Laura A. Petersen

Incidence of adverse drug events and potential adverse drug events. Implications for prevention. ADE Prevention Study Group.

OBJECTIVES To assess incidence and preventability of adverse drug events (ADEs) and potential ADEs. To analyze preventable events to develop prevention strategies. DESIGN Prospective cohort study. PARTICIPANTS All 4031 adult admissions to a stratified random sample of 11 medical and surgical units in two tertiary care hospitals over a 6-month period. Units included two medical and three surgical intensive care units and four medical and two surgical general care units. MAIN OUTCOME MEASURES Adverse drug events and potential ADEs. METHODS Incidents were detected by stimulated self-report by nurses and pharmacists and by daily review of all charts by nurse investigators. Incidents were subsequently classified by two independent reviewers as to whether they represented ADEs or potential ADEs and as to severity and preventability. RESULTS Over 6 months, 247 ADEs and 194 potential ADEs were identified. Extrapolated event rates were 6.5 ADEs and 5.5 potential ADEs per 100 nonobstetrical admissions, for mean numbers per hospital per year of approximately 1900 ADEs and 1600 potential ADEs. Of all ADEs, 1% were fatal (none preventable), 12% life-threatening, 30% serious, and 57% significant. Twenty-eight percent were judged preventable. Of the life-threatening and serious ADEs, 42% were preventable, compared with 18% of significant ADEs. Errors resulting in preventable ADEs occurred most often at the stages of ordering (56%) and administration (34%); transcription (6%) and dispensing errors (4%) were less common. Errors were much more likely to be intercepted if the error occurred earlier in the process: 48% at the ordering stage vs 0% at the administration stage. CONCLUSION Adverse drug events were common and often preventable; serious ADEs were more likely to be preventable. Most resulted from errors at the ordering stage, but many also occurred at the administration stage. Prevention strategies should target both stages of the drug delivery process.

Racial and ethnic disparities in the use of health services: Bias, preferences, or poor communication?

African Americans and Latinos use services that require a doctor’s order at lower rates than do whites. Racial bias and patient preferences contribute to disparities, but their effects appear small. Communication during the medical interaction plays a central role in decision making about subsequent interventions and health behaviors. Research has shown that doctors have poorer communication with minority patients than with others, but problems in doctor-patient communication have received little attention as a potential cause, a remediable one, of health disparities. We evaluate the evidence that poor communication is a cause of disparities and propose some remedies drawn from the communication sciences.

Measuring Errors and Adverse Events in Health Care

In this paper, we identify 8 methods used to measure errors and adverse events in health care and discuss their strengths and weaknesses. We focus on the reliability and validity of each, as well as the ability to detect latent errors (or system errors) versus active errors and adverse events. We propose a general framework to help health care providers, researchers, and administrators choose the most appropriate methods to meet their patient safety measurement goals.

Using a computerized sign-out program to improve continuity of inpatient care and prevent adverse events.

BACKGROUND Many medical injuries are preventable, but there are few reported successful strategies to prevent such injuries. Previous work identified coverage by house staff not primarily responsible for the patient (cross-coverage) as a significant correlate of risk for preventable adverse events. A four-month intervention--computerized sign-outs--was introduced in 1993 in an urban teaching hospital to improve continuity of care during cross-coverage and thereby reduce risk for preventable adverse events. MEASUREMENTS A previously tested confidential self-report system was used to identify adverse events, which were defined as unexpected complications of medical therapy that resulted in increased length of stay or disability at discharge. A panel of three board-certified internists confirmed events and evaluated preventability based on case summaries. RESULTS After the intervention, the rate of preventable adverse events among the 3,747 patients admitted to the medical service decreased from 1.7% to 1.2% (p < 0.10). Both univariate and multivariate analysis revealed no association between cross coverage and preventable adverse events after the intervention. In the baseline period, the odds ratio (OR) for a patient suffering a preventable adverse event during cross coverage was 5.2 (95% confidence interval [CI], 1.5-18.2; p = 0.01), but was no longer significant after the intervention (OR, 1.5; 95% CI, 0.2-9.0). CONCLUSION House staff are willing participants in efforts to measure and improve the quality of health care systems. The intervention may have reduced the risk for medical injury associated with discontinuity of inpatients care. Four years after the end of the study, the computerized sign-out program remained an integral part of the computing support system for house staff and was widely used.

Positive Predictive Value of the Diagnosis of Acute Myocardial Infarction in an Administrative Database

OBJECTIVE: To determine the positive predictive value of ICD-9-CM coding of acute myocardial infarction and cardiac procedures.METHODS: Using chart-abstracted data as the standard, we examined administrative data from the Veterans Health Administration for a national random sample of 5,151 discharges.MAIN RESULTS: The positive predictive value of acute myocardial infarction coding in the primary position was 96.9%. The sensitivity and specificity of coding were, respectively, 96% and 99% for catheterization, 95.7% and 100% for coronary artery bypass graft surgery, and 90.3% and 99.7% for percutaneous transluminal coronary angioplasty.CONCLUSIONS: The positive predictive value of acute myocardial infarction and related procedure coding is comparable to or better than previously reported observations of administrative databases.

Timely Follow-up of Abnormal Diagnostic Imaging Test Results in an Outpatient Setting Are Electronic Medical Records Achieving Their Potential?

BACKGROUND Given the fragmentation of outpatient care, timely follow-up of abnormal diagnostic imaging results remains a challenge. We hypothesized that an electronic medical record (EMR) that facilitates the transmission and availability of critical imaging results through either automated notification (alerting) or direct access to the primary report would eliminate this problem. METHODS We studied critical imaging alert notifications in the outpatient setting of a tertiary care Department of Veterans Affairs facility from November 2007 to June 2008. Tracking software determined whether the alert was acknowledged (ie, health care practitioner/provider [HCP] opened the message for viewing) within 2 weeks of transmission; acknowledged alerts were considered read. We reviewed medical records and contacted HCPs to determine timely follow-up actions (eg, ordering a follow-up test or consultation) within 4 weeks of transmission. Multivariable logistic regression models accounting for clustering effect by HCPs analyzed predictors for 2 outcomes: lack of acknowledgment and lack of timely follow-up. RESULTS Of 123 638 studies (including radiographs, computed tomographic scans, ultrasonograms, magnetic resonance images, and mammograms), 1196 images (0.97%) generated alerts; 217 (18.1%) of these were unacknowledged. Alerts had a higher risk of being unacknowledged when the ordering HCPs were trainees (odds ratio [OR], 5.58; 95% confidence interval [CI], 2.86-10.89) and when dual-alert (>1 HCP alerted) as opposed to single-alert communication was used (OR, 2.02; 95% CI, 1.22-3.36). Timely follow-up was lacking in 92 (7.7% of all alerts) and was similar for acknowledged and unacknowledged alerts (7.3% vs 9.7%; P = .22). Risk for lack of timely follow-up was higher with dual-alert communication (OR, 1.99; 95% CI, 1.06-3.48) but lower when additional verbal communication was used by the radiologist (OR, 0.12; 95% CI, 0.04-0.38). Nearly all abnormal results lacking timely follow-up at 4 weeks were eventually found to have measurable clinical impact in terms of further diagnostic testing or treatment. CONCLUSIONS Critical imaging results may not receive timely follow-up actions even when HCPs receive and read results in an advanced, integrated electronic medical record system. A multidisciplinary approach is needed to improve patient safety in this area.

NONURGENT EMERGENCY DEPARTMENT VISITS : THE EFFECT OF HAVING A REGULAR DOCTOR

OBJECTIVES The authors assess the association between having a regular doctor and presentation for nonurgent versus urgent emergency department visits while controlling for potential confounders such as sociodemographics, health status, and comorbidity. METHODS A cross-sectional study was conducted in emergency departments of five urban teaching hospitals in the northeast. Adult patients presenting with chest pain, abdominal pain, or asthma (n = 1696; 88% of eligible) were studied. Patients completed a survey on presentation, reporting sociodemographics, health status, comorbid diseases, and relationship with a regular doctor. Urgency on presentation was assessed by chart review using explicit criteria. RESULTS Of the 1,696 study participants, 852 (50%) presented with nonurgent complaints. In logistic regression analyses, absence of a relationship with a regular physician was an independent correlate of presentation for a nonurgent emergency department visit (odds ratio 1.6; 95% confidence interval 1.2, 2.2) when controlling for age, gender, marital status, health status, and comorbid diseases. Race, lack of insurance, and education were not associated with nonurgent use. CONCLUSIONS Absence of a relationship with a regular doctor was correlated with use of the emergency department for selected nonurgent conditions when controlling for important potential confounders. Our study suggests that maintaining a relationship with a regular physician may reduce nonurgent use of the emergency department regardless of insurance status or health status.

Outcome of Myocardial Infarction in Veterans Health Administration Patients as Compared with Medicare Patients

BACKGROUND Some have the opinion that patients cared for in Veterans Health Administration (VHA) hospitals receive care of poorer quality than those cared for in non-VHA institutions. To assess the quality of care in VHA hospitals, we compared the outcome of acute myocardial infarction among patients in VHA and non-VHA institutions while controlling for potential confounders, including coexisting conditions and severity of illness. METHODS We studied 2486 veterans discharged from 81 VHA hospitals and 29,249 Medicare patients discharged from 1530 non-VHA hospitals, restricting our samples to men at least 65 years of age who were discharged with confirmed acute myocardial infarction. We compared coexisting conditions, severity of illness, and 30-day and 1-year mortality in the two samples. RESULTS VHA patients were significantly more likely than Medicare patients to have a recorded history of hypertension (64.3 percent vs. 57.3 percent), chronic obstructive pulmonary disease or asthma (30.9 percent vs. 23.5 percent), diabetes (34.8 percent vs. 29.0 percent), stroke (20.4 percent vs. 14.2 percent), or dementia (7.2 percent vs. 4.8 percent) (P<0.001 for all comparisons). According to both multivariate logistic regression and an analysis using 2265 matched pairs of VHA and Medicare patients, there were no significant differences in 30-day or 1-year mortality. The matched-pairs analysis found that the difference in mortality at 30 days (the mortality rate among Medicare patients minus the mortality rate among VHA patients), averaged over the 5-year age groups, was -0.8 percent (95 percent confidence interval, -2.8 percent to 1.3 percent), and the difference in mortality at 1 year was -1.3 percent (95 percent confidence interval, -3.9 percent to 1.3 percent). CONCLUSIONS VHA patients had more coexisting conditions than Medicare patients. Nevertheless, we found no significant difference in mortality between VHA and Medicare patients, a result that suggests a similar quality of care for acute myocardial infarction.

Impact of race on cardiac care and outcomes in veterans with acute myocardial infarction.

Objectives. The goal of this study was to assess racial differences in process of care and outcome for acute myocardial infarction in the VA health care system. Design. Retrospective cohort study using clinical data. Setting. Eighty-one acute care VA hospitals. Patients. Four thousand seven hundred sixty veterans discharged with a confirmed diagnosis of acute myocardial infarction. The analysis was restricted to 606 black and 4005 white patients. Main Outcome Measures. Comparison of use of guideline-based medications, invasive cardiac procedures, and all-cause mortality at 30 days, 1 year, and 3 years. Results. Black patients were equally likely to receive &bgr;-blockers, more likely than white patients to receive aspirin (86.8% vs. 82.0%;P <0.05), and marginally more likely to receive angiotensin converting enzyme inhibitors (55.7% vs. 49.6%;P = 0.07) at the time of discharge. In contrast, black patients were less likely than white patients to receive thrombolytic therapy at the time of arrival (32.4% vs. 48.2%;P <0.01). There was no significant difference in refusal of angiography or percutaneous transluminal coronary angioplasty between black patients and white patients, or in crude rates of either of these procedures. There was also no difference overall in the percentage of patients who refused coronary artery bypass graft surgery. However, black patients were less likely than white patients to undergo bypass surgery (6.9% vs. 12.5% by 90 days;P <0.001). Black patients remained less likely to undergo bypass surgery even when high-risk specific coronary anatomy subgroups were examined. There was no difference in mortality in the two groups. Conclusions. In this integrated health care system, no significant racial disparities in use of noninterventional therapies, diagnostic coronary angiography, or short- or long-term mortality was found. Disparities in use of thrombolytic therapy and coronary artery bypass surgery existed, however, even after accounting for differences in clinical indications for treatment and patient refusals. Further work should assess the role of the medical interaction and physician behavior in racial disparities in use of health care.

Understanding diagnostic errors in medicine: a lesson from aviation

The impact of diagnostic errors on patient safety in medicine is increasingly being recognized. Despite the current progress in patient safety research, the understanding of such errors and how to prevent them is inadequate. Preliminary research suggests that diagnostic errors have both cognitive and systems origins. Situational awareness is a model that is primarily used in aviation human factors research that can encompass both the cognitive and the systems roots of such errors. This conceptual model offers a unique perspective in the study of diagnostic errors. The applicability of this model is illustrated by the analysis of a patient whose diagnosis of spinal cord compression was substantially delayed. We suggest how the application of this framework could lead to potential areas of intervention and outline some areas of future research. It is possible that the use of such a model in medicine could help reduce errors in diagnosis and lead to significant improvements in patient care. Further research is needed, including the measurement of situational awareness and correlation with health outcomes.