CJEM Articles: Grant Innes

Objective: We sought to estimate the period prevalence of methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infection (SSTI) and evaluate risk factors for MRSA SSTI in an emergency department (ED) population.
Methods: We carried out a cohort study with a nested case-control design. Patients presenting to our ED with a wound culture and a discharge diagnosis of SSTI between January 2003 and September 2004 were dichotomized as MRSA positive or negative. Fifty patients with MRSA SSTI matched by calendar time to 100 controls with MRSA-negative SSTI had risk factors assessed using multivariate conditional logistic regression.
Results: Period prevalence of MRSA SSTI was 54.8% (95% confidence interval [CI] 50.2%-59.4%). The monthly period prevalence increased from 21% in January 2003 to 68% in September 2004 (p < 0.01). Risk factors for MRSA SSTI were injection drug use (IDU) (odds ratio [OR] 4.6, 95% CI 1.4-16.1), previous MRSA infection and colonization (OR 6.4, 95% CI 2.1-19.8), antibiotics in 8 weeks preceding index visit (OR 2.6, 95% CI 1.2-8.1), diabetes mellitus (OR 4.1, 95% CI 1.4-12.1), abscess (OR 5.6, 95% CI 1.8-17.1) and admission to hospital in previous 12 months (OR 2.6, 95% CI 1.1-11.2).
Conclusion: The period prevalence of MRSA SSTI between January 2003 and September 2004 was 54.8% at our institution. There was a marked increase in the monthly period prevalence from the beginning to the end of the study. Risk factors are IDU, previous MRSA infection and colonization, prescriptions for antibiotics in previous 8 weeks and admission to hospital in the preceding 12 months. On the basis of local prevalence and risk factor patterns, emergency physicians should consider MRSA as a causative agent for SSTI.

Background: Triage reliability studies typically use hypothetical scenarios and weighted kappa scores where agreement within one level is considered satisfactory. But if triage category is used to help define ED case-mix groups for comparative or benchmarking processes, agreement on exact triage level and major system involved is important. Our hypothesis was that a computerized menu that links presenting complaints to preferred triage levels (PC-linked triage) would provide high triage reliability.

Objectives: Our objective was to assess inter-rater reliability of PC-linked triage using the Canadian Emergency Department Triage and Acuity Scale (CTAS) in a real-time clinical setting, considering agreement on exact triage level and primary body system involved.

Methods: On duty triage nurses entered patient presenting complaint and PC-linked triage level as per standard procedure. In a convenience sample of patients, a second nurse, blinded to triage assignment, observed the triage interaction and independently entered presenting complaint and triage level on a dummy terminal.

Results: During the study, 15 nurse pairs triaged 266 patients. Study patients matched actual emergency department case mix closely. Triage nurses agreed exactly in 74% of cases and within one level in 94% of cases. The unweighted kappa value was 0.66 (95% confidence interval [CI], 0.60-0.73) and the quadratic weighted kappa value was 0.75 (95% CI, 0.68-0.81). Kappa for agreement on major system involved was 0.80 (95% CI, 0.69-0.91).

Conclusion: PC-linked triage has high inter-rater reliability in a real-time clinical setting. PC-linked triage may be useful as one factor in defining case-mix groups for benchmarking and comparative purposes.