Search

Abstract Background Standardized Mortality Ratios (SMRs) are case-mix adjusted mortality rates per hospital and are used to evaluate quality of care. However, acute care is increasingly organized on a regional level, with more severe patients admitted to specialized hospitals. We hypothesize that the current case-mix adjustment insufficiently captures differences in case-mix between non-specialized and specialized hospitals. We aim to improve the SMR by adding proxies of disease severity to the model and by calculating a regional SMR (RSMR) for acute cerebrovascular disease (CVD) and myocardial infarction (MI). Methods We used data from the Dutch National Basic Registration of Hospital Care. We selected all admissions from 2016 to 2018. SMRs and RSMRs were calculated by dividing the observed in-hospital mortality by the expected in-hospital mortality. The expected in-hospital mortality was calculated using logistic regression with adjustment for age, sex, socioeconomic status, severity of main diagnosis, urgency of admission, Charlson comorbidity index, place of residence before admission, month/year of admission, and in-hospital mortality as outcome. Results The IQR of hospital SMRs of CVD was 0.85–1.10, median 0.94, with higher SMRs for specialized hospitals (median 1.12, IQR 1.00-1.28, 71%-SMR > 1) than for non-specialized hospitals (median 0.92, IQR 0.82–1.07, 32%-SMR > 1). The IQR of RSMRs was 0.92–1.09, median 1.00. The IQR of hospital SMRs of MI was 0.76–1.14, median 0.98, with higher SMRs for specialized hospitals (median 1.00, IQR 0.89–1.25, 50%-SMR > 1 versus median 0.94, IQR 0.74–1.11, 44%-SMR > 1). The IQR of RSMRs was 0.90–1.08, median 1.00. Adjustment for proxies of disease severity mostly led to lower SMRs of specialized hospitals. Conclusion SMRs of acute regionally organized diseases do not only measure differences in quality of care between hospitals, but merely measure differences in case-mix between hospitals. Although the addition of proxies of disease severity improves the model to calculate SMRs, real disease severity scores would be preferred. However, such scores are not available in administrative data. As a consequence, the usefulness of the current SMR as quality indicator is very limited. RSMRs are potentially more useful, since they fit regional organization and might be a more valid representation of quality of care.

Background Insight into outcome variation between hospitals could help to improve quality of care. We aimed to assess the validity of early outcomes as quality indicators for acute ischemic stroke care for patients treated with endovascular therapy (EVT). Methods and Results We used data from the MR CLEAN (Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) Registry, a large multicenter prospective cohort study including 3279 patients with acute ischemic stroke undergoing EVT. Random effect linear and proportional odds regression were used to analyze the effect of case mix on between‐hospital differences in 2 early outcomes: the National Institutes of Health Stroke Scale (NIHSS) score at 24 to 48 hours and the expanded thrombolysis in cerebral infarction score. Between‐hospital variation in outcomes was assessed using the variance of random hospital effects (tau2). In addition, we estimated the correlation between hospitals' EVT‐patient volume and (case‐mix–adjusted) outcomes. Both early outcomes and case‐mix characteristics varied significantly across hospitals. Between‐hospital variation in the expanded thrombolysis in cerebral infarction score was not influenced by case‐mix adjustment (tau 2=0.17 in both models). In contrast, for the NIHSS score at 24 to 48 hours, case‐mix adjustment led to a decrease in variation between hospitals (tau 2 decreases from 0.19 to 0.17). Hospitals' EVT‐patient volume was strongly correlated with higher expanded thrombolysis in cerebral infarction scores (r=0.48) and weakly with lower NIHSS score at 24 to 48 hours (r=0.15). Conclusions Between‐hospital variation in NIHSS score at 24 to 48 hours is significantly influenced by case‐mix but not by patient volume. In contrast, between‐hospital variation in expanded thrombolysis in cerebral infarction score is strongly influenced by EVT‐patient volume but not by case‐mix. Both outcomes may be suitable for comparing hospitals on quality of care, provided that adequate adjustment for case‐mix is applied for NIHSS score.

Abstract Background Although the provision of performance feedback to healthcare professionals based on data from quality registries is common practice in many fields of medicine, observational studies of its effect on the quality of care have shown mixed results. The objective of this study is to evaluate the effect of performance feedback on the quality of care for acute ischemic stroke. Methods PERFEQTOS is a stepped wedge cluster randomized trial in 13 hospitals in the Netherlands providing endovascular thrombectomy for ischemic stroke. The primary outcome is the hospital’s door-to-groin time. The study starts with a 6-month period in which none of the hospitals receives the performance feedback intervention. Subsequently, every 6 months, three or four hospitals are randomized to cross over from the control to the intervention conditions, until all hospitals receive the feedback intervention. The feedback intervention consists of a dashboard with quarterly reports on patient characteristics, structure, process, and outcome indicators related to patients with ischemic stroke treated with endovascular thrombectomy. Hospitals can compare their present performance with their own performance in the past and with other hospitals. The performance feedback is provided to local quality improvement teams in each hospital, who define their own targets on specific indicators and develop performance improvement plans. The impact of the performance feedback and improvement plans will be evaluated by comparing the primary outcome before and after the intervention. Discussion This study will provide evidence on the effectiveness of performance feedback to healthcare providers. The results will be actively disseminated through peer-reviewed journals, conference presentations, and various stakeholder engagement activities. Trial registration Netherlands Trial Register NL9090 . Registered on December 3, 2020

Background It has been suggested that selection of a first‐line endovascular thrombectomy device, that is, contact aspiration (CA) or stent retriever (SR) thrombectomy, could be based on thrombus type. Thrombus composition and mechanical behavior can partially be predicted with thrombus computed tomography (CT) characteristics. We aimed to assess the influence of thrombus CT characteristics on the association between first‐line device and outcomes of endovascular thrombectomy. Methods For patients enrolled in the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in The Netherlands) Registry between March 2014 and November 2017, we assessed thrombus density, thrombus length, and presence of hyperdense artery sign on thin‐slice (≤2.5 mm) admission CT. We used regression models to estimate the relationship between first‐line endovascular thrombectomy device (CA versus stent retriever) and first‐pass reperfusion (FPR, expanded Thrombolysis in Cerebral Infarction score 2C‐3 after first attempt), final reperfusion, procedure duration, 24‐hour National Institutes of Health Stroke Scale, and 90‐day modified Rankin scale score and tested for interaction of thrombus characteristics with first‐line device by adding interaction terms. Results Of 703 included patients, 520 (74%) received first‐line stent retriever and 183 (26%) first‐line CA. Overall, the first‐line device was not associated with FPR (adjusted odds ratio [aOR], 1.32 [95% CI, 0.88–1.98]). In patients with thrombus density below the median (

Background Contrary to anterior circulation stroke, studies on the association between thrombus imaging characteristics and outcomes are scarce in patients with posterior circulation stroke (PCS). We aimed to investigate the association of thrombus imaging characteristics with reperfusion and functional outcome in patients with PCS who underwent endovascular treatment. Methods In patients with PCS included in the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in The Netherlands) Registry, thrombus imaging characteristics (thrombus density and perviousness in Hounsfield Units [HU] and thrombus length in mm) were assessed on thin‐slice imaging (

Background: A considerable proportion of acute ischemic stroke patients treated with endovascular thrombectomy (EVT) are dead or severely disabled at 3 months despite successful reperfusion. Ischemic core imaging biomarkers may help to identify patients who are more likely to have a poor outcome after endovascular thrombectomy (EVT) despite successful reperfusion. We studied the association of CT perfusion-(CTP), CT angiography-(CTA), and non-contrast CT-(NCCT) based imaging markers with poor outcome in patients who underwent EVT in daily clinical practice.Methods: We included EVT-treated patients (July 2016–November 2017) with an anterior circulation occlusion from the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN) Registry with available baseline CTP, CTA, and NCCT. We used multivariable binary and ordinal logistic regression to analyze the association of CTP ischemic core volume, CTA-Collateral Score (CTA-CS), and Alberta Stroke Program Early CT Score (ASPECTS) with poor outcome (modified Rankin Scale score (mRS) 5-6) and likelihood of having a lower score on the mRS at 90 days.Results: In 201 patients, median core volume was 13 (IQR 5-41) mL. Median ASPECTS was 9 (IQR 8-10). Most patients had grade 2 (83/201; 42%) or grade 3 (28/201; 14%) collaterals. CTP ischemic core volume was associated with poor outcome [aOR per 10 mL 1.02 (95%CI 1.01–1.04)] and lower likelihood of having a lower score on the mRS at 90 days [aOR per 10 mL 0.85 (95% CI 0.78–0.93)]. In multivariable analysis, neither CTA-CS nor ASPECTS were significantly associated with poor outcome or the likelihood of having a lower mRS.Conclusion: In our population of patients treated with EVT in daily clinical practice, CTP ischemic core volume is associated with poor outcome and lower likelihood of shift toward better outcome in contrast to either CTA-CS or ASPECTS.

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.

Background First‐pass reperfusion (FPR) is associated with favorable outcome after endovascular treatment. It is unknown whether this effect is independent of patient characteristics and whether FPR has better outcomes compared with excellent reperfusion (Expanded Thrombolysis in Cerebral Infarction [eTICI] 2C‐3) after multiple‐passes reperfusion. We aimed to evaluate the association between FPR and outcome with adjustment for patient, imaging, and treatment characteristics to single out the contribution of FPR. Methods and Results FPR was defined as eTICI 2C‐3 after 1 pass. Multivariable regression models were used to investigate characteristics associated with FPR and to investigate the effect of FPR on outcomes. We included 2686 patients of the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) Registry. Factors associated with FPR were as follows: history of hyperlipidemia (adjusted odds ratio [OR], 1.05; 95% CI, 1.01–1.10), middle cerebral artery versus intracranial carotid artery occlusion (adjusted OR, 1.11; 95% CI, 1.06–1.16), and aspiration versus stent thrombectomy (adjusted OR, 1.07; 95% CI, 1.03–1.11). Interventionist experience increased the likelihood of FPR (adjusted OR, 1.03 per 50 patients previously treated; 95% CI, 1.01–1.06). Adjusted for patient, imaging, and treatment characteristics, FPR remained associated with a better 24‐hour National Institutes of Health Stroke Scale (NIHSS) score (−37%; 95% CI, −43% to −31%) and a better modified Rankin Scale (mRS) score at 3 months (adjusted common OR, 2.16; 95% CI, 1.83–2.54) compared with no FPR (multiple‐passes reperfusion+no excellent reperfusion), and compared with multiple‐passes reperfusion alone (24‐hour NIHSS score, (−23%; 95% CI, −31% to −14%), and mRS score (adjusted common OR, 1.45; 95% CI, 1.19–1.78)). Conclusions FPR compared with multiple‐passes reperfusion is associated with favorable outcome, independently of patient, imaging, and treatment characteristics. Factors associated with FPR were the experience of the interventionist, history of hyperlipidemia, location of occluded artery, and use of an aspiration device compared with stent thrombectomy.

Thrombus volume in posterior circulation stroke (PCS) has been associated with outcome, through recanalization. Manual thrombus segmentation is impractical for large scale analysis of image characteristics. Hence, in this study we develop the first automatic method for thrombus localization and segmentation on CT in patients with PCS. In this multi-center retrospective study, 187 patients with PCS from the MR CLEAN Registry were included. We developed a convolutional neural network (CNN) that segments thrombi and restricts the volume-of-interest (VOI) to the brainstem (Polar-UNet). Furthermore, we reduced false positive localization by removing small-volume objects, referred to as volume-based removal (VBR). Polar-UNet is benchmarked against a CNN that does not restrict the VOI (BL-UNet). Performance metrics included the intra-class correlation coefficient (ICC) between automated and manually segmented thrombus volumes, the thrombus localization precision and recall, and the Dice coefficient. The majority of the thrombi were localized. Without VBR, Polar-UNet achieved a thrombus localization recall of 0.82, versus 0.78 achieved by BL-UNet. This high recall was accompanied by a low precision of 0.14 and 0.09. VBR improved precision to 0.65 and 0.56 for Polar-UNet and BL-UNet, respectively, with a small reduction in recall to 0.75 and 0.69. The Dice coefficient achieved by Polar-UNet was 0.44, versus 0.38 achieved by BL-UNet with VBR. Both methods achieved ICCs of 0.41 (95% CI: 0.27–0.54). Restricting the VOI to the brainstem improved the thrombus localization precision, recall, and segmentation overlap compared to the benchmark. VBR improved thrombus localization precision but lowered recall.

Background Randomised controlled trials with perfusion selection have shown benefit of endovascular treatment (EVT) for ischaemic stroke between 6 and 24 hours after symptom onset or time last seen well. However, outcomes after EVT in these late window patients without perfusion imaging are largely unknown. We assessed their characteristics and outcomes in routine clinical practice.Methods The Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands Registry, a prospective, multicentre study in the Netherlands, included patients with an anterior circulation occlusion who underwent EVT between 2014 and 2017. CT perfusion was no standard imaging modality. We used adjusted ordinal logistic regression analysis to compare patients treated within versus beyond 6.5 hours after propensity score matching on age, prestroke modified Rankin Scale (mRS), National Institutes of Health Stroke Scale, Alberta Stroke Programme Early CT Score (ASPECTS), collateral status, location of occlusion and treatment with intravenous thrombolysis. Outcomes included 3-month mRS score, functional independence (defined as mRS 0–2), and death.Results Of 3264 patients who underwent EVT, 106 (3.2%) were treated beyond 6.5 hours (median 8.5, IQR 6.9–10.6), of whom 93 (87.7%) had unknown time of stroke onset. CT perfusion was not performed in 87/106 (80.2%) late window patients. Late window patients were younger (mean 67 vs 70 years, p