Presentation on theme: "Medical Errors: Causes and Prevention"— Presentation transcript:
1 Medical Errors: Causes and Prevention Roger L. Bertholf, Ph.D.Associate Professor of PathologyUniversity of Florida Health Science Center/Jacksonville
2 IOM: To Err Is Human: Building a Safer Health System (2000) FrequencyCostOutcomesTypesCausesRecommendations
3 Adverse Event vs. ErrorAn adverse event is an injury caused by medical management rather than the underlying condition of the patient. An adverse event attributable to error is a "preventable adverse event." Negligent adverse events represent a subset of preventable adverse events that satisfy legal criteria used in determining negligence (i.e., whether the care provided failed to meet the standard of care reasonably expected of an average physician qualified to take care of the patient in question).*An error is defined as the failure of a planned action to be completed as intended (i.e., error of execution) or the use of a wrong plan to achieve an aim (i.e., error of planning).*About half of preventable AEs are considered negligent
4 Examples of Medical Errors Diagnostic error (inappropriate therapy)Equipment failureInfection (nosocomial, post-operative)Transfusion-related injuryMisinterpretation of medical ordersSystem failures that compromise diagnostic or treatment processes.
5 Frequency of Medical Errors StudyAEsErrorsFatalEst. DeathsNY (1984)2.9%58%13.6%98,000CO/UT (1992)3.7%53%6.6%44,000††MVA = 43,000; Breast CA = 42,000; AIDS = 16,000. 8th most frequent cause overall.
6 How reliable is this estimate? Includes only AEs producing a specified level or harmTwo reviewers had to agree on whether an AE was preventable or negligentIncluded only AEs documented in the patient record**Some studies, using other sources of information about adverse events, produced higher estimates.
7 Cost Adverse events: $37.6 – 50 billion* Preventable adverse events: $17 – 29 billionHalf of cost is for health careRepresent 4% (AE)† and 2% (errors) of all health care costs*lost income, lost household production, disability, health care costs†Exceeds total cost of treating HIV and AIDS
8 Causes* Medication error 19%† Wound infection 14% Technical complications13%*Leape et al. (1991) The nature of adverse events in hospitalized patients(1,133 AEs studied in 30,195 admissions)†Overall frequency (inpatients) is 3 per 1,000 medication orders; 2 per 1,000 considered “significant” errors
9 AHA List of Medication Errors Incomplete patient informationUnavailable drug information (warnings)Miscommunication of medication orderConfusion between drugs with similar namesLack of appropriate drug labelingEnvironmental conditions that distract health care providers
10 Most Common Medication Errors Failure to adjust dosage in response to a change in hepatic/renal function13.9%History of allergy to the same or related medication12.1%Wrong drug name, dosage form, or abbreviation on order11.4%Incorrect dosage calculation11.1%Atypical or unusual critical dosage consideration10.8%
11 A Comparison of RisksRisk (per flight) of dying in a commercial airline accident1 in 8 million*Risk (per hospital admission) of dying from a medical error>1 in 1,000*1 in 2 million from
12 Six Sigma Quality Control Quality Management program designed by Mikel Harry and Richard Schroeder in 2000Strives to make QM a quantitative scienceSets performance standards and goals for a production process
14 Six Sigma Process Performance Target- Tolerance+ ToleranceProbability.67.95-6-5-4-3-2-1123456SD ()
15 Six Sigma Performance Goal is to achieve < 1 DPM Not all processes can achieve the 6 level of performance“Deming’s Principle” is that fewer defects leads to increased productivity, efficiency, and lower cost
16 Healthcare’s Six Sigma Performance Process% ErrorsSigmaPreventable adverse events3.02.5Lab order accuracy1.83.6Reporting errors0.0484.8False negative PAP2.43.45Unacceptable specimen0.34.25Duplicate test orders1.523.65
18 Sidney Dekker“What is striking about many accidents is that people were doing exactly the sorts of things they would usually be doing—the things that usually lead to success and safety. . .Accidents are seldom preceded by bizarre behavior.”From The Field Guide to Human Error Investigations (2002)
19 A Primer on Accident Investigation Human error as a causeHuman error as a symptom
20 Human Error Bad Apple Theory Reaction to failure Complex systems are inherently safeHuman intervention subverts the inherent safety of complex systemsReaction to failureBad outcome = bad decisionRetrospective, proximal, counterfactual, and judgmental
21 The Bad Apple Theory The illusion of success Failure is an aberration Bad procedures often produce good resultsSuccess breeds confidenceFailure is an aberration“The system must be safe”The economical answerIt is easier to change human behavior than it is to change systems
25 ProximityIt is intuitive to focus on the location where the failure occurred“Sharp end” vs. “Blunt end”The “sharp end” is the point at which the failure occursThe “blunt end” is the set of systems and organizational structure that supports the activities at the “sharp end”
26 Retrospective Analysis Sharp EndTimeInstitutionSystemsProceduresOrganizationBlunt End
28 What Might Have Been. . .In retrospect, it is always easy to see where different actions would have averted a bad outcomeIn retrospect, the outcome of any potential action is already known“Counterfactuals” pose alternate scenarios, which are rarely useful in determining the true cause
30 The Omniscient Perspective As an investigator, you always know more than the participants didIt is very difficult, if not impossible to judge fairly the reactions of those who had less information than youInvestigators define “failure” based on outcome
31 Lessons for Investigators There is no “primary” causeEvery action affects anotherThere is no single causeErrors in complex systems are nearly always multi-focalA definition of “human error” is elusiveDefinition of “error”Humans operate within complex systems
32 Failure Mode and Effects Analysis Everything will eventually failHumans frequently make errorsThe cause of a failure is often beyond the control of an operator
33 10 Steps for FMEA Review the process Brainstorm potential failure modesList potential effects of each failure modeAssign a severity ratingAssign an occurrence ratingAssign a detection ratingCalculate the risk priority number for each effectPrioritize these failure modes based on the RPN and severityTake action to reduce or eliminate the high-risk failure modesRecalculate the RPN
34 Ranking the Failure Modes Calculate the RPNRate Severity, Occurrence, and Detection on a scale of 1 – 10RPN = S x O x D (maximum 1000)Prioritize Failure modesNot strictly based on RPNSeverity of 9 or 10 should get priorityGoal is to reduce RPN
36 Case Exercise #1A 91-year-old female was transferred to a hospital-based skilled nursing unit from the acute care hospital for continued wound care and intravenous (IV) antibiotics for methicillin-resistant Staphylococcus aureus (MRSA) osteomyelitis of the heel. She was on IV vancomycin and began to have frequent, large stools.
37 Case Exercise #1The attending physician ordered a test for Clostridium difficile on Friday, and was then off for the weekend. That night, the test result came back positive. The lab called infection control, who in turn notified the float nurse caring for the patient. The nurse did not notify the physician on call or the regular nursing staff. Isolation signs were posted on the patient's door and chart, and the result was noted in the patient's nursing record. Each nurse who subsequently cared for this patient assumed that the physician had been notified, in large part because the patient was receiving vancomycin. However, it was IV vancomycin (for the MRSA osteomyelitis), not oral vancomycin, which is required to treat C. difficile.
38 Case Exercise #1On Monday, the physician who originally ordered the C. difficile test returned to assess the patient and found the isolation signs on her door. He asked why he was never notified and why the patient was not being treated. The nurse on duty at that time told him that the patient was on IV vancomycin. The float nurse, who had received the original notification from infection control, stated that she had assumed the physician would check the results of the test he had ordered. Due to the lack of follow-up, the patient went three days without treatment for C. difficile, and continued to have more than 10 loose stools daily. Given her advanced age, this degree of gastrointestinal loss undoubtedly played a role in her decline in functional status and extended hospital stay.
39 Case Exercise #1What are the systems/processes involved in this incident?What were the failure points?
40 Analysis MD failed to check the result of an ordered test Float RN wrongly assumed that MD had been notified of the resultRN incorrectly assumed that IV vancomycin was adequate therapy
41 Failure Points Laboratory system for reporting critical results Is a positive C. difficile culture considered a panic result?To whom are panic values reported?RN/MD communicationDoes the institution foster an environment where RNs can comfortably question MD orders?
42 Lisa Belkin“. . . it is virtually impossible for one mistake to kill a patient in the highly mechanized and backstopped world of a modern hospital. A cascade of unthinkable things must happen, meaning catastrophic errors are rarely a failure of a single person, and almost always a failure of a system.”From How Can We Save the Next Victim? (NY Times Magazine, June 15, 1997)
43 Case Exercise #2An 81-year-old female maintained on warfarin for a history of chronic atrial fibrillation and mitral valve replacement developed asymptomatic runs of ventricular tachycardia while hospitalized. The unit nurse contacted the physician, who was engaged in a sterile procedure in the cardiac catheterization laboratory (cath lab) and gave a verbal order, which was relayed to the unit nurse via the procedure area nurse. Someone in the verbal order process said "40 of K." The unit nurse (whose past clinical experience was in neonatal intensive care) wrote the order as "Give 40 mg Vit K IV now."
44 Case Exercise #2The hospital pharmacist contacted the physician concerning the high dose and the route and discovered that the intended order was "40 mEq of KCl po." The pharmacist wrote the clarification order. However, the unit nurse had already obtained vitamin K on override from the Pyxis MedStation® (an automated medication dispensing system) and administered the dose intravenoustly (IV). The nurse attempted to contact the physician but was told he was busy with procedures. A routine order to increase warfarin from 2.5 mg to 5 mg (based on an earlier INR) was written later in the day and interpreted by the evening shift nurse as the physician’s response to the medication event. The physician was not actually informed that the vitamin K had been administered until the next day. Heparin was initiated and warfarin was re-titrated to a therapeutic level. The patient’s INR was sub-herapeutic for 3 days, but no untoward clinical consequences occurred.
45 Case Exercise #2What are the systems/processes involved in this incident?What were the failure points?
46 Analysis Verbal orders Failure to question unusual orders Third party “messengers”Use of abbreviationsFailure to question unusual ordersLack of control over medication availability
47 Failure Points Hospital policy for medication orders “Read Back” requirementAbility to circumvent pharmacist review
48 J.C.R. Licklider ( )“It seems likely that the contributions of human operators and [computers] will blend together so completely in many operations that it will be difficult to separate them neatly in analysis.”From Man-Computer Symbiosis (1960)
50 Phase I: A failed calibration Recalibration of the acetaminophen assay was prompted by a QC failureRecalibration was followed by acceptable QC results
51 Phase II: QC failuresSubsequent QC measurements produced an error code indicating the result was above the linear limit of the methodQC failures went unnoticed, since the LIS did not display the error codeSeveral patient specimens were reported incorrectly, resulting in inappropriate treatment
52 Phase III: DiscoveryThe ED staff contacted the laboratory to question the high acetaminophen result on a patient who denied recent ingestion of the drugInvestigation revealed the QC failures, and the assay was successfully recalibrated
53 Phase IV: Investigation Principal Questions Why was an acceptable QC result obtained immediately after a failed calibration?Why didn’t the technologists notice subsequent QC failures?Should the clinicians have been more suspicious of unusually high results?
57 Unnoticed QC failures Interface through Digital Innovations box Error codes are rare in QC resultsSupervisory review does not occur regularly on weekends
58 Lack of clinical suspicion History is often unreliable in overdose casesAn antidote for acetaminophen existsSymptoms of acetaminophen toxicity may not appear until after the window of therapeutic opportunity has passed
59 ConclusionsAn unexpected error occurred in the calibration algorithm encoded in the instrument softwareThe failure of information to cross the instrument/LIS interface masked the erroneous control resultsSuspect results were not immediately apparent to clinicians
60 Lessons Complex technologies always have unexpected failure modes Interfaces between systems and operators are opportunities for distortion or loss of important informationThe fallacy of the “un-rocked boat”
61 Richard I. Cook“Recognizing hazard and successfully manipulating system operations to remain inside the tolerable performance boundaries requires intimate contact with failure.”From How Complex Systems Fail (2002)
62 How Complex Systems Fail Complex systems are intrinsically hazardous systemsComplex systems are heavily and successfully defended against failureCatastrophe requires multiple failures—single point failures are not enoughComplex systems contain changing mixtures of failures latent within them
63 How Complex Systems Fail Catastrophe is always just around the cornerPost-accident attribution to a “root cause” is fundamentally wrongHuman operators have dual roles: as producers and as defenders against failureHuman practitioners are the adaptable element of complex systems
64 How Complex Systems Fail Change introduces new forms of failureSafety is a characteristic of systems and not of their componentsFailure-free operations require experience with failure
65 IOM Recommendations Establish national focus Identify and learn from medical errors through mandatory reportingRaise standards and expectationsImplement safe practices
66 AHRQ Safety Recommendations for Patients Ask questions if you have doubts or concernsKeep and bring a list of ALL the medicines you takeGet the results of any test of procedureTalk to your doctor about which hospital is best for your health needsMake sure you understand what will happen if you need surgery