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Biomedical subjects

K G Shojania

Publications and source records attributed to K G Shojania.

9 recordsLinked to original sources
PubMed2005

Overestimation of clinical diagnostic performance caused by low necropsy rates.

BACKGROUND: Diagnostic sensitivity is calculated as the number of correct diagnoses divided by the sum of correct diagnoses plus the number of missed or false negative diagnoses. Because missed diagnoses are generally detected during clinical follow up or at necropsy, the low necropsy rates seen in current practice may result in overestimates of diagnostic performance. Using three target conditions (aortic dissection, pulmonary embolism, and active tuberculosis), the prevalence of clinically missed cases among necropsied and non-necropsied deaths was estimated and the impact of low necropsy rates on the apparent sensitivity of antemortem diagnosis determined. METHODS: After reviewing case series for each target condition, the most recent study that included cases first detected at necropsy was selected and the reported sensitivity of clinical diagnosis adjusted by estimating the total number of cases that would have been detected had all decedents undergone necropsy. These estimates were based on available data for necropsy rates, time period, country (US v non-US), and case mix. RESULTS: For all three target diagnoses, adjusting for the estimated prevalence of clinically missed cases among non-necropsied deaths produced sensitivity values outside the 95% confidence interval for the originally reported values, and well below sensitivities reported for the diagnostic tests that are usually used to detect these conditions. For active tuberculosis the sensitivity of antemortem diagnosis decreased from an apparent value of 96% to a corrected value of 83%, with a plausible range of 42-91%; for aortic dissection the sensitivity decreased from 86% to 74%; and for pulmonary embolism the reduction fell only modestly from 97% to 91% but was still lower than generally reported values of 98% or more. CONCLUSIONS: Failure to adjust for the prevalence of missed cases among non-necropsied deaths may substantially overstate the performance of diagnostic tests and antemortem diagnosis in general, especially for conditions with high early case fatality.

Aortic Dissection↗
PubMed2001

Making health care safer: a critical analysis of patient safety practices.

OBJECTIVES: Patient safety has received increased attention in recent years, but mostly with a focus on the epidemiology of errors and adverse events, rather than on practices that reduce such events. This project aimed to collect and critically review the existing evidence on practices relevant to improving patient safety. SEARCH STRATEGY AND SELECTION CRITERIA: Patient safety practices were defined as those that reduce the risk of adverse events related to exposure to medical care across a range of diagnoses or conditions. Potential patient safety practices were identified based on preliminary surveys of the literature and expert consultation. This process resulted in the identification of 79 practices for review. The practices focused primarily on hospitalized patients, but some involved nursing home or ambulatory patients. Protocols specified the inclusion criteria for studies and the structure for evaluation of the evidence regarding each practice. Pertinent studies were identified using various bibliographic databases (e.g., MEDLINE, PsycINFO, ABI/INFORM, INSPEC), targeted searches of the Internet, and communication with relevant experts. DATA COLLECTION AND ANALYSIS: Included literature consisted of controlled observational studies, clinical trials and systematic reviews found in the peer-reviewed medical literature, relevant non-health care literature and "gray literature." For most practices, the project team required that the primary outcome consist of a clinical endpoint (i.e., some measure of morbidity or mortality) or a surrogate outcome with a clear connection to patient morbidity or mortality. This criterion was relaxed for some practices drawn from the non-health care literature. The evidence supporting each practice was summarized using a prospectively determined format. The project team then used a predefined consensus technique to rank the practices according to the strength of evidence presented in practice summaries. A separate ranking was developed for research priorities. MAIN RESULTS: Practices with the strongest supporting evidence are generally clinical interventions that decrease the risks associated with hospitalization, critical care, or surgery. Many patient safety practices drawn primarily from nonmedical fields (e.g., use of simulators, bar coding, computerized physician order entry, crew resource management) deserve additional research to elucidate their value in the health care environment. The following 11 practices were rated most highly in terms of strength of the evidence supporting more widespread implementation. Appropriate use of prophylaxis to prevent venous thromboembolism in patients at risk; Use of perioperative beta-blockers in appropriate patients to prevent perioperative morbidity and mortality; Use of maximum sterile barriers while placing central intravenous catheters to prevent infections; Appropriate use of antibiotic prophylaxis in surgical patients to prevent postoperative infections; Asking that patients recall and restate what they have been told during the informed consent process; Continuous aspiration of subglottic secretions (CASS) to prevent ventilator-associated pneumonia; Use of pressure relieving bedding materials to prevent pressure ulcers; Use of real-time ultrasound guidance during central line insertion to prevent complications; Patient self-management for warfarin (Coumadin) to achieve appropriate outpatient anticoagulation and prevent complications; Appropriate provision of nutrition, with a particular emphasis on early enteral nutrition in critically ill and surgical patients; and Use of antibiotic-impregnated central venous catheters to prevent catheter-related infections. CONCLUSIONS: An evidence-based approach can help identify practices that are likely to improve patient safety. Such practices target a diverse array of safety problems. Further research is needed to fill the substantial gaps in the evidentiary base, particularly with regard to the generalizability of patient safety practices heretofore tested only in limited settings and to promising practices drawn from industries outside of health care.

Accreditation↗
PubMedDate not supplied

Reducing vancomycin use utilizing a computer guideline: results of a randomized controlled trial.

BACKGROUND: Vancomycin-resistant enterococci represent an increasingly important cause of nosocomial infections. Minimizing vancomycin use represents a key strategy in preventing the spread of these infections. OBJECTIVE: To determine whether a structured ordering intervention using computerized physician order entry that requires use of a guideline could reduce intravenous vancomycin use. DESIGN: Randomized controlled trial assessing frequency and duration of vancomycin therapy by physicians. PARTICIPANTS AND SETTING: Three hundred ninety-six physicians and 1,798 patients in a tertiary-care teaching hospital. INTERVENTION: Computer screen displaying, at the time of physician order entry, an adaptation of the Centers for Disease Control and Prevention guidelines for appropriate vancomycin use. MAIN OUTCOME MEASURES: The frequency of initiation and renewal of vancomycin therapy as well the duration of therapy prescribed on a per prescriber basis. RESULTS: Compared with the control group, intervention physicians wrote 32 percent fewer orders (11.3 versus 16.7 orders per physician; P = 0.04) and had 28 percent fewer patients for whom they either initiated or renewed an order for vancomycin (7.4 versus 10.3 orders per physician; P = 0.02). In addition, the duration of vancomycin therapy attributable to physicians in the intervention group was 36 percent lower than the duration of therapy prescribed by control physicians (26.5 versus 41.2 days; P = 0.05). Analysis of pharmacy data confirmed a decrease in the overall hospital use of intravenous vancomycin during the study period. CONCLUSION: Implementation of a computerized guideline using physician order entry decreased vancomycin use. Computerized guidelines represent a promising tool for changing prescribing practices.

Drug Prescriptions↗
PubMedDate not supplied

Taking advantage of the explosion of systematic reviews: an efficient MEDLINE search strategy.

CONTEXT: Systematic reviews of the literature are an important resource for clinicians. Unfortunately, the few published strategies for identifying these articles involve MEDLINE interfaces not widely available outside of academic medicine. In addition, the performance of these strategies is unknown. OBJECTIVE: To develop and evaluate a search strategy for identifying systematic reviews by using a publicly available MEDLINE interface (PubMed). DESIGN: Diagnostic test assessment. DEFINITION OF SENSITIVITY: The proportion of recognized systematic reviews (indexed in the Cochrane Library's Database of Abstracts of Reviews of Effectiveness [DARE] or in ACP Journal Club) that are identified by the search strategy. DEFINITION OF POSITIVE PREDICTIVE VALUE: The proportion of articles identified in one of three sample searches (screening for colorectal cancer, thrombolytic therapy for venous thromboembolism, and treatment of dementia) that meet a minimum definition of systematic review. RESULTS: Our PubMed search strategy identified 93 of 100 DARE-indexed systematic reviews, a sensitivity of 93% (95% CI, 86% to 97%). For the sample of systematic reviews drawn from ACP Journal Club (n = 103), the PubMed strategy achieved a sensitivity of 97% (CI, 91% to 99%). When the three sample search strings were used, approximately 50% of retrieved articles met our minimum definition of systematic review. In contrast, the similar precision of a PubMed search restricted to review-type articles (as indexed by MEDLINE) was less than 10%. CONCLUSIONS: This search strategy identified most systematic reviews without over-whelming users with numerous false-positive results. A "single-click" filter based on this strategy is now available as part of the Clinical Queries feature of PubMed.

Evidence-Based Medicine↗