Browsing by Author "Holmstedt, Christine"

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    Recent Vitamin K Antagonist Use and Intracranial Hemorrhage After Endovascular Thrombectomy for Acute Ischemic Stroke
    (American Medical Association, 2023) Mac Grory, Brian; Holmes, DaJuanicia N.; Matsouaka, Roland A.; Shah, Shreyansh; Chang, Cherylee W. J.; Rison, Richard; Jindal, Jenelle; Holmstedt, Christine; Logan, William R.; Corral, Candy; Mackey, Jason S.; Gee, Joey R.; Bonovich, David; Walker, James; Gropen, Toby; Benesch, Curtis; Dissin, Jonathan; Pandey, Hemant; Wang, David; Unverdorben, Martin; Hernandez, Adrian F.; Reeves, Mathew; Smith, Eric E.; Schwamm, Lee H.; Bhatt, Deepak L.; Saver, Jeffrey L.; Fonarow, Gregg C.; Peterson, Eric D.; Xian, Ying; Neurology, School of Medicine
    Importance: Use of oral vitamin K antagonists (VKAs) may place patients undergoing endovascular thrombectomy (EVT) for acute ischemic stroke caused by large vessel occlusion at increased risk of complications. Objective: To determine the association between recent use of a VKA and outcomes among patients selected to undergo EVT in clinical practice. Design, setting, and participants: Retrospective, observational cohort study based on the American Heart Association's Get With the Guidelines-Stroke Program between October 2015 and March 2020. From 594 participating hospitals in the US, 32 715 patients with acute ischemic stroke selected to undergo EVT within 6 hours of time last known to be well were included. Exposure: VKA use within the 7 days prior to hospital arrival. Main outcome and measures: The primary end point was symptomatic intracranial hemorrhage (sICH). Secondary end points included life-threatening systemic hemorrhage, another serious complication, any complications of reperfusion therapy, in-hospital mortality, and in-hospital mortality or discharge to hospice. Results: Of 32 715 patients (median age, 72 years; 50.7% female), 3087 (9.4%) had used a VKA (median international normalized ratio [INR], 1.5 [IQR, 1.2-1.9]) and 29 628 had not used a VKA prior to hospital presentation. Overall, prior VKA use was not significantly associated with an increased risk of sICH (211/3087 patients [6.8%] taking a VKA compared with 1904/29 628 patients [6.4%] not taking a VKA; adjusted odds ratio [OR], 1.12 [95% CI, 0.94-1.35]; adjusted risk difference, 0.69% [95% CI, -0.39% to 1.77%]). Among 830 patients taking a VKA with an INR greater than 1.7, sICH risk was significantly higher than in those not taking a VKA (8.3% vs 6.4%; adjusted OR, 1.88 [95% CI, 1.33-2.65]; adjusted risk difference, 4.03% [95% CI, 1.53%-6.53%]), while those with an INR of 1.7 or lower (n = 1585) had no significant difference in the risk of sICH (6.7% vs 6.4%; adjusted OR, 1.24 [95% CI, 0.87-1.76]; adjusted risk difference, 1.13% [95% CI, -0.79% to 3.04%]). Of 5 prespecified secondary end points, none showed a significant difference across VKA-exposed vs VKA-unexposed groups. Conclusions and relevance: Among patients with acute ischemic stroke selected to receive EVT, VKA use within the preceding 7 days was not associated with a significantly increased risk of sICH overall. However, recent VKA use with a presenting INR greater than 1.7 was associated with a significantly increased risk of sICH compared with no use of anticoagulants.
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    Task, Usability, and Error Analyses of Ambulance-based Telemedicine for Stroke Care
    (Taylor & Francis, 2021) Rogers, Hunter; Madathil, Kapil Chalil; Joseph, Anjali; McNeese, Nathan; Holmstedt, Christine; Holden, Richard; McElligott, James T.; Medicine, School of Medicine
    Past research has established that telemedicine improves stroke care through decreased time to treatment and more accurate diagnoses. The goals of this study were to 1) study how clinicians complete stroke assessment using a telemedicine system integrated in ambulances, 2) determine potential errors and usability issues when using the system, and 3) develop recommendations to mitigate these issues. This study investigated use of a telemedicine platform to evaluate a stroke patient in an ambulance with a geographically distributed caregiving team comprised of a paramedic, nurse, and neurologist. It first determined the tasks involved based on 13 observations of a simulated stroke using 39 care providers. Based on these observational studies, a Hierarchical Task Analysis (HTA) was developed, and subsequently, a heuristic evaluation was conducted to determine the usability issues in the interface of the telemedicine system. This was followed by a Systematic Human Error Reduction and Prediction Approach (SHERPA) to determine the possibility of human error while providing care using the telemedicine work system. The results from the HTA included 6 primary subgoals categorizing the 97 tasks to complete the stroke evaluation. The heuristic evaluation found 123 unique violations to heuristics, with an average severity of 2.38. One hundred and thirty-one potential human errors were found with SHERPA, the two most common being miscommunication and selecting an incorrect option. Several recommendations are proposed, including improvement of labeling, consistent formatting, rigid or suggested formatting for data input, automation of task structure and camera movement, and audio/visual improvements to support communication.