Hospital Variation in Time to Endovascular Treatment for Ischemic Stroke: What Is the Optimal Target for Improvement?
Authors: den Hartog Sanne J. , Lingsma Hester F. , van Doormaal Pieter‐Jan , Hofmeijer Jeannette , Yo Lonneke S. F. , Majoie Charles B. L. M. , Dippel Diederik W. J. , van der Lugt Aad , Roozenbeek Bob , Dippel Diederik W. J. , van der Lugt Aad , Majoie Charles B. L. M. , Roos Yvo B. W. E. M. , van Oostenbrugge Robert J. , van Zwam Wim H. , Boiten Jelis , Vos Jan Albert , Jansen Ivo G. H. , Mulder Maxim J. H. L. , Goldhoorn Robert‐ Jan B. , Compagne Kars C. J. , Kappelhof Manon , Brouwer Josje , den Hartog Sanne J. , Hinsenveld Wouter H. , Roozenbeek Bob , van Es Adriaan C. G. M. , Emmer Bart J. , Coutinho Jonathan M. , Schonewille Wouter J. , Wermer Marieke J. H. , van Walderveen Marianne A. A. , Staals Julie , Hofmeijer Jeannette , Martens Jasper M. , Lycklama à Nijeholt Geert J. , de Bruijn Sebastiaan F. , van Dijk Lukas C. , van der Worp H. Bart , Lo Rob H. , van Dijk Ewoud J. , Boogaarts Hieronymus D. , de Vries J. , de Kort Paul L. M. , van Tuijl Julia , Peluso Jo P. , Fransen Puck , van den Berg Jan S. P. , van Hasselt Boudewijn A. A. M. , Aerden Leo A. M. , Dallinga René J. , Uyttenboogaart Maarten , Eschgi Omid , Bokkers Reinoud P. H. , Schreuder Tobien H. C. M. L. , Heijboer Roel J. J. , Keizer Koos , Yo Lonneke S. F. , den Hertog Heleen M. , Sturm Emiel J. C. , Brouwers Paul J. A. M. , Sprengers Marieke E. S. , Jenniskens Sjoerd F. M. , van den Berg René , Yoo Albert J. , Beenen Ludo F. M. , Postma Alida A. , Roosendaal Stefan D. , van der Kallen Bas F. W. , van den Wijngaard Ido R. , Bot Joost , van Doormaal Pieter‐Jan , Meijer Anton , Ghariq Elyas , van Proosdij Marc P. , Menno Krietemeijer G. , Gerrits Dick , Dinkelaar Wouter , Appelman Auke P. A. , Hammer Bas , Pegge Sjoert , van der Hoorn Anouk , Vinke Saman , Zwenneke Flach H , Lingsma Hester F. , Ghannouti Naziha el , Sterrenberg Martin , Pellikaan Wilma , Sprengers Rita , Elfrink Marjan , Simons Michelle , Vossers Marjolein , de Meris Joke , Vermeulen Tamara , Geerlings Annet , van Vemde Gina , Simons Tiny , Messchendorp Gert , Nicolaij Nynke , Bongenaar Hester , Bodde Karin , Kleijn Sandra , Lodico Jasmijn , Droste Hanneke , Wollaert Maureen , Verheesen Sabrina , Jeurrissen D. , Bos Erna , Drabbe Yvonne , Sandiman Michelle , Aaldering Nicoline , Zweedijk Berber , Vervoort Jocova , Ponjee Eva , Romviel Sharon , Kanselaar Karin , Barning Denn , Venema Esmee , Chalos Vicky , Geuskens Ralph R. , van Straaten Tim , Ergezen Saliha , Harmsma Roger R. M. , Muijres Daan , de Jong Anouk , Berkhemer Olvert A. , Boers Anna M. M. , Huguet J. , Groot P. F. C. , Mens Marieke A. , van Kranendonk Katinka R. , Treurniet Kilian M. , Tolhuisen Manon L. , Alves Heitor , Weterings Annick J. , Kirkels Eleonora L. F. , Voogd Eva J. H. F. , Schupp Lieve M. , Collette Sabine L. , Groot Adrien E. D. , LeCouffe Natalie E. , Konduri Praneeta R. , Prasetya Haryadi , Arrarte‐Terreros Nerea , Ramos Lucas A. 
Published: December 2021

Background
Time to reperfusion in patients with ischemic stroke is strongly associated with functional outcome and may differ between hospitals and between patients within hospitals. Improvement in time to reperfusion can be guided by between‐hospital and within‐hospital comparisons and requires insight in specific targets for improvement. We aimed to quantify the variation in door‐to‐reperfusion time between and within Dutch intervention hospitals and to assess the contribution of different time intervals to this variation.

Methods and Results
We used data from the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) Registry. The door‐to‐reperfusion time was subdivided into time intervals, separately for direct patients (door‐to‐computed tomography, computed tomography‐to‐computed tomography angiography [CTA], CTA‐to‐groin, and groin‐to‐reperfusion times) and for transferred patients (door‐to‐groin and groin‐to‐reperfusion times). We used linear mixed models to distinguish the variation in door‐to‐reperfusion time between hospitals and between patients. The proportional change in variance was used to estimate the amount of variance explained by each time interval. We included 2855 patients of 17 hospitals providing endovascular treatment. Of these patients, 44% arrived directly at an endovascular treatment hospital. The between‐hospital variation in door‐to‐reperfusion time was 9%, and the within‐hospital variation was 91%. The contribution of case‐mix variables on the variation in door‐to‐reperfusion time was marginal (2%–7%). Of the between‐hospital variation, CTA‐to‐groin time explained 83%, whereas groin‐to‐reperfusion time explained 15%. Within‐hospital variation was mostly explained by CTA‐to‐groin time (33%) and groin‐to‐reperfusion time (42%). Similar results were found for transferred patients.

Conclusions
Door‐to‐reperfusion time varies between, but even more within, hospitals providing endovascular treatment for ischemic stroke. Quality of stroke care improvements should not only be guided by between‐hospital comparisons, but also aim to reduce variation between patients within a hospital, and should specifically focus on CTA‐to‐groin time and groin‐to‐reperfusion time.