Mary F. Wisniewski

Diagnostic Error in Medicine: Analysis of 583 Physician-Reported Errors

BACKGROUND Missed or delayed diagnoses are a common but understudied area in patient safety research. To better understand the types, causes, and prevention of such errors, we surveyed clinicians to solicit perceived cases of missed and delayed diagnoses. METHODS A 6-item written survey was administered at 20 grand rounds presentations across the United States and by mail at 2 collaborating institutions. Respondents were asked to report 3 cases of diagnostic errors and to describe their perceived causes, seriousness, and frequency. RESULTS A total of 669 cases were reported by 310 clinicians from 22 institutions. After cases without diagnostic errors or lacking sufficient details were excluded, 583 remained. Of these, 162 errors (28%) were rated as major, 241 (41%) as moderate, and 180 (31%) as minor or insignificant. The most common missed or delayed diagnoses were pulmonary embolism (26 cases [4.5% of total]), drug reactions or overdose (26 cases [4.5%]), lung cancer (23 cases [3.9%]), colorectal cancer (19 cases [3.3%]), acute coronary syndrome (18 cases [3.1%]), breast cancer (18 cases [3.1%]), and stroke (15 cases [2.6%]). Errors occurred most frequently in the testing phase (failure to order, report, and follow-up laboratory results) (44%), followed by clinician assessment errors (failure to consider and overweighing competing diagnosis) (32%), history taking (10%), physical examination (10%), and referral or consultation errors and delays (3%). CONCLUSIONS Physicians readily recalled multiple cases of diagnostic errors and were willing to share their experiences. Using a new taxonomy tool and aggregating cases by diagnosis and error type revealed patterns of diagnostic failures that suggested areas for improvement. Systematic solicitation and analysis of such errors can identify potential preventive strategies.

Computer Algorithms To Detect Bloodstream Infections

Automated bloodstream infection surveillance using electronic data is an accurate alternative to surveillance using manually collected data.

Antibiotic Combinations with Redundant Antimicrobial Spectra: Clinical Epidemiology and Pilot Intervention of Computer-Assisted Surveillance

Redundant antibiotic combinations are a potentially remediable source of antibiotic overuse. At a public teaching hospital, we determined the incidence, cost, and indications for such combinations and measured the effects of a pharmacist-based intervention. Of 1189 inpatients receiving >or=2 antibiotics, computer-assisted screening identified 192 patients (16.1%) receiving potentially redundant combinations. Chart reviews showed that 137 episodes (71%) were inappropriate. Physician overprescribing errors were found in 77 episodes (56%); most involved redundant coverage for gram-positive or anaerobic organisms. In 76 episodes (55%), lapses in the medication ordering and distribution system led to the persistence in the pharmacy records of regimens no longer active according to the patient charts. The incidence of redundant antibiotic combinations was significantly higher in the intensive care unit and surgery services, compared with medical services. Interventions to discontinue redundant agents were successful in 134 (98%) of the 137 episodes. Potential drug cost savings and reduction in redundant antibiotic combination days were 10,800 dollars and 584 days, respectively; pharmacist time for patient review and intervention cost 2880 dollars. Use of redundant antibiotic combinations was common, and a pharmacist-based intervention was feasible, with a potential annualized cost savings of 48,000 dollars.

Unnecessary use of central venous catheters: The need to look outside the intensive care unit

We developed criteria for justifiable CVC use and evaluated CVC use in a public hospital. Unjustified CVC-days were more common for non-ICU patients compared with ICU patients. Also, insertion-site dressings were less likely to be intact on non-ICU patients. Interventions to reduce CVC-associated bloodstream infections should include non-ICU patients.

Preventing central venous catheter-associated primary bloodstream infections: characteristics of practices among hospitals participating in the Evaluation of Processes and Indicators in Infection Control (EPIC) study.

OBJECTIVES To describe the conceptual framework and methodology of the Evaluation of Processes and Indicators in Infection Control (EPIC) study and present results of CVC insertion characteristics and organizational practices for preventing BSIs. The goal of the EPIC study was to evaluate relationships among processes of care, organizational characteristics, and the outcome of BSI. DESIGN This was a multicenter prospective observational study of variation in hospital practices related to preventing CVC-associated BSIs. Process of care information (eg, barrier use during insertions and experience of the inserting practitioner) was collected for a random sample of approximately 5 CVC insertions per month per hospital during November 1998 to December 1999. Organization demographic and practice information (eg, surveillance activities and staff and ICU nurse staffing levels) was also collected. SETTING Medical, surgical, or medical-surgical ICUs from 55 hospitals (41 U.S. and 14 international sites). PARTICIPANTS Process information was obtained for 3,320 CVC insertions with an average of 58.2 (+/- 16.1) insertions per hospital. Fifty-four hospitals provided policy and practice information. RESULTS Staff spent an average of 13 hours per week in study ICU surveillance. Most patients received nontunneled, multiple lumen CVCs, of which fewer than 25% were coated with antimicrobial material. Regarding barriers, most clinicians wore masks (81.5%) and gowns (76.8%); 58.1% used large drapes. Few hospitals (18.1%) used an intravenous team to manage ICU CVCs. CONCLUSIONS Substantial variation exists in CVC insertion practice and BSI prevention activities. Understanding which practices have the greatest impact on BSI rates can help hospitals better target improvement interventions.

Effect of education on hand hygiene beliefs and practices : A 5-year program

To evaluate infection control and hand hygiene understanding at 3 public hospitals, we surveyed 4,345 healthcare workers (HCWs) 3 times during a 5-year infection control intervention. The preference for the use of alcohol hand rub for hand hygiene increased dramatically; in nurses, it increased from 14% to 34%; in physicians, 4.3% to 51%; and in allied HCWs, 12% to 44%. Study year, infection control interactive education-session attendance, infection control knowledge, and being a physician or allied HCW independently predicted a preference for alcohol hand rub.

The Effect of Renal Dysfunction on Antimicrobial Use Measurements

The defined daily dose, a popular measurement of antimicrobial use, may underestimate the use of antimicrobials that are dose-adjusted in patients with renal insufficiency. To evaluate the effect of renal dysfunction on these measures, we performed a retrospective cohort study that involved patients receiving ceftriaxone, levofloxacin, or vancomycin, with use of defined daily doses and 2 methods based on therapy duration--stop-start days (i.e., entire therapy duration) and transaction days (i.e., unique therapeutic days). The vancomycin use rate for patients with renal insufficiency was 36% lower than that of patients with normal renal function for defined daily doses, and it was 23% lower for transaction days; for levofloxacin, there was a 27% rate reduction for the defined daily dose. No significant reduction was noted when the stop-start day method was used. Compared with the defined daily dose method, measures of therapy duration are less affected by renal function and may improve comparisons between populations.

Electronic Interpretation of Chest Radiograph Reports to Detect Central Venous Catheters

OBJECTIVE To evaluate whether a natural language processing system, SymText, was comparable to human interpretation of chest radiograph reports for identifying the mention of a central venous catheter (CVC), and whether use of SymText could detect patients who had a CVC. DESIGN To identify patients who had a CVC, we performed two surveys of hospitalized patients. Then, we obtained available reports from 104 patients who had a CVC during one of two cross-sectional surveys (ie, case-patients) and 104 randomly selected patients who did not have a CVC (ie, control-patients). SETTING A 600-bed public teaching hospital. RESULTS Chest radiograph reports were available from 124 of the 208 participants. Compared with human interpretation, SymText had a sensitivity of 95.8% and a specificity of 98.7%. The use of SymText to identify case- and control-patients resulted in a sensitivity of 43% and a specificity of 98%. Successful application of SymText varied significantly by venous insertion site (eg, a sensitivity of 78% for subclavian and a sensitivity of 3.7% for femoral). Twenty-six percent of the case-patients had a femoral CVC. CONCLUSIONS Compared with human interpretation, SymText performed well in interpreting whether a report mentioned a CVC. In patient populations with less frequent CVC placement in femoral veins, the sensitivity for CVC detection likely would be higher. Applying a natural language processing system to chest radiograph reports may be a useful adjunct to other data sources to automate detection of patients who had a CVC.

Antimicrobial consumption data from pharmacy and nursing records: How good are they?

OBJECTIVE To determine whether randomly selected intravenous (IV) antimicrobial doses dispensed from an inpatient pharmacy were administered. DESIGN This was a prospective, cross-sectional study in which dose administration was confirmed by direct observation and by assessment of the medication administration record (MAR). A retrospective analysis of the return rate of unused IV antimicrobial doses was performed subsequently. SETTING Medical and surgical intensive care units (ICUs) and non-ICUs of a 550-bed urban public teaching hospital. PARTICIPANTS Hospitalized patients with an order in the pharmacy database for an IV antimicrobial during 9 non-consecutive weekdays in June 1999. RESULTS Of 397 doses, 221 (55.7%) assessed by bedside observation and 238 (59.9%) assessed by MAR review were classified as administered; 139 doses (35.0%) were dispensed but changes in the drug order or the patients status prevented their administration. In the subsequent assessment, of 745 IV antimicrobial doses dispensed during 24 hours, 322 (43.2%) were returned to the pharmacy unused; 423 (56.8%) of the doses-consistent with our prior observations-were presumably administered. CONCLUSIONS Because computerized pharmacy data may overestimate actual antimicrobial consumption, such data should be validated when used in studies of hospital antimicrobial use. Dispense-return analysis offers a simple validation method.

SERTRALINE TABLET SPLITTING PROGRAM

Hospital Pharmacy welcomes contributions to this column. Articles originally published in pharmacy department newsletters are reprinted here. Material is selected because of its educational value to pharmacists or because it demonstrates the type of information of interest to newsletter readers. If you wish to have your newsletter material considered for publication in this column, mail a copy—along with a computer disk containing the document—to Neil M. Davis, Editor-in-Chief, Hospital Pharmacy, 1143 Wright Drive, Huntingdon Valley, PA 19006-2721.