Staphylococcus aureus bacteremia in immunosuppressed patients: a multicenter, retrospective cohort study.

Staphylococcus aureus bacteremia (SAB) causes significant morbidity and mortality. We assessed the disease severity and clinical outcomes of SAB in patients with pre-existing immunosuppression, compared with immunocompetent patients. A retrospective cohort investigation studied consecutive patients with SAB hospitalized across six hospitals in Toronto, Canada from 2007 to 2010. Patients were divided into immunosuppressed (IS) and immunocompetent (IC) cohorts; the IS cohort was subdivided into presence of one and two or more immunosuppressive conditions. Clinical parameters were compared between cohorts and between IS subgroups. A competing risk model compared in-hospital mortality and time to discharge. A total of 907 patients were included, 716 (79%) were IC and 191 (21%) were IS. Within the IS cohort, 111 (58%) had one immunosuppressive condition and 80 (42%) had two or more conditions. The overall in-hospital mortality was 29%, with no differences between groups (IS 32%, IC 28%, p = 0.4211). There were no differences in in-hospital mortality (sub-distribution hazard ratio [sHR] 1.17, 95% confidence interval [CI] 0.88-1.56, p = 0.2827) or time to discharge (sHR 0.94, 95% CI 0.78-1.15, p = 0.5570). Independent mortality predictors for both cohorts included hypotension at 72 h (IS: p < 0.0001, IC: p < 0.0001) and early embolic stroke (IS: p < 0.0001, IC: p = 0.0272). Congestive heart failure was a mortality predictor in the IS cohort (p = 0.0089). Fever within 24 h (p = 0.0092) and early skin and soft tissue infections (p < 0.0001) were survival predictors in the IS cohort. SAB causes significant mortality regardless of pre-existing immune status, but immunosuppressed patients do not have an elevated risk of mortality relative to immunocompetent patients.

Insulin pump use compared with intravenous insulin during labour and delivery: the INSPIRED observational cohort study.

AIMS: To assess the safety and efficacy of pump therapy (continuous subcutaneous insulin infusion; CSII) during labour and delivery in women with Type 1 diabetes. METHODS: A retrospective cohort study of 161 consecutive Type 1 diabetic pregnancies delivered during 2000-2010 at Mount Sinai Hospital, Toronto, Canada. Capillary blood glucose levels during labour and delivery and time in/out of target (target: 4-6 mmol/l) were compared along with neonatal outcomes for three groups: (1) women on pumps who stayed on pumps during labour (pump/pump n = 31), (2) women on pumps who switched to intravenous (IV) insulin infusion during labour (pump/IVn = 25), and (3) women on multiple daily injections who switched to IV insulin infusion during labour (MDIn = 105). RESULTS: There were no significant differences between the mean or median glucose values during labour and delivery across all three groups, and no significant difference in time spent hypoglycaemic. However, women in the pump/pump group had significantly better glycaemic control as defined by mean glucose (5.5 vs. 6.4 mmol/l; P = 0.01), median glucose (5.4 vs. 6.3 mmol/l; P = 0.02), and more time spent in target (60.9% vs. 39.2%; P = 0.06) compared with women in the pump/IV group (after removing one outlier). CONCLUSIONS: This study demonstrates that the continuation of CSII therapy during labour and delivery appears safe and efficacious. Moreover, women who choose to continue CSII have better glucose control during delivery than those who switch to IV insulin, suggesting that it should be standard practice to allow women the option of continuing CSII during labour and delivery.

Clinical prediction rules in Staphylococcus aureus bacteremia demonstrate the usefulness of reporting likelihood ratios in infectious diseases.

Infectious diseases specialists often use diagnostic tests to assess the probability of a disease based on knowledge of the diagnostic properties. It has become standard for published studies on diagnostic tests to report sensitivity, specificity and predictive values. Likelihood ratios are often omitted. We compared published clinical prediction rules in Staphylococcus aureus bacteremia to illustrate the importance of likelihood ratios. We performed a narrative review comparing published clinical prediction rules used for excluding endocarditis in S. aureus bacteremia. Of nine published clinical prediction rules, only three studies reported likelihood ratios. Many studies concluded that the clinical prediction rule could safely exclude endocarditis based on high sensitivity and high negative predictive value. Of the studies with similar high sensitivity and high negative predictive value, calculated negative likelihood ratios were able to differentiate and identify the best clinical prediction rule for excluding endocarditis. Compared to sensitivity, specificity and predictive values, likelihood ratios can be more directly used to interpret diagnostic test results to assist in ruling in or ruling out a disease. Therefore, a new standard should be set to include likelihood ratios in reporting of diagnostic tests in infectious diseases research.