded compliance. INTERVENTIONS: Introduction of an alcohol-based hand gel; multifaceted QI interventions (educational program, opinion leaders, performance feedback). RESULTS: Baseline compliance decreased after the first 2 weeks of observation from 42.5% to 28.2% (presumably because of waning of a Hawthorne effect), further decreased to 23.3% in the limited intervention phase and increased to 35.1% after the introduction of a hand gel with QI support in all three units (P < 0.001). The rise in compliance persisted in the last phase (compliance, 37.2%); however, a gradual decline was observed during the final weeks. Except for the limited intervention phase, compliance achieved through standard handwashing and glove use remained stable around 20 and 10%, respectively, whereas compliance achieved through gel use increased to 8% (P < 0.001). After adjusting for confounding, implementation of the hand gel with QI support remained significantly associated with compliance (odds ratio, 1.6; 95% confidence interval, 1.4 to 1.8). In a final survey completed by 62 staff members, satisfaction with the hand gel was modest (45%). CONCLUSIONS: We noted a statistically significant, modest improvement in compliance after introduction of an alcohol-based hand gel with multifaceted QI support. When appropriately implemented, alcohol-based HH may be effective in improving compliance.

Alcohols↗

PubMed2002

Antimicrobial use and antimicrobial resistance: a population perspective.

The need to stem the growing problem of antimicrobial resistance has prompted multiple, sometimes conflicting, calls for changes in the use of antimicrobial agents. One source of disagreement concerns the major mechanisms by which antibiotics select resistant strains. For infections like tuberculosis, in which resistance can emerge in treated hosts through mutation, prevention of antimicrobial resistance in individual hosts is a primary method of preventing the spread of resistant organisms in the community. By contrast, for many other important resistant pathogens, such as penicillin-resistant Streptococcus pneumoniae, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant Enterococcus faecium resistance is mediated by the acquisition of genes or gene fragments by horizontal transfer; resistance in the treated host is a relatively rare event. For these organisms, indirect, population-level mechanisms of selection account for the increase in the prevalence of resistance. These mechanisms can operate even when treatment has a modest, or even negative, effect on an individual host's colonization with resistant organisms.

Anti-Bacterial Agents↗

PubMed2002

Antecedent treatment with different antibiotic agents as a risk factor for vancomycin-resistant Enterococcus.

We conducted a matched case-control study to compare the effect of antecedent treatment with various antibiotics on subsequent isolation of vancomycin-resistant Enterococcus (VRE); 880 in-patients; 233 VRE cases, and 647 matched controls were included. After being matched for hospital location, calendar time, and duration of hospitalization, the following variables predicted VRE positivity: main admitting diagnosis; a coexisting condition (e.g., diabetes mellitus, organ transplant, or hepatobiliary disease); and infection or colonization with methicillin-resistant Staphylococcus aureus or Clostridium difficile within the past year (independent of vancomycin treatment). After controlling for these variables, we examined the effect of various antibiotics. Intravenous treatment with third-generation cephalosporins, metronidazole, and fluoroquinolones was positively associated with VRE. In our institution, when we adjusted the data for temporo-spatial factors, patient characteristics, and hospital events, treatment with third-generation cephalosporins, metronidazole, and fluoroquinolones was identified as a risk factor for VRE. Vancomycin was not a risk factor for isolation of VRE.

Adolescent↗

PubMedDate not supplied

Understanding keys to successful implementation of electronic decision support in rural hospitals: analysis of a pilot study for antimicrobial prescribing.

Electronic clinical decision support systems (CDSS) have been hailed for their potential to improve clinical outcomes. Using a pretest/posttest design, an Internet-based CDSS designed to optimize antimicrobial prescribing was pilot tested for community-acquired pneumonia in 5 rural hospitals in southwestern Idaho. An antimicrobial management team was created in each hospital to address clinicians' perception of excessive time required for direct use of the CDSS. In pooled hospital data, agreement with CDSS recommendations improved to a statistically significant level. However, inspection of data at the individual hospital level demonstrated that almost all improvement occurred in a single hospital. Failure in the other hospitals appeared to be primarily a consequence of organizational and cultural barriers. These barriers are discussed to understand keys for successful future implementation of CDSS in rural hospitals, drawing on experience with cultural barriers from other industries, specifically aviation.

Adult↗