Rate of sepsis hospitalizations after misdiagnosis in adult emergency department patients: a look-forward analysis with administrative claims data using Symptom-Disease Pair Analysis of Diagnostic Error (SPADE) methodology in an integrated health system.

OBJECTIVES: Delays in sepsis diagnosis can increase morbidity and mortality. Previously, we performed a Symptom-Disease Pair Analysis of Diagnostic Error (SPADE) "look-back" analysis to identify symptoms at risk for delayed sepsis diagnosis. We found treat-and-release emergency department (ED) encounters for fluid and electrolyte disorders (FED) and altered mental status (AMS) were associated with downstream sepsis hospitalizations. In this "look-forward" analysis, we measure the potential misdiagnosis-related harm rate for sepsis among patients with these symptoms. METHODS: Retrospective cohort study using electronic health record and claims data from Kaiser Permanente Mid-Atlantic States (2013-2018). Patients ≥18 years with ≥1 treat-and-release ED encounter for FED or AMS were included. Observed greater than expected sepsis hospitalizations within 30 days of ED treat-and-release encounters were considered potential misdiagnosis-related harms. Temporal analyses were employed to differentiate case and comparison (superficial injury/contusion ED encounters) cohorts. RESULTS: There were 4,549 treat-and-release ED encounters for FED or AMS, 26 associated with a sepsis hospitalization in the next 30 days. The observed (0.57%) minus expected (0.13%) harm rate was 0.44% (absolute) and 4.5-fold increased over expected (relative). There was a spike in sepsis hospitalizations in the week following FED/AMS ED visits. There were fewer sepsis hospitalizations and no spike in admissions in the week following superficial injury/contusion ED visits. Potentially misdiagnosed patients were older and more medically complex. CONCLUSIONS: Potential misdiagnosis-related harms from sepsis are infrequent but measurable using SPADE. This look-forward analysis validated our previous look-back study, demonstrating the SPADE approach can be used to study infectious disease syndromes.

Missed acute myocardial infarction in the emergency department-standardizing measurement of misdiagnosis-related harms using the SPADE method.

OBJECTIVES: Diagnostic error is a serious public health problem. Measuring diagnostic performance remains elusive. We sought to measure misdiagnosis-related harms following missed acute myocardial infarctions (AMI) in the emergency department (ED) using the symptom-disease pair analysis of diagnostic error (SPADE) method. METHODS: Retrospective administrative data analysis (2009-2017) from a single, integrated health system using International Classification of Diseases (ICD) coded discharge diagnoses. We looked back 30 days from AMI hospitalizations for antecedent ED treat-and-release visits to identify symptoms linked to probable missed AMI (observed > expected). We then looked forward from these ED discharge diagnoses to identify symptom-disease pair misdiagnosis-related harms (AMI hospitalizations within 30-days, representing diagnostic adverse events). RESULTS: A total of 44,473 AMI hospitalizations were associated with 2,874 treat-and-release ED visits in the prior 30 days. The top plausibly-related ED discharge diagnoses were "chest pain" and "dyspnea" with excess treat-and-release visit rates of 9.8% (95% CI 8.5-11.2%) and 3.4% (95% CI 2.7-4.2%), respectively. These represented 574 probable missed AMIs resulting in hospitalization (adverse event rate per AMI 1.3%, 95% CI 1.2-1.4%). Looking forward, 325,088 chest pain or dyspnea ED discharges were followed by 508 AMI hospitalizations (adverse event rate per symptom discharge 0.2%, 95% CI 0.1-0.2%). CONCLUSIONS: The SPADE method precisely quantifies misdiagnosis-related harms from missed AMIs using administrative data. This approach could facilitate future assessment of diagnostic performance across health systems. These results correspond to ∼10,000 potentially-preventable harms annually in the US. However, relatively low error and adverse event rates may pose challenges to reducing harms for this ED symptom-disease pair.

Conversion of upbeat to downbeat nystagmus in Wernicke encephalopathy.

OBJECTIVE: To explain (1) why an initial upbeat nystagmus (UBN) converts to a permanent downbeat nystagmus (DBN) in Wernicke encephalopathy (WE) and (2) why convergence and certain vestibular provocative maneuvers may transiently switch UBN to DBN. METHODS: Following a literature review and study of our 2 patients, we develop hypotheses for the unusual patterns of vertical nystagmus in WE. RESULTS: Our overarching hypothesis is that there is a selective vulnerability and a selective recovery from thiamine deficiency of neurons within brainstem gaze-holding networks. Furthermore, since the circuits affected in WE are commonly paraventricular, especially medially, just under the floor of the fourth ventricle where lie structures important for control of vertical gaze, we suggest the patterns of involvement in WE also reflect a breakdown in vulnerable areas of the blood-brain barrier. Many of the initial deficits of our patients improved over time, but their DBN did not. Irreversible changes in paramedian tract neurons, which project to the cerebellar flocculus, may be the cause. Here we suggest that conversion of UBN to permanent DBN points to thiamine deficiency and may argue for a chronic, nonprogressive DBN/truncal ataxia syndrome. Finally, we posit that the transient switch of UBN to DBN reflects abnormal processing of otolith information about linear acceleration, and often points to a diagnosis of WE. CONCLUSION: Recognizing the unusual patterns of transient switching and then permanent conversion of UBN to DBN in WE is vital since long-term disability from WE may be prevented by timely, parenteral high-dose thiamine.

Are health care provider organizations ready to tackle diagnostic error? A survey of Leapfrog-participating hospitals.

BACKGROUND: A 2015 National Academy of Medicine report on improving diagnosis in health care made recommendations for direct action by hospitals and health systems. Little is known about how health care provider organizations are addressing diagnostic safety/quality. METHODS: This study is an anonymous online survey of safety professionals from US hospitals and health systems in July-August 2016. The survey was sent to those attending a Leapfrog Group webinar on misdiagnosis (n=188). The instrument was focused on knowledge, attitudes, and capability to address diagnostic errors at the institutional level. RESULTS: Overall, 61 (32%) responded, including community hospitals (42%), integrated health networks (25%), and academic centers (21%). Awareness was high, but commitment and capability were low (31% of leaders understand the problem; 28% have sufficient safety resources; and 25% have made diagnosis a top institutional safety priority). Ongoing efforts to improve diagnostic safety were sparse and mostly included root cause analysis and peer review feedback around diagnostic errors. The top three barriers to addressing diagnostic error were lack of awareness of the problem, lack of measures of diagnostic accuracy and error, and lack of feedback on diagnostic performance. The top two tools viewed as critically important for locally tackling the problem were routine feedback on diagnostic performance and culture change to emphasize diagnostic safety. CONCLUSIONS: Although hospitals and health systems appear to be aware of diagnostic errors as a major safety imperative, most organizations (even those that appear to be making a strong commitment to patient safety) are not yet doing much to improve diagnosis. Going forward, efforts to activate health care organizations will be essential to improving diagnostic safety.