Infectious Disease Consults of Pseudomonas aeruginosa Bloodstream Infection and Impact on Health Outcomes.

Background: Infectious diseases (ID) consultation improves health outcomes for certain infections but has not been well described for Pseudomonas aeruginosa (PA) bloodstream infection (BSI). Therefore, the goal of this study was to examine ID consultation of inpatients with PA BSI and factors impacting outcomes. Methods: This was a retrospective cohort study from January 1, 2012, to December 31, 2018, of adult hospitalized veterans with PA BSI and antibiotic treatment 2 days before through 5 days after the culture date. Multidrug-resistant (MDR) cultures were defined as cultures with resistance to at least 1 agent in ≥3 antimicrobial categories tested. Multivariable logistic regression models were fit to assess the impact of ID consults and adequate treatment on mortality. Results: A total of 3256 patients had PA BSI, of whom 367 (11.3%) were multidrug resistant (MDR). Most were male (97.5%), over 65 years old (71.2%), and White (70.9%). Nearly one-fourth (n = 784, 23.3%) died during hospitalization, and 870 (25.8%) died within 30 days of their culture. Adjusted models showed that ID consultation was associated with decreased in-hospital (odds ratio [OR], 0.47; 95% CI, 0.39-0.56) and 30-day mortality (OR, 0.51; 95% CI, 0.42-0.62). Conclusions: Consultation with ID physicians improves clinical outcomes such as in-hospital and 30-day mortality for patients with PA BSI. ID consultation provides value and should be considered for patients with PA BSI.

Clinician Conceptualization of the Benefits of Treatments for Individual Patients.

Importance: Knowing the expected effect of treatment on an individual patient is essential for patient care. Objective: To explore clinicians' conceptualizations of the chance that treatments will decrease the risk of disease outcomes. Design, Setting, and Participants: This survey study of attending and resident physicians, nurse practitioners, and physician assistants was conducted in outpatient clinical settings in 8 US states from June 2018 to November 2019. The survey was an in-person, paper, 26-item survey in which clinicians were asked to estimate the probability of adverse disease outcomes and expected effects of therapies for diseases common in primary care. Main Outcomes and Measures: Estimated chance that treatments would benefit an individual patient. Results: Of 723 clinicians, 585 (81%) responded, and 542 completed all the questions necessary for analysis, with a median (interquartile range [IQR]) age of 32 (29-44) years, 287 (53%) women, and 294 (54%) White participants. Clinicians consistently overestimated the chance that treatments would benefit an individual patient. The median (IQR) estimated chance that warfarin would prevent a stroke in the next year was 50% (5%-80%) compared with scientific evidence, which indicates an absolute risk reduction (ARR) of 0.2% to 1.0% based on a relative risk reduction (RRR) of 39% to 50%. The median (IQR) estimated chance that antihypertensive therapy would prevent a cardiovascular event within 5 years was 30% (10%-70%) vs evidence of an ARR of 0% to 3% based on an RRR of 0% to 28%. The median (IQR) estimated chance that bisphosphonate therapy would prevent a hip fracture in the next 5 years was 40% (10%-60%) vs evidence of ARR of 0.1% to 0.4% based on an RRR of 20% to 40%. The median (IQR) estimated chance that moderate-intensity statin therapy would prevent a cardiovascular event in the next 5 years was 20% (IQR 5%-50%) vs evidence of an ARR of 0.3% to 2% based on an RRR of 19% to 33%. Estimates of the chance that a treatment would prevent an adverse outcome exceeded estimates of the absolute chance of that outcome for 60% to 70% of clinicians. Clinicians whose overestimations were greater were more likely to report using that treatment for patients in their practice (eg, use of warfarin: correlation coefficient, 0.46; 95% CI, 0.40-0.53; P < .001). Conclusions and Relevance: In this survey study, clinicians significantly overestimated the benefits of treatment to individual patients. Clinicians with greater overestimates were more likely to report using treatments in actual patients.

Accuracy of Practitioner Estimates of Probability of Diagnosis Before and After Testing.

Importance: Accurate diagnosis is essential to proper patient care. Objective: To explore practitioner understanding of diagnostic reasoning. Design, Setting, and Participants: In this survey study, 723 practitioners at outpatient clinics in 8 US states were asked to estimate the probability of disease for 4 scenarios common in primary care (pneumonia, cardiac ischemia, breast cancer screening, and urinary tract infection) and the association of positive and negative test results with disease probability from June 1, 2018, to November 26, 2019. Of these practitioners, 585 responded to the survey, and 553 answered all of the questions. An expert panel developed the survey and determined correct responses based on literature review. Results: A total of 553 (290 resident physicians, 202 attending physicians, and 61 nurse practitioners and physician assistants) of 723 practitioners (76.5%) fully completed the survey (median age, 32 years; interquartile range, 29-44 years; 293 female [53.0%]; 296 [53.5%] White). Pretest probability was overestimated in all scenarios. Probabilities of disease after positive results were overestimated as follows: pneumonia after positive radiology results, 95% (evidence range, 46%-65%; comparison P < .001); breast cancer after positive mammography results, 50% (evidence range, 3%-9%; P < .001); cardiac ischemia after positive stress test result, 70% (evidence range, 2%-11%; P < .001); and urinary tract infection after positive urine culture result, 80% (evidence range, 0%-8.3%; P < .001). Overestimates of probability of disease with negative results were also observed as follows: pneumonia after negative radiography results, 50% (evidence range, 10%-19%; P < .001); breast cancer after negative mammography results, 5% (evidence range, <0.05%; P < .001); cardiac ischemia after negative stress test result, 5% (evidence range, 0.43%-2.5%; P < .001); and urinary tract infection after negative urine culture result, 5% (evidence range, 0%-0.11%; P < .001). Probability adjustments in response to test results varied from accurate to overestimates of risk by type of test (imputed median positive and negative likelihood ratios [LRs] for practitioners for chest radiography for pneumonia: positive LR, 4.8; evidence, 2.6; negative LR, 0.3; evidence, 0.3; mammography for breast cancer: positive LR, 44.3; evidence range, 13.0-33.0; negative LR, 1.0; evidence range, 0.05-0.24; exercise stress test for cardiac ischemia: positive LR, 21.0; evidence range, 2.0-2.7; negative LR, 0.6; evidence range, 0.5-0.6; urine culture for urinary tract infection: positive LR, 9.0; evidence, 9.0; negative LR, 0.1; evidence, 0.1). Conclusions and Relevance: This survey study suggests that for common diseases and tests, practitioners overestimate the probability of disease before and after testing. Pretest probability was overestimated in all scenarios, whereas adjustment in probability after a positive or negative result varied by test. Widespread overestimates of the probability of disease likely contribute to overdiagnosis and overuse.

Genotypic resistance testing creates new treatment challenges: two cases of oxacillin-susceptible methicillin-resistant Staphylococcus aureus.

Oxacillin-susceptible, mecA-positive Staphylococcus aureus isolates create a treatment challenge for the clinician. In this article, we describe two cases of bacteremia from isolates that carried the mecA gene but were susceptible to oxacillin (oxacillin-susceptible methicillin-resistant S. aureus [OS-MRSA]). DNA microarray analysis was used to characterize these isolates as a mecA-positive, clonal complex 5, pediatric strain and a mecA-positive, clonal complex 8, USA300 strain.