Hien H. Nguyen

Overdiagnosis of Clostridium difficile Infection in the Molecular Test Era

IMPORTANCE Clostridium difficile is a major cause of health care-associated infection, but disagreement between diagnostic tests is an ongoing barrier to clinical decision making and public health reporting. Molecular tests are increasingly used to diagnose C difficile infection (CDI), but many molecular test-positive patients lack toxins that historically defined disease, making it unclear if they need treatment. OBJECTIVE To determine the natural history and need for treatment of patients who are toxin immunoassay negative and polymerase chain reaction (PCR) positive (Tox-/PCR+) for CDI. DESIGN, SETTING, AND PARTICIPANTS Prospective observational cohort study at a single academic medical center among 1416 hospitalized adults tested for C difficile toxins 72 hours or longer after admission between December 1, 2010, and October 20, 2012. The analysis was conducted in stages with revisions from April 27, 2013, to January 13, 2015. MAIN OUTCOMES AND MEASURES Patients undergoing C difficile testing were grouped by US Food and Drug Administration-approved toxin and PCR tests as Tox+/PCR+, Tox-/PCR+, or Tox-/PCR-. Toxin results were reported clinically. Polymerase chain reaction results were not reported. The main study outcomes were duration of diarrhea during up to 14 days of treatment, rate of CDI-related complications (ie, colectomy, megacolon, or intensive care unit care) and CDI-related death within 30 days. RESULTS Twenty-one percent (293 of 1416) of hospitalized adults tested for C difficile were positive by PCR, but 44.7% (131 of 293) had toxins detected by the clinical toxin test. At baseline, Tox-/PCR+ patients had lower C difficile bacterial load and less antibiotic exposure, fecal inflammation, and diarrhea than Tox+/PCR+ patients (P < .001 for all). The median duration of diarrhea was shorter in Tox-/PCR+ patients (2 days; interquartile range, 1-4 days) than in Tox+/PCR+ patients (3 days; interquartile range, 1-6 days) (P = .003) and was similar to that in Tox-/PCR- patients (2 days; interquartile range, 1-3 days), despite minimal empirical treatment of Tox-/PCR+ patients. No CDI-related complications occurred in Tox-/PCR+ patients vs 10 complications in Tox+/PCR+ patients (0% vs 7.6%, P < .001). One Tox-/PCR+ patient had recurrent CDI as a contributing factor to death within 30 days vs 11 CDI-related deaths in Tox+/PCR+ patients (0.6% vs 8.4%, P = .001). CONCLUSIONS AND RELEVANCE Among hospitalized adults with suspected CDI, virtually all CDI-related complications and deaths occurred in patients with positive toxin immunoassay test results. Patients with a positive molecular test result and a negative toxin immunoassay test result had outcomes that were comparable to patients without C difficile by either method. Exclusive reliance on molecular tests for CDI diagnosis without tests for toxins or host response is likely to result in overdiagnosis, overtreatment, and increased health care costs.

Prophylactic Antibiotics in Hip and Knee Arthroplasty

Prophylactic parenteral antibiotics have contributed to the present low rate of surgical site infections following hip and knee arthroplasty. Over the past decade, there has been a change in the pattern of methicillin-resistant Staphylococcus aureus infections from hospital-acquired to community-acquired. The findings of recent studies on screening programs to identify carriers of methicillin-resistant Staphylococcus aureus have been equivocal, with some studies showing that such programs reduce the rate of infections and others showing no effect on infection rates. Hospitals with antibiogram data that reveal high Staphylococcus resistance should consider use of vancomycin as a prophylactic antibiotic.

Acute Bacterial Skin and Skin Structure Infections (ABSSSI): Practice Guidelines for Management and Care Transitions in the Emergency Department and Hospital

BACKGROUND Acute bacterial skin and skin structure infections (ABSSSI), formally referred to as complicated skin and soft tissue infections, include infections with resistance to previously effective antimicrobials. Increasing dramatically in incidence, they have become a challenging medical problem associated with high direct and indirect costs to both the medical system and society. OBJECTIVES To describe the burden of ABSSSI and to explore multidisciplinary approaches to its management and new treatments that can be initiated in the emergency department. DISCUSSION We offer a best practice model aimed at providing risk-stratified and convenient care for ABSSSI at the lowest possible cost, while minimizing complications, readmissions, and inappropriate antibiotic use. In doing so, we focus on the care provided by emergency physicians and hospitalists and the transition of management between them for inpatient care, as well as the facilitation of observation or direct-to-outpatient care for suitable patients. CONCLUSIONS A standard, consistent, and multidisciplinary approach to ABSSSI can streamline care, reduce admissions, support antimicrobial stewardship, and improve clinical and resource consumption outcomes.

Synergies and Distinctions between Computational Disciplines in Biomedical Research: Perspective from the Clinical and Translational Science Award Programs

Clinical and translational research increasingly requires computation. Projects may involve multiple computationally oriented groups including information technology (IT) professionals, computer scientists, and biomedical informaticians. However, many biomedical researchers are not aware of the distinctions among these complementary groups, leading to confusion, delays, and suboptimal results. Although written from the perspective of Clinical and Translational Science Award (CTSA) programs within academic medical centers, this article addresses issues that extend beyond clinical and translational research. The authors describe the complementary but distinct roles of operational IT, research IT, computer science, and biomedical informatics using a clinical data warehouse as a running example. In general, IT professionals focus on technology. The authors distinguish between two types of IT groups within academic medical centers: central or administrative IT (supporting the administrative computing needs of large organizations) and research IT (supporting the computing needs of researchers). Computer scientists focus on general issues of computation such as designing faster computers or more efficient algorithms, rather than specific applications. In contrast, informaticians are concerned with data, information, and knowledge. Biomedical informaticians draw on a variety of tools, including but not limited to computers, to solve information problems in health care and biomedicine. The paper concludes with recommendations regarding administrative structures that can help to maximize the benefit of computation to biomedical research within academic health centers.

Costs of needlestick injuries and subsequent hepatitis and HIV infection

ABSTRACT Background: Physicians, nurses and other healthcare workers (HCWs) are at risk of bloodborne pathogens infection from needlestick injuries, but costs of needlesticks are little studied. Methods: We used the cost-of-illness and incidence approaches. We used the perspective of the medical provider (medical costs) and the individual (lost productivity). Data on needlesticks, infections from hepatitis B and C (HBV, HCV) and human immune-deficiency (HIV) among HCWs, as well as data on per-unit costs were culled from research literature, Centers for Disease Control and Prevention reports, and Bureau of Labor Statistics reports. We also generated estimates based upon industry employment and scenarios for source-patients. These data and estimates were combined with assumptions to produce a model that generated base-case estimates as well as one-way and multi-way probabilistic sensitivity analyses. Future costs were discounted by 3%. Results: We estimated 644 963 needlesticks in the healthcare industry for 2004 of which 49% generated costs. Medical costs were

Hospitalist to Home: Outpatient Parenteral Antimicrobial Therapy at an Academic Center

107.3 million of which 96% resulted from testing and prophylaxis and 4% from treating long-term infections (34 persons with chronic HBV, 143 with chronic HCV, and 1 with HIV). Lost-work productivity generated

Injecting drug use and community-associated methicillin-resistant Staphylococcus aureus infection

81.2 million, for which 59% involved testing and prophylaxis and 41% involved long-term infections. Combined medical and work productivity costs summed to

Derivation and validation of a clinical prediction score for isolation of inpatients with suspected pulmonary tuberculosis.

188.5 million. Multi-way sensitivity analysis suggested a range on combined costs from

Implementing a Web-based Information Resource at an Inner-city Community Church: Lessons Learned

100.7 million to

Treatments for Hepatitis B

405.9 million. Conclusion: Detailed methodology was developed to estimate costs of needlesticks and subsequent infections for hospital-based and non-hospital-based health care workers. The combined medical and lost productivity costs comprised roughly 0.1% of all occupational injury and illness costs for all jobs in the economy. We did not account for lost home production or pain and suffering costs, however, nor did we estimate benefit/cost ratios of specific interventions to reduce needlesticks.