Risk of stroke after emergency department visits for neurologic complaints

Analysis of Telestroke Usage in Rural Critical Access Emergency Departments

Introduction: Telestroke is an effective strategy to increase appropriate stroke treatments among patients in resource-limited environments. Despite the well-documented benefits of telestroke, there is limited literature regarding its utilization. The purposes of this study are: (1) determine the percentage of potential stroke patients who generate a telestroke consult in rural critical access hospitals (CAHs) and (2) validate an electronic medical record (EMR)-derived report as a stroke screen. Methods: This retrospective chart review analyzed patients presenting between September 1, 2020 and February 1, 2021 to three CAHs. Visits with triage complaints suggesting acute ischemic stroke (AIS)/transient ischemic attack (TIA) were pooled for analysis using an EMR-derived report. Patients with confirmed AIS/TIA at discharge over this period were used to validate the EMR tool. Results: The EMR report pooled 252 possible AIS/TIA visits out of 12,685 emergency department visits for analysis. It had a specificity of 98.78% and sensitivity of 58.06%. Of the 252 visits, 12.7% met telestroke criteria and 38.89% received telestroke evaluation. Among these, a definite diagnosis of AIS/TIA was made in 92.86%. Of the remaining population who met criteria but didn't undergo consultation, 61.11% were diagnosed with AIS/TIA at discharge. Conclusion: This study provides novel characterization of stroke presentations and telestroke in rural CAHs. The EMR-derived report is a reasonable tool to concentrate potential AIS/TIA cases for review and resource allocation but is not sensitive enough to detect stroke as a stand-alone tool. The majority (56%) of eligible patients did not undergo telestroke consultation. Future studies are critical to further understand reasons contributing to this.

Optimizing measurement of misdiagnosis-related harms using symptom-disease pair analysis of diagnostic error (SPADE): comparison groups to maximize SPADE validity

Diagnostic errors in medicine represent a significant public health problem but continue to be challenging to measure accurately, reliably, and efficiently. The recently developed Symptom-Disease Pair Analysis of Diagnostic Error (SPADE) approach measures misdiagnosis related harms using electronic health records or administrative claims data. The approach is clinically valid, methodologically sound, statistically robust, and operationally viable without the requirement for manual chart review. This paper clarifies aspects of the SPADE analysis to assure that researchers apply this method to yield valid results with a particular emphasis on defining appropriate comparator groups and analytical strategies for balancing differences between these groups. We discuss four distinct types of comparators (intra-group and inter-group for both look-back and look-forward analyses), detailing the rationale for choosing one over the other and inferences that can be drawn from these comparative analyses. Our aim is that these additional analytical practices will improve the validity of SPADE and related approaches to quantify diagnostic error in medicine.

Prevalence of neurological complaints among emergency department patients with severe hypertension

OBJECTIVE

Severe hypertension can accompany neurological symptoms without obvious signs of target organ damage. However, acute cerebrovascular events can also be a cause and consequence of severe hypertension. We therefore use US population-level data to determine prevalence and clinical characteristics of patients with severe hypertension and neurological complaints.

METHODS

We used nationally representative data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) collected in 2016-2019 to identify adult ED patients with severely elevated blood pressure (BP) defined as systolic BP ≥ 180 mmHg and/or diastolic BP ≥120 mmHg. We used ED reason for visit data fields to define neurological complaints and used diagnosis data fields to define acute target organ damage. We applied survey visit weights to obtain national estimates.

RESULTS

Based on 5083 observations, an estimated 40.4 million patients (95% CI: 37.5-43.0 million) in EDs nationwide from 2016 to 2019 had severe hypertension, equating to 6.1% (95% CI: 5.7-6.5%) of all ED visits. Only 2.8% (95% CI: 2.0-3.9%) of ED patients with severe hypertension were diagnosed with acute cerebrovascular disease; hypertensive urgency was diagnosed in 92.0% (95% CI: 90.3-93.4%). Neurological complaints were frequent in both patients with (75.6%) and without (19.9%) cerebrovascular diagnoses. Hypertensive urgency patients with neurological complaints were more often older, female, had prior stroke/TIA, and had neuroimaging than patients without these complaints. Non-migraine headache and vertigo were the most common neurological complaints recorded.

CONCLUSION

In a nationally representative survey, one-in-sixteen ED patients had severely elevated BP and one-fifth of those patients had neurological complaints.

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.

Emergency medicine physicians' perspectives on diagnostic accuracy in neurology: a qualitative study

OBJECTIVES

We sought to understand the knowledge, attitudes, and beliefs of emergency medicine (EM) physicians towards non-specific neurological conditions and the use of clinical decision support (CDS) to improve diagnostic accuracy.

METHODS

We conducted semi-structured interviews of EM physicians at four emergency departments (EDs) affiliated with a single US healthcare system. Interviews were conducted until thematic saturation was achieved. Conventional content analysis was used to identify themes related to EM physicians' perspectives on acute diagnostic neurology; directed content analysis was used to explore views regarding CDS. Each interview transcript was independently coded by two researchers using an iteratively refined codebook with consensus-based resolution of coding differences.

RESULTS

We identified two domains regarding diagnostic safety: (1) challenges unique to neurological complaints and (2) challenges in EM more broadly. Themes relevant to neurology included: (1) knowledge gaps and uncertainty, (2) skepticism about neurology, (3) comfort with basic as opposed to detailed neurological examination, and (4) comfort with non-neurological diseases. Themes relevant to diagnostic decision making in the ED included: (1) cognitive biases, (2) ED system/environmental issues, (3) patient barriers, (4) comfort with diagnostic uncertainty, and (5) concerns regarding diagnostic error identification and measurement. Most participating EM physicians were enthusiastic about the potential for well-designed CDS to improve diagnostic accuracy for non-specific neurological complaints.

CONCLUSIONS

Physicians identified diagnostic challenges unique to neurological diseases as well as issues related more generally to diagnostic accuracy in EM. These physician-reported issues should be accounted for when designing interventions to improve ED diagnostic accuracy.

Validation of an electronic trigger to measure missed diagnosis of stroke in emergency departments

OBJECTIVE

Diagnostic errors are major contributors to preventable patient harm. We validated the use of an electronic health record (EHR)-based trigger (e-trigger) to measure missed opportunities in stroke diagnosis in emergency departments (EDs).

METHODS

Using two frameworks, the Safer Dx Trigger Tools Framework and the Symptom-disease Pair Analysis of Diagnostic Error Framework, we applied a symptom-disease pair-based e-trigger to identify patients hospitalized for stroke who, in the preceding 30 days, were discharged from the ED with benign headache or dizziness diagnoses. The algorithm was applied to Veteran Affairs National Corporate Data Warehouse on patients seen between 1/1/2016 and 12/31/2017. Trained reviewers evaluated medical records for presence/absence of missed opportunities in stroke diagnosis and stroke-related red-flags, risk factors, neurological examination, and clinical interventions. Reviewers also estimated quality of clinical documentation at the index ED visit.

RESULTS

We applied the e-trigger to 7,752,326 unique patients and identified 46,931 stroke-related admissions, of which 398 records were flagged as trigger-positive and reviewed. Of these, 124 had missed opportunities (positive predictive value for "missed" = 31.2%), 93 (23.4%) had no missed opportunity (non-missed), 162 (40.7%) were miscoded, and 19 (4.7%) were inconclusive. Reviewer agreement was high (87.3%, Cohen's kappa = 0.81). Compared to the non-missed group, the missed group had more stroke risk factors (mean 3.2 vs 2.6), red flags (mean 0.5 vs 0.2), and a higher rate of inadequate documentation (66.9% vs 28.0%).

CONCLUSION

In a large national EHR repository, a symptom-disease pair-based e-trigger identified missed diagnoses of stroke with a modest positive predictive value, underscoring the need for chart review validation procedures to identify diagnostic errors in large data sets.

Head Computed tomography during emergency department treat-and-release visit for headache is associated with increased risk of subsequent cerebrovascular disease hospitalization

OBJECTIVES

The occurrence of head computed tomography (HCT) at emergency department (ED) visit for non-specific neurological symptoms has been associated with increased subsequent stroke risk and may be a marker of diagnostic error. We evaluate whether HCT occurrence among ED headache patients is associated with increased subsequent cerebrovascular disease risk.

METHODS

We conducted a retrospective cohort study of consecutive adult patients with headache who were discharged home from the ED (ED treat-and-release visit) at one multicenter institution. Patients with headache were defined as those with primary ICD-9/10-CM discharge diagnoses codes for benign headache from 9/1/2013-9/1/2018. The primary outcome of cerebrovascular disease hospitalization was identified using ICD-9/10-CM codes and confirmed via chart review. We matched headache patients who had a HCT (exposed) to those who did not have a HCT (unexposed) in the ED in a one-to-one fashion using propensity score methods.

RESULTS

Among the 28,121 adult patients with ED treat-and-release headache visit, 45.6% (n=12,811) underwent HCT. A total of 0.4% (n=111) had a cerebrovascular hospitalization within 365 days of index visit. Using propensity score matching, 80.4% (n=10,296) of exposed patients were matched to unexposed. Exposed patients had increased risk of cerebrovascular hospitalization at 365 days (RR: 1.65: 95% CI: 1.18-2.31) and 180 days (RR: 1.62; 95% CI: 1.06-2.49); risk of cerebrovascular hospitalization was not increased at 90 or 30 days.

CONCLUSIONS

Having a HCT performed at ED treat-and-release headache visit is associated with increased risk of subsequent cerebrovascular disease. Future work to improve cerebrovascular disease prevention strategies in this subset of headache patients is warranted.

Factors associated with hospitalization for ischemic stroke and TIA following an emergency department headache visit

BACKGROUND

Misdiagnosis of cerebrovascular disease among Emergency Department (ED) patients with headache has been reported. We hypothesized that markers of substandard diagnostic processes would be associated with subsequent ischemic cerebrovascular events among patients discharged from the ED with a headache diagnosis even after adjusting for demographic variables and medical history.

METHODS

We conducted a case-control study of adult ED patients diagnosed with a primary headache disorder at Montefiore Medical Center from 9/1/2013-9/1/2018. Cases were defined as patients hospitalized for an ischemic stroke or TIA within 365 days of their index ED visit. Control patients were defined as those who lacked a subsequent hospitalization for cerebrovascular disease. Pre-specified demographic, clinical, and diagnostic process factors were compared between groups; conditional logistic regression was used to assess the separate and joint influence of baseline features on risk of cerebral ischemia.

RESULTS

A total of 93 consecutive headache patients with a subsequent ischemic stroke/TIA hospitalization were matched to 93 controls (n = 186). Cases were older than controls and more likely to have traditional cerebrovascular risk factors. Neurological consultation was obtained more often for cases (13% vs. 4%; P = 0.03), cases were in the ED for longer (6 vs. 5 h, P = 0.03), and more frequently received neuroimaging (80% vs. 48%; P < 0.0001). Rates of neurological examination, documented differential diagnoses, and clear discharge follow up plans were similar between cases and controls. In our conditional logistic regression model, only history of prior stroke/TIA was associated with increased odds of subsequent cerebral ischemia.

CONCLUSION

Factors associated with diagnostic process failures did not increase the odds of subsequent ischemic stroke/TIA hospitalization following ED headache visit in our study.