Impact of Clinician Training Background and Stroke Location on Bedside Diagnostic Test Accuracy in the Acute Vestibular Syndrome - A Meta-Analysis.

OBJECTIVE: Acute dizziness/vertigo is usually due to benign inner-ear causes but is occasionally due to dangerous neurologic ones, particularly stroke. Because symptoms and signs overlap, misdiagnosis is frequent and overuse of neuroimaging is common. We assessed the accuracy of bedside findings to differentiate peripheral vestibular from central neurologic causes. METHODS: We performed a systematic search (MEDLINE and Embase) to identify studies reporting on diagnostic accuracy of physical examination in adults with acute, prolonged dizziness/vertigo ("acute vestibular syndrome" [AVS]). Diagnostic test properties were calculated for findings. Results were stratified by examiner type and stroke location. RESULTS: We identified 6,089 citations and included 14 articles representing 10 study cohorts (n = 800). The Head Impulse, Nystagmus, Test of Skew (HINTS) eye movement battery had high sensitivity 95.3% (95% confidence interval [CI] = 92.5-98.1) and specificity 92.6% (95% CI = 88.6-96.5). Sensitivity was similar by examiner type (subspecialists 94.3% [95% CI = 88.2-100.0] vs non-subspecialists 95.0% [95% CI = 91.2-98.9], p = 0.55), but specificity was higher among subspecialists (97.6% [95% CI = 94.9-100.0] vs 89.1% [95% CI = 83.0-95.2], p = 0.007). HINTS sensitivity was lower in anterior cerebellar artery (AICA) than posterior inferior cerebellar artery (PICA) strokes (84.0% [95% CI = 65.3-93.6] vs 97.7% [95% CI = 93.3-99.2], p = 0.014) but was "rescued" by the addition of bedside hearing tests (HINTS+). Severe (grade 3) gait/truncal instability had high specificity 99.2% (95% CI = 97.8-100.0) but low sensitivity 35.8% (95% CI = 5.2-66.5). Early magnetic resonance imaging (MRI)-diffusion-weighted imaging (DWI; within 24-48 hours) was falsely negative in 15% of strokes (sensitivity 85.1% [95% CI = 79.2-91.0]). INTERPRETATION: In AVS, HINTS examination by appropriately trained clinicians can differentiate peripheral from central causes and has higher diagnostic accuracy for stroke than MRI-DWI in the first 24-48 hours. These techniques should be disseminated to all clinicians evaluating dizziness/vertigo. ANN NEUROL 2023;94:295-308.

Short-term stroke risk after emergency department treat-and-release headache visit.

OBJECTIVE: To evaluate whether patients discharged to home after an emergency department (ED) visit for headache face a heightened short-term risk of stroke. BACKGROUND: Stroke hospitalizations that occur soon after ED visits for headache complaints may reflect diagnostic error. METHODS: We conducted a retrospective cohort study using statewide administrative claims data for all ED visits and admissions at nonfederal hospitals in Florida 2005-2018 and New York 2005-2016. Using standard International Classification of Diseases (ICD) codes, we identified adult patients discharged to home from the ED (treat-and-release visit) with a benign headache diagnosis (cohort of interest) as well as those with a diagnosis of renal colic or back pain (negative controls). The primary study outcome was hospitalization within 30 days for stroke (ischemic or hemorrhagic) defined using validated ICD codes. We assess the relationship between index ED visit discharge diagnosis and stroke hospitalization adjusting for patient demographics and vascular comorbidities. RESULTS: We identified 1,502,831 patients with an ED treat-and-release headache visit; mean age was 41 (standard deviation: 17) years and 1,044,520 (70%) were female. A total of 2150 (0.14%) patients with headache were hospitalized for stroke within 30 days. In adjusted analysis, stroke risk was higher after headache compared to renal colic (hazard ratio [HR]: 2.69; 95% confidence interval [CI]: 2.29-3.16) or back pain (HR: 4.0; 95% CI: 3.74-4.3). In the subgroup of 26,714 (1.78%) patients with headache who received brain magnetic resonance imaging at index ED visit, stroke risk was only slightly elevated compared to renal colic (HR: 1.47; 95% CI: 1.22-1.78) or back pain (HR: 1.49; 95% CI: 1.24-1.80). CONCLUSION: Approximately 1 in 700 patients discharged to home from the ED with a headache diagnosis had a stroke in the following month. Stroke risk was three to four times higher after an ED visit for headache compared to renal colic or back pain.

Are Mental Health and Substance Use Disorders Risk Factors for Missed Acute Myocardial Infarction Diagnoses Among Chest Pain or Dyspnea Encounters in the Emergency Department?

STUDY OBJECTIVE: To assess if having a mental health and/or substance use disorder is associated with a missed acute myocardial infarction diagnosis in the emergency department (ED). METHODS: This was a retrospective cohort analysis (2009 to 2017) of adult ED encounters at Kaiser Permanente Southern California. We used the validated symptom-disease pair analysis of diagnostic error methodological approach to "look back" and "look forward" and identify missed acute myocardial infarctions within 30 days of a treat-and-release ED visit. We use adjusted logistic regression to report the odds of missed acute myocardial infarction among patients with a history of mental health and/or substance use disorders. RESULTS: The look-back analysis identified 44,473 acute myocardial infarction hospital encounters; 574 (1.3%) diagnoses were missed. The odds of missed diagnoses were higher in patients with mental health disorders (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.23 to 1.77) but not in those with substance abuse disorders (OR 1.22, 95% CI 0.91 to 1.62). The highest risk was observed in those with co-occurring disorders (OR 1.90, 95% CI 1.30 to 2.76). The look-forward analysis identified 325,088 chest pain/dyspnea ED encounters; 508 (0.2%) were missed acute myocardial infarctions. No significant associations of missed acute myocardial infarction were revealed in either group (mental health disorder: OR 0.92, 95% CI 0.71 to 1.18; substance use disorder: OR 1.22, 95% CI 0.80 to 1.85). CONCLUSION: The look-back analysis identified patients with mental illness at increased risk of missed acute myocardial infarction diagnosis, with the highest risk observed in those with a history of comorbid substance abuse. Having substance use disorders alone did not increase this risk in either cohort. The look-forward analysis revealed challenges in prospectively identifying high-risk patients to target for improvement.

Crossing Academic Boundaries for Diagnostic Safety: 10 Complex Challenges and Potential Solutions From Clinical Perspectives and High-Reliability Organizing Principles.

OBJECTIVE: We apply the high-reliability organization (HRO) paradigm to the diagnostic process, outlining challenges to enacting HRO principles in diagnosis and offering solutions for how diagnostic process stakeholders can overcome these barriers. BACKGROUND: Evidence shows that healthcare is starting to organize for higher reliability by employing various principles and practices of HRO. These hold promise for enhancing safer care, but there has been little consideration of the challenges that clinicians and healthcare systems face while enacting HRO principles in the diagnostic process. To effectively deploy the HRO perspective, these barriers must be seriously considered. METHOD: We review key principles of the HRO paradigm, the diagnostic errors and harms that potentially can be prevented by its enactment, the challenges that clinicians and healthcare systems face in executing various principles and practices, and possible solutions that clinicians and organizational leaders can take to overcome these challenges and barriers. RESULTS: Our analyses reveal multiple challenges including the inherent diagnostic uncertainty; the lack of diagnosis-focused performance feedback; the fact that diagnosis is often a solo, rather than team, activity; the tendency to simplify the diagnostic process; and professional and institutional status hierarchies. But these challenges are not insurmountable-there are strategies and solutions available to overcome them. CONCLUSION: The HRO lens offers some important ideas for how the safety of the diagnostic process can be improved. APPLICATION: The ideas proposed here can be enacted by both individual clinicians and healthcare leaders; both are necessary for making systematic progress in enhancing diagnostic performance.

Diagnostic Error of Neuro-ophthalmologic Conditions: State of the Science.

BACKGROUND: Diagnostic error is prevalent and costly, occurring in up to 15% of US medical encounters and affecting up to 5% of the US population. One-third of malpractice payments are related to diagnostic error. A complex and specialized diagnostic process makes neuro-ophthalmologic conditions particularly vulnerable to diagnostic error. EVIDENCE ACQUISITION: English-language literature on diagnostic errors in neuro-ophthalmology and neurology was identified through electronic search of PubMed and Google Scholar and hand search. RESULTS: Studies investigating diagnostic error of neuro-ophthalmologic conditions have revealed misdiagnosis rates as high as 60%-70% before evaluation by a neuro-ophthalmology specialist, resulting in unnecessary tests and treatments. Correct performance and interpretation of the physical examination, appropriate ordering and interpretation of neuroimaging tests, and generation of a differential diagnosis were identified as pitfalls in the diagnostic process. Most studies did not directly assess patient harms or financial costs of diagnostic error. CONCLUSIONS: As an emerging field, diagnostic error in neuro-ophthalmology offers rich opportunities for further research and improvement of quality of care.

A New Diagnostic Approach to the Adult Patient with Acute Dizziness.

BACKGROUND: Dizziness, a common chief complaint, has an extensive differential diagnosis that includes both benign and serious conditions. Emergency physicians must distinguish the majority of patients with self-limiting conditions from those with serious illnesses that require acute treatment. OBJECTIVE OF THE REVIEW: This article presents a new approach to diagnosis of the acutely dizzy patient that emphasizes different aspects of the history to guide a focused physical examination with the goal of differentiating benign peripheral vestibular conditions from dangerous posterior circulation strokes in the emergency department. DISCUSSION: Currently, misdiagnoses are frequent and diagnostic testing costs are high. This relates in part to use of an outdated, prevalent, diagnostic paradigm. The traditional approach, which relies on dizziness symptom quality or type (i.e., vertigo, presyncope, or disequilibrium) to guide inquiry, does not distinguish benign from dangerous causes, and is inconsistent with current best evidence. A new approach divides patients into three key categories using timing and triggers, guiding a differential diagnosis and targeted bedside examination protocol: 1) acute vestibular syndrome, where bedside physical examination differentiates vestibular neuritis from stroke; 2) spontaneous episodic vestibular syndrome, where associated symptoms help differentiate vestibular migraine from transient ischemic attack; and 3) triggered episodic vestibular syndrome, where the Dix-Hallpike and supine roll test help differentiate benign paroxysmal positional vertigo from posterior fossa structural lesions. CONCLUSIONS: The timing and triggers diagnostic approach for the acutely dizzy patient derives from current best evidence and offers the potential to reduce misdiagnosis while simultaneously decreases diagnostic test overuse, unnecessary hospitalization, and incorrect treatments.

Sudden Hearing Loss with Vertigo Portends Greater Stroke Risk Than Sudden Hearing Loss or Vertigo Alone.

BACKGROUND: Because it is unknown whether sudden hearing loss (SHL) in acute vertigo is a "benign" sign (reflecting ear disease) or a "dangerous" sign (reflecting stroke), we sought to compare long-term stroke risk among patients with (1) "SHL with vertigo," (2) "SHL alone," and (3) "vertigo alone" using a large national health-care database. METHODS: Patients with first-incident SHL (International Classification of Diseases, Ninth Edition, Clinical Modification [ICD-9-CM] 388.2) or vertigo (ICD-9-CM 386.x, 780.4) were identified from the National Health Insurance Research Database of Taiwan (2002-2009). We defined SHL with vertigo as a vertigo-related diagnosis ±30 days from the index SHL event. SHL without a temporally proximate vertigo diagnosis was considered SHL alone. The vertigo-alone group had no SHL diagnosis. All the patients were followed up until stroke, death, withdrawal from the database, or current end of the database (December 31, 2012) for a minimum period of 3 years. The hazards of stroke were compared across groups. RESULTS: We studied 218,656 patients (678 SHL with vertigo, 1998 with SHL alone, and 215,980 with vertigo alone). Stroke rates at study end were 5.5% (SHL with vertigo), 3.0% (SHL alone), and 3.9% (vertigo alone). Stroke hazards were higher in SHL with vertigo than in SHL alone (hazard ratio [HR], 1.93; 95% confidence interval [CI], 1.28-2.91) and in vertigo alone (HR, 1.63; 95% CI, 1.18-2.25). Defining a narrower window between SHL and vertigo (±3 days) increased the hazards. CONCLUSIONS: The combination of SHL plus vertigo in close temporal proximity is associated with increased subsequent stroke risk over SHL alone and vertigo alone. This suggests that SHL in patients with vertigo is not necessarily a benign peripheral vestibular sign.

The video head impulse test during post-rotatory nystagmus: physiology and clinical implications.

The aim of this study was to test the effects of a sustained nystagmus on the head impulse response of the vestibulo-ocular reflex (VOR) in healthy subjects. VOR gain (slow-phase eye velocity/head velocity) was measured using video head impulse test goggles. Acting as a surrogate for a spontaneous nystagmus (SN), a post-rotatory nystagmus (PRN) was elicited after a sustained, constant-velocity rotation, and then head impulses were applied. 'Raw' VOR gain, uncorrected for PRN, in healthy subjects in response to head impulses with peak velocities in the range of 150°/s-250°/s was significantly increased (as reflected in an increase in the slope of the gain versus head velocity relationship) after inducing PRN with slow phases of nystagmus of high intensity (>30°/s) in the same but not in the opposite direction as the slow-phase response induced by the head impulses. The values of VOR gain themselves, however, remained in the normal range with slow-phase velocities of PRN < 30°/s. Finally, quick phases of PRN were suppressed during the first 20-160 ms of a head impulse; the time frame of suppression depended on the direction of PRN but not on the duration of the head impulse. Our results in normal subjects suggest that VOR gains measured using head impulses may have to be corrected for any superimposed SN when the slow-phase velocity of nystagmus is relatively high and the peak velocity of the head movements is relatively low. The suppression of quick phases during head impulses may help to improve steady fixation during rapid head movements.

Compensatory saccades benefit from prediction during head impulse testing in early recovery from vestibular deafferentation.

The head impulse test (HIT) can identify a deficient vestibulo-ocular reflex (VOR) by the compensatory saccade (CS) generated once the head stops moving. The inward HIT is considered safer than the outward HIT, yet might have an oculomotor advantage given that the subject would presumably know the direction of head rotation. Here, we compare CS latencies following inward (presumed predictable) and outward (more unpredictable) HITs after acute unilateral vestibular nerve deafferentation. Seven patients received inward and outward HITs delivered at six consecutive postoperative days (POD) and again at POD 30. All head impulses were recorded by portable video-oculography. CS included those occurring during (covert) or after (overt) head rotation. Inward HITs included mean CS latencies (183.48 ms ± 4.47 SE) that were consistently shorter than those generated during outward HITs in the first 6 POD (p = 0.0033). Inward HITs induced more covert saccades compared to outward HITs, acutely. However, by POD 30 there were no longer any differences in latencies or proportions of CS and direction of head rotation. Patients with acute unilateral vestibular loss likely use predictive cues of head direction to elicit early CS to keep the image centered on the fovea. In acute vestibular hypofunction, inwardly applied HITs may risk a preponderance of covert saccades, yet this difference largely disappears within 30 days. Advantages of inwardly applied HITs are discussed and must be balanced against the risk of a false-negative HIT interpretation.

Diagnosing Stroke in Acute Vertigo: The HINTS Family of Eye Movement Tests and the Future of the "Eye ECG".

Patients who present to the emergency department with symptoms of acute vertigo or dizziness are frequently misdiagnosed. Missed opportunities to promptly treat dangerous strokes can result in poor clinical outcomes. Inappropriate testing and incorrect treatments for those with benign peripheral vestibular disorders leads to patient harm and unnecessary costs. Over the past decade, novel bedside approaches to diagnose patients with the acute vestibular syndrome have been developed and refined. A battery of three bedside tests of ocular motor physiology known as "HINTS" (head impulse, nystagmus, test of skew) has been shown to identify acute strokes more accurately than even magnetic resonance imaging with diffusion-weighted imaging (MRI-DWI) when applied in the early acute period by eye-movement specialists. Recent advances in lightweight, high-speed video-oculography (VOG) technology have made possible a future in which HINTS might be applied by nonspecialists in frontline care settings using portable VOG. Use of technology to measure eye movements (VOG-HINTS) to diagnose stroke in the acute vestibular syndrome is analogous to the use of electrocardiography (ECG) to diagnose myocardial infarction in acute chest pain. This "eye ECG" approach could transform care for patients with acute vertigo and dizziness around the world. In the United States alone, successful implementation would likely result in improved quality of emergency care for hundreds of thousands of peripheral vestibular patients and tens of thousands of stroke patients, as well as an estimated national health care savings of roughly $1 billion per year. In this article, the authors review the origins of the HINTS approach, empiric evidence and pathophysiologic principles supporting its use, and possible uses for the eye ECG in teleconsultation, teaching, and triage.

Quantifying the vestibulo-ocular reflex with video-oculography: nature and frequency of artifacts.

Video-oculography devices are now used to quantify the vestibulo-ocular reflex (VOR) at the bedside using the head impulse test (HIT). Little is known about the impact of disruptive phenomena (e.g. corrective saccades, nystagmus, fixation losses, eye-blink artifacts) on quantitative VOR assessment in acute vertigo. This study systematically characterized the frequency, nature, and impact of artifacts on HIT VOR measures. From a prospective study of 26 patients with acute vestibular syndrome (16 vestibular neuritis, 10 stroke), we classified findings using a structured coding manual. Of 1,358 individual HIT traces, 72% had abnormal disruptive saccades, 44% had at least one artifact, and 42% were uninterpretable. Physicians using quantitative recording devices to measure head impulse VOR responses for clinical diagnosis should be aware of the potential impact of disruptive eye movements and measurement artifacts.

Diagnostic Errors in a PICU: Insights From the Morbidity and Mortality Conference.

OBJECTIVES: To describe diagnostic errors identified among patients discussed at a PICU morbidity and mortality conference in terms of Goldman classification, medical category, severity, preventability, contributing factors, and occurrence in the diagnostic process. DESIGN: Retrospective record review of morbidity and mortality conference agendas, patient charts, and autopsy reports. SETTING: Single tertiary referral PICU in Baltimore, MD. PATIENTS: Ninety-six patients discussed at the PICU morbidity and mortality conference from November 2011 to December 2012. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Eighty-nine of 96 patients (93%) discussed at the PICU morbidity and mortality conference had at least one identified safety event. A total of 377 safety events were identified. Twenty patients (21%) had identified misdiagnoses, comprising 5.3% of all safety events. Out of 20 total diagnostic errors identified, 35% were discovered at autopsy while 55% were reported primarily through the morbidity and mortality conference. Almost all diagnostic errors (95%) could have had an impact on patient survival or safety. Forty percent of errors did not cause actual patient harm, but 25% were severe enough to have potentially contributed to death (40% no harm vs 35% some harm vs 25% possibly contributed to death). Half of the diagnostic errors (50%) were rated as preventable. There were slightly more system-related factors (40%) solely contributing to diagnostic errors compared with cognitive factors (20%); however, 35% had both system and cognitive factors playing a role. Most errors involved vascular (35%) followed by neurologic (30%) events. CONCLUSIONS: Diagnostic errors in the PICU are not uncommon and potentially cause patient harm. Most appear to be preventable by targeting both cognitive- and system-related contributing factors. Prospective studies are needed to further determine how and why diagnostic errors occur in the PICU and what interventions would likely be effective for prevention.

Diagnostic errors in the pediatric and neonatal ICU: a systematic review.

OBJECTIVE: Diagnostic errors lead to preventable hospital morbidity and mortality. ICU patients may be at particularly high risk for misdiagnosis. Little is known about misdiagnosis in pediatrics, including PICU and neonatal ICU. We sought to assess diagnostic errors in PICU and neonatal ICU settings by systematic review. DATA SOURCES: We searched PubMed, Embase, CINAHL, and Cochrane. STUDY SELECTION: We identified observational studies reporting autopsy-confirmed diagnostic errors in PICU or neonatal ICU using standard Goldman criteria. DATA EXTRACTION: We abstracted patient characteristics, diagnostic error description, rates and error classes using standard Goldman criteria for autopsy misdiagnoses and calculated descriptive statistics. DATA SYNTHESIS: We screened 329 citations, examined 79 full-text articles, and included 13 studies (seven PICU; six neonatal ICU). The PICU studies examined a total of 1,063 deaths and 498 autopsies. Neonatal ICU studies examined a total of 2,124 neonatal deaths and 1,259 autopsies. Major diagnostic errors were found in 19.6% of autopsied PICU and neonatal ICU deaths (class I, 4.5%; class II, 15.1%). Class I (potentially lethal) misdiagnoses in the PICU (43% infections, 37% vascular) and neonatal ICU (62% infections, 21% congenital/metabolic) differed slightly. Although missed infections were most common in both settings, missed vascular events were more common in the PICU and missed congenital conditions in the neonatal ICU. CONCLUSION: Diagnostic errors in PICU/neonatal ICU populations are most commonly due to infection. Further research is needed to better quantify pediatric intensive care-related misdiagnosis and to define potential strategies to reduce their frequency or mitigate misdiagnosis-related harm.

Intraventricular thrombolysis in intracerebral hemorrhage requiring ventriculostomy: a decade-long real-world experience.

BACKGROUND AND PURPOSE: Intraventricular thrombolysis (IVT) is a promising treatment in facilitating intraventricular clot resolution after intraventricular hemorrhage. We examined in-hospital outcomes and resource utilization after thrombolysis in patients with intraventricular hemorrhage requiring ventriculostomy in a real-world setting. METHODS: We identified adult patients with primary diagnosis of nontraumatic intracerebral hemorrhage requiring ventriculostomy from the Nationwide Inpatient Sample from 2002 to 2011. We compared demographic and hospital characteristics, comorbidities, inpatient outcomes, and resource utilization measures between patients treated with IVT and those managed with ventriculostomy, but without IVT. Population estimates were extrapolated using standard Nationwide Inpatient Sample weighting algorithms. RESULTS: We included 34 044 patients in the analysis, of whom 1133 (3.3%) received IVT. The thrombolysis group had significantly lower inpatient mortality (32.4% versus 41.6%; P=0.001) and it remained lower after controlling for baseline demographics, hospital characteristics, comorbidity, case severity, and withdrawal of care status (adjusted odds ratio, 0.670; 95% confidence interval, 0.520-0.865; P=0.002). There was a trend toward favorable discharge (home or rehabilitation) among the thrombolysis cohort (adjusted odds ratio, 1.335; 95% confidence interval, 0.983-1.812; P=0.064). The adjusted rates of bacterial meningitis and ventricular shunt placement were similar between groups. The thrombolysis group had longer length of stay and higher inflation-adjusted cost of care, but cost of care per day length of stay was similar to the non-IVT group. CONCLUSIONS: IVT for intracerebral hemorrhage requiring ventriculostomy resulted in lower inpatient mortality and a trend toward favorable discharge outcome with similar rates of inpatient complications compared with the non-IVT group.

Assessing clinical reasoning skills following a virtual patient dizziness curriculum.

OBJECTIVES: Dizziness is a common medical symptom that is frequently misdiagnosed. While virtual patient (VP) education has been shown to improve diagnostic accuracy for dizziness as assessed by VPs, trainee performance has not been assessed on human subjects. The study aimed to assess whether internal medicine (IM) interns after training on a VP-based dizziness curriculum using a deliberate practice framework would demonstrate improved clinical reasoning when assessed in an objective structured clinical examination (OSCE). METHODS: All available interns volunteered and were randomized 2:1 to intervention (VP education) vs. control (standard clinical teaching) groups. This quasi-experimental study was conducted at one academic medical center from January to May 2021. Both groups completed pre-posttest VP case assessments (scored as correct diagnosis across six VP cases) and participated in an OSCE done 6 weeks later. The OSCEs were recorded and assessed using a rubric that was systematically developed and validated. RESULTS: Out of 21 available interns, 20 participated. Between intervention (n=13) and control (n=7), mean pretest VP diagnostic accuracy scores did not differ; the posttest VP scores improved for the intervention group (3.5 [SD 1.3] vs. 1.6 [SD 0.8], p=0.007). On the OSCE, the means scores were higher in the intervention (n=11) compared to control group (n=4) for physical exam (8.4 [SD 4.6] vs. 3.9 [SD 4.0], p=0.003) and total rubric score (43.4 [SD 12.2] vs. 32.6 [SD 11.3], p=0.04). CONCLUSIONS: The VP-based dizziness curriculum resulted in improved diagnostic accuracy among IM interns with enhanced physical exam skills retained at 6 weeks post-intervention.

Burden of serious harms from diagnostic error in the USA.

BACKGROUND: Diagnostic errors cause substantial preventable harms worldwide, but rigorous estimates for total burden are lacking. We previously estimated diagnostic error and serious harm rates for key dangerous diseases in major disease categories and validated plausible ranges using clinical experts. OBJECTIVE: We sought to estimate the annual US burden of serious misdiagnosis-related harms (permanent morbidity, mortality) by combining prior results with rigorous estimates of disease incidence. METHODS: Cross-sectional analysis of US-based nationally representative observational data. We estimated annual incident vascular events and infections from 21.5 million (M) sampled US hospital discharges (2012-2014). Annual new cancers were taken from US-based registries (2014). Years were selected for coding consistency with prior literature. Disease-specific incidences for 15 major vascular events, infections and cancers ('Big Three' categories) were multiplied by literature-based rates to derive diagnostic errors and serious harms. We calculated uncertainty estimates using Monte Carlo simulations. Validity checks included sensitivity analyses and comparison with prior published estimates. RESULTS: Annual US incidence was 6.0 M vascular events, 6.2 M infections and 1.5 M cancers. Per 'Big Three' dangerous disease case, weighted mean error and serious harm rates were 11.1% and 4.4%, respectively. Extrapolating to all diseases (including non-'Big Three' dangerous disease categories), we estimated total serious harms annually in the USA to be 795 000 (plausible range 598 000-1 023 000). Sensitivity analyses using more conservative assumptions estimated 549 000 serious harms. Results were compatible with setting-specific serious harm estimates from inpatient, emergency department and ambulatory care. The 15 dangerous diseases accounted for 50.7% of total serious harms and the top 5 (stroke, sepsis, pneumonia, venous thromboembolism and lung cancer) accounted for 38.7%. CONCLUSION: An estimated 795 000 Americans become permanently disabled or die annually across care settings because dangerous diseases are misdiagnosed. Just 15 diseases account for about half of all serious harms, so the problem may be more tractable than previously imagined.

Computable phenotype for diagnostic error: developing the data schema for application of symptom-disease pair analysis of diagnostic error (SPADE).

OBJECTIVES: Diagnostic errors are the leading cause of preventable harm in clinical practice. Implementable tools to quantify and target this problem are needed. To address this gap, we aimed to generalize the Symptom-Disease Pair Analysis of Diagnostic Error (SPADE) framework by developing its computable phenotype and then demonstrated how that schema could be applied in multiple clinical contexts. METHODS: We created an information model for the SPADE processes, then mapped data fields from electronic health records (EHR) and claims data in use to that model to create the SPADE information model (intention) and the SPADE computable phenotype (extension). Later we validated the computable phenotype and tested it in four case studies in three different health systems to demonstrate its utility. RESULTS: We mapped and tested the SPADE computable phenotype in three different sites using four different case studies. We showed that data fields to compute an SPADE base measure are fully available in the EHR Data Warehouse for extraction and can operationalize the SPADE framework from provider and/or insurer perspective, and they could be implemented on numerous health systems for future work in monitor misdiagnosis-related harms. CONCLUSIONS: Data for the SPADE base measure is readily available in EHR and administrative claims. The method of data extraction is potentially universally applicable, and the data extracted is conveniently available within a network system. Further study is needed to validate the computable phenotype across different settings with different data infrastructures.

Quantitative video-oculography to help diagnose stroke in acute vertigo and dizziness: toward an ECG for the eyes.

BACKGROUND AND PURPOSE: Strokes can be distinguished from benign peripheral causes of acute vestibular syndrome using bedside oculomotor tests (head impulse test, nystagmus, test-of-skew). Using head impulse test, nystagmus, test-of-skew is more sensitive and less costly than early magnetic resonance imaging for stroke diagnosis in acute vestibular syndrome but requires expertise not routinely available in emergency departments. We sought to begin standardizing the head impulse test, nystagmus, test-of-skew diagnostic approach for eventual emergency department use through the novel application of a portable video-oculography device measuring vestibular physiology in real time. This approach is conceptually similar to ECG to diagnose acute cardiac ischemia. METHODS: Proof-of-concept study (August 2011 to June 2012). We recruited adult emergency department patients with acute vestibular syndrome defined as new, persistent vertigo/dizziness, nystagmus, and (1) nausea/vomiting, (2) head motion intolerance, or (3) new gait unsteadiness. We recorded eye movements, including quantitative horizontal head impulse testing of vestibulo-ocular-reflex function. Two masked vestibular experts rated vestibular findings, which were compared with final radiographic gold-standard diagnoses. Masked neuroimaging raters determined stroke or no stroke using magnetic resonance imaging of the brain with diffusion-weighted imaging obtained 48 hours to 7 days after symptom onset. RESULTS: We enrolled 12 consecutive patients who underwent confirmatory magnetic resonance imaging. Mean age was 61 years (range 30-73), and 10 were men. Expert-rated video-oculography-based head impulse test, nystagmus, test-of-skew examination was 100% accurate (6 strokes, 6 peripheral vestibular). CONCLUSIONS: Device-based physiological diagnosis of vertebrobasilar stroke in acute vestibular syndrome should soon be possible. If confirmed in a larger sample, this bedside eye ECG approach could eventually help fulfill a critical need for timely, accurate, efficient diagnosis in emergency department patients with vertigo or dizziness who are at high risk for stroke.