The impact of organizational and temporal factors on acute stroke care in Sweden

Background: Acute stroke carries a high risk of morbidity and death, but early treatment can improve outcomes. Intravenous stroke thrombolysis (IVT) is one such treatment, it is however time-sensitive and show better outcomes the sooner it is given. Most studies on time to IVT so far have looked at fixed time-intervals, and studies of short delays in clinical practice are relatively scarce. Another well-established treatment is managing acute stroke patients in stroke units (SU). Admission rates to a SU as first destination of hospital care have improved over time in Sweden. In the past decade however, the rates have leveled out at around 75-80% without further improvement. A hypothesis is that in-hospital overcrowding contributes. Previous studies have shown that outcomes after stroke differ between hospital types, and also vary depending on time of admission, with higher mortality seen for off-hours, weekend and winter admissions. The reasons behind temporal variations are not fully understood, but it has been proposed that environmental, patient-related and organizational factors contribute. The overall aim of this thesis was to study the effect of organizational factors on quality of care and outcomes after stroke, primarily focusing on the role of in-hospital overcrowding, in-hospital time to IVT and time of admission, while also studying differences between hospitals. Methods: All papers in this thesis were based on data from the Swedish stroke register (Riksstroke), a national quality register that holds data on patient related factors, acute care and outcomes. Paper I included 13,955 patient admissions from 14 hospitals in Region Norrbotten and Region Skåne from 2011-2014, enriched with data on in-hospital bed occupancy. Papers II-IV included all 72 Swedish hospitals caring for patients with acute stroke. Paper II included data from 2011-2015 (N=113,862), paper III from 2011-2016 (N=132,744) and paper IV from 2010-2017 (N=14,132). Analyses included descriptive statistics, unadjusted analyses and multivariable adjusted analyses. Results: We found that each percent increase in in-hospital bed occupancy above 85% decreased admission rates to a SU as first destination of hospital care by 1.5% (odds ratio (OR) 0.985, 95% confidence interval (CI) 0.978-0.992), with significant differences between hospitals. Admission rates were also lower off-hours, compared to on-hours (OR 0.73, 95% CI 0.70-0.75). Over time, admission rates to a SU as first destination of hospital care decreased in university hospitals, while they increased in specialized non-university hospitals and community hospitals. Each minute delay in door-to-needle time (DNT) decreased the odds of 90-day survival by 0.6% (OR 0.994, 95% CI 0.992-0.996), increased the odds of ICH within 36 hours by 0.3% (OR 1.003, 95% CI 1.000-1.006), and led to significantly higher odds of a worsening in functional outcomes at 3 months by 0.3-0.4%. DNT within 30 minutes was most likely daytime, and varied between hospital types. 90-day survival was lowest for patients admitted in January (81.5%), and highest for those admitted in May (84.1%) (OR 1.28, 95% CI 1.17-1.40). Conclusion: We found that in-hospital overcrowding decrease admission rates to a SU as first destination of hospital care, and that even short delays in DNT decreases survival, increases ICH complications and leads to a worsening in functional outcomes in routine clinical practice. We also found that quality of care varied depending on time of admission and between hospitals, indicating unequal care. Organizational differences should be accessible through quality improvement efforts aiming to implement robust local guidelines for in-hospital stroke treatment

The impact of organizational and temporal factors on acute stroke care in Sweden

Background: Acute stroke carries a high risk of morbidity and death, but early treatment can improve outcomes. Intravenous stroke thrombolysis (IVT) is one such treatment, it is however time-sensitive and show better outcomes the sooner it is given. Most studies on time to IVT so far have looked at fixed time-intervals, and studies of short delays in clinical practice are relatively scarce. Another well-established treatment is managing acute stroke patients in stroke units (SU). Admission rates to a SU as first destination of hospital care have improved over time in Sweden. In the past decade however, the rates have leveled out at around 75-80% without further improvement. A hypothesis is that in-hospital overcrowding contributes. Previous studies have shown that outcomes after stroke differ between hospital types, and also vary depending on time of admission, with higher mortality seen for off-hours, weekend and winter admissions. The reasons behind temporal variations are not fully understood, but it has been proposed that environmental, patient-related and organizational factors contribute. The overall aim of this thesis was to study the effect of organizational factors on quality of care and outcomes after stroke, primarily focusing on the role of in-hospital overcrowding, in-hospital time to IVT and time of admission, while also studying differences between hospitals. Methods: All papers in this thesis were based on data from the Swedish stroke register (Riksstroke), a national quality register that holds data on patient related factors, acute care and outcomes. Paper I included 13,955 patient admissions from 14 hospitals in Region Norrbotten and Region Skåne from 2011-2014, enriched with data on in-hospital bed occupancy. Papers II-IV included all 72 Swedish hospitals caring for patients with acute stroke. Paper II included data from 2011-2015 (N=113,862), paper III from 2011-2016 (N=132,744) and paper IV from 2010-2017 (N=14,132). Analyses included descriptive statistics, unadjusted analyses and multivariable adjusted analyses. Results: We found that each percent increase in in-hospital bed occupancy above 85% decreased admission rates to a SU as first destination of hospital care by 1.5% (odds ratio (OR) 0.985, 95% confidence interval (CI) 0.978-0.992), with significant differences between hospitals. Admission rates were also lower off-hours, compared to on-hours (OR 0.73, 95% CI 0.70-0.75). Over time, admission rates to a SU as first destination of hospital care decreased in university hospitals, while they increased in specialized non-university hospitals and community hospitals. Each minute delay in door-to-needle time (DNT) decreased the odds of 90-day survival by 0.6% (OR 0.994, 95% CI 0.992-0.996), increased the odds of ICH within 36 hours by 0.3% (OR 1.003, 95% CI 1.000-1.006), and led to significantly higher odds of a worsening in functional outcomes at 3 months by 0.3-0.4%. DNT within 30 minutes was most likely daytime, and varied between hospital types. 90-day survival was lowest for patients admitted in January (81.5%), and highest for those admitted in May (84.1%) (OR 1.28, 95% CI 1.17-1.40). Conclusion: We found that in-hospital overcrowding decrease admission rates to a SU as first destination of hospital care, and that even short delays in DNT decreases survival, increases ICH complications and leads to a worsening in functional outcomes in routine clinical practice. We also found that quality of care varied depending on time of admission and between hospitals, indicating unequal care. Organizational differences should be accessible through quality improvement efforts aiming to implement robust local guidelines for in-hospital stroke treatment

The impact of organizational and temporal factors on acute stroke care in Sweden

Background: Acute stroke carries a high risk of morbidity and death, but early treatment can improve outcomes. Intravenous stroke thrombolysis (IVT) is one such treatment, it is however time-sensitive and show better outcomes the sooner it is given. Most studies on time to IVT so far have looked at fixed time-intervals, and studies of short delays in clinical practice are relatively scarce. Another well-established treatment is managing acute stroke patients in stroke units (SU). Admission rates to a SU as first destination of hospital care have improved over time in Sweden. In the past decade however, the rates have leveled out at around 75-80% without further improvement. A hypothesis is that in-hospital overcrowding contributes. Previous studies have shown that outcomes after stroke differ between hospital types, and also vary depending on time of admission, with higher mortality seen for off-hours, weekend and winter admissions. The reasons behind temporal variations are not fully understood, but it has been proposed that environmental, patient-related and organizational factors contribute. The overall aim of this thesis was to study the effect of organizational factors on quality of care and outcomes after stroke, primarily focusing on the role of in-hospital overcrowding, in-hospital time to IVT and time of admission, while also studying differences between hospitals. Methods: All papers in this thesis were based on data from the Swedish stroke register (Riksstroke), a national quality register that holds data on patient related factors, acute care and outcomes. Paper I included 13,955 patient admissions from 14 hospitals in Region Norrbotten and Region Skåne from 2011-2014, enriched with data on in-hospital bed occupancy. Papers II-IV included all 72 Swedish hospitals caring for patients with acute stroke. Paper II included data from 2011-2015 (N=113,862), paper III from 2011-2016 (N=132,744) and paper IV from 2010-2017 (N=14,132). Analyses included descriptive statistics, unadjusted analyses and multivariable adjusted analyses. Results: We found that each percent increase in in-hospital bed occupancy above 85% decreased admission rates to a SU as first destination of hospital care by 1.5% (odds ratio (OR) 0.985, 95% confidence interval (CI) 0.978-0.992), with significant differences between hospitals. Admission rates were also lower off-hours, compared to on-hours (OR 0.73, 95% CI 0.70-0.75). Over time, admission rates to a SU as first destination of hospital care decreased in university hospitals, while they increased in specialized non-university hospitals and community hospitals. Each minute delay in door-to-needle time (DNT) decreased the odds of 90-day survival by 0.6% (OR 0.994, 95% CI 0.992-0.996), increased the odds of ICH within 36 hours by 0.3% (OR 1.003, 95% CI 1.000-1.006), and led to significantly higher odds of a worsening in functional outcomes at 3 months by 0.3-0.4%. DNT within 30 minutes was most likely daytime, and varied between hospital types. 90-day survival was lowest for patients admitted in January (81.5%), and highest for those admitted in May (84.1%) (OR 1.28, 95% CI 1.17-1.40). Conclusion: We found that in-hospital overcrowding decrease admission rates to a SU as first destination of hospital care, and that even short delays in DNT decreases survival, increases ICH complications and leads to a worsening in functional outcomes in routine clinical practice. We also found that quality of care varied depending on time of admission and between hospitals, indicating unequal care. Organizational differences should be accessible through quality improvement efforts aiming to implement robust local guidelines for in-hospital stroke treatment

Mediation analyses of the mechanisms by which socioeconomic status, comorbidity, stroke severity, and acute care influence stroke outcome

BACKGROUND AND OBJECTIVES: Low socioeconomic status (SES) is associated with increased risk of death and disability after stroke, but interventional targets to minimize disparities remain unclear. We aim to assess the extent to which SES-based disparities in the association between low SES and death and dependency at three months after stroke could be eliminated by offsetting differences in comorbidity, stroke severity, and acute care. METHODS: This nationwide register-based cohort study included all 72 hospitals caring for patients with acute stroke in Sweden. All patients registered with an acute ischemic stroke in the Swedish Stroke Register in 2015-2016 who were independent in activities of daily living (ADL) at the time of stroke were included. Data on survival and SES the year before stroke were retrieved by cross-linkage with other national registers. SES was defined by education and income, and categorized into low, mid, and high. Causal mediation analysis was used to study the absolute risk of death and ADL-dependency at 3 months depending on SES, and to what extent hypothetical interventions on comorbidities, stroke severity, and acute care would equalize outcomes. RESULTS: Of the 25,846 patients in the study, 6,798 (26.3%) were dead or ADL-dependent three months after stroke. Adjusted for sex and age, low SES was associated with an increased absolute risk of 5.4% (95% CI: 3.9%-6.9%; p<0.001) compared to mid SES, and 10.1% (95% CI: 8.1%-12.2%; p<0.001) compared to high SES. Intervening to shift the distribution of all mediators among patients with low SES to those of the more privileged groups would result in absolute reductions of these effects by 2.2% (95% CI: 1.2%-3.2%; p<0.001), and 4.0% (95% CI: 2.6%-5.5%; p<0.001), respectively, with the largest reduction accomplished by equalizing stroke severity. DISCUSSION: Low SES patients have substantially increased risks of death and ADL-dependency three months after stroke compared to more privileged patient groups. This study suggests that if we could intervene to equalize SES-related differences in the distributions of comorbidity, acute care, and stroke severity, up to 40 out of every 1000 patients with low SES could be prevented from dying or becoming ADL-dependent

Socioeconomic status and stroke severity : Understanding indirect effects via risk factors and stroke prevention using innovative statistical methods for mediation analysis

Background: Those with low socioeconomic status have an increased risk of stroke, more severe strokes, reduced access to treatment, and more adverse outcomes after stroke. The question is why these differences are present. In this study we investigate to which extent the association between low socioeconomic status and stroke severity can be explained by differences in risk factors and stroke prevention drugs. Methods: The study included 86 316 patients registered with an ischemic stroke in the Swedish Stroke Register (Riksstroke) 2012–2016. Data on socioeconomic status was retrieved from the Longitudinal integrated database for health insurance and labour market studies (LISA) by individual linkage. We used education level as proxy for socioeconomic status, with primary school education classified as low education. Stroke severity was measured using the Reaction Level Scale, with values above 1 classified as severe strokes. To investigate the pathways via risk factors and stroke prevention drugs we performed a mediation analysis estimating indirect and direct effects. Results: Low education was associated with an excess risk of a severe stroke compared to mid/high education (absolute risk difference 1.4%, 95% CI: 1.0%-1.8%), adjusting for confounders. Of this association 28.5% was an indirect effect via risk factors (absolute risk difference 0.4%, 95% CI: 0.3%-0.5%), while the indirect effect via stroke prevention drugs was negligible. Conclusion: Almost one third of the association between low education and severe stroke was explained by risk factors, and clinical effort should be taken to reduce these risk factors to decrease stroke severity among those with low socioeconomic status

Developing machine learning models to predict multi-class functional outcomes and death three months after stroke in Sweden

Globally, stroke is the third-leading cause of mortality and disability combined, and one of the costliest diseases in society. More accurate predictions of stroke outcomes can guide healthcare organizations in allocating appropriate resources to improve care and reduce both the economic and social burden of the disease. We aim to develop and evaluate the performance and explainability of three supervised machine learning models and the traditional multinomial logistic regression (mLR) in predicting functional dependence and death three months after stroke, using routinely-collected data. This prognostic study included adult patients, registered in the Swedish Stroke Registry (Riksstroke) from 2015 to 2020. Riksstroke contains information on stroke care and outcomes among patients treated in hospitals in Sweden. Prognostic factors (features) included demographic characteristics, pre-stroke functional status, cardiovascular risk factors, medications, acute care, stroke type, and severity. The outcome was measured using the modified Rankin Scale at three months after stroke (a scale of 0-2 indicates independent, 3-5 dependent, and 6 dead). Outcome prediction models included support vector machines, artificial neural networks (ANN), eXtreme Gradient Boosting (XGBoost), and mLR. The models were trained and evaluated on 75% and 25% of the dataset, respectively. Model predictions were explained using SHAP values. The study included 102,135 patients (85.8% ischemic stroke, 53.3% male, mean age 75.8 years, and median NIHSS of 3). All models demonstrated similar overall accuracy (69%-70%). The ANN and XGBoost models performed significantly better than the mLR in classifying dependence with F1-scores of 0.603 (95% CI; 0.594-0.611) and 0.577 (95% CI; 0.568-0.586), versus 0.544 (95% CI; 0.545-0.563) for the mLR model. The factors that contributed most to the predictions were expectedly similar in the models, based on clinical knowledge. Our ANN and XGBoost models showed a modest improvement in prediction performance and explainability compared to mLR using routinely-collected data. Their improved ability to predict functional dependence may be of particular importance for the planning and organization of acute stroke care and rehabilitation

Mortality and complications after percutaneous endoscopic gastrostomy : a retrospective multicentre study

Background: Percutaneous endoscopic gastrostomy (PEG) is the method of choice for patients in need of long-term nutritional support or gastric decompression. Although it is considered safe, complications and relatively high mortality rates have been reported. We aimed to identify risk factors for complications and mortality after PEG in routine healthcare. Methods: This retrospective study included all adult patients who received a PEG between 2013 and 2019 in Region Norrbotten, Sweden. Results: 389 patients were included. The median age was 72 years, 176 (45%) were women and 281 (72%) patients received their PEG due to neurological disease. All-cause mortality was 15% at 30 days and 28% at 90 days. Malignancy as the indication for PEG was associated with increased mortality at 90 days (OR 4.41, 95% CI 2.20–8.88). Other factors significantly associated with increased mortality were older age, female sex, diabetes mellitus, heart failure, lower body mass index and higher C-reactive protein levels. Minor and major complications within 30 days occurred in 11% and 15% of the patients, respectively. Diabetes increased the risk of minor complications (OR 2.61, 95% CI 1.04–6.55), while those aged 75 + years were at an increased risk of major complications, compared to those younger than 65 years (OR 2.23, 95% CI 1.02–4.85). Conclusions: The increased risk of death among women and patients with malignancy indicate that these patients could benefit from earlier referral for PEG. Additionally, we found that age, diabetes, heart failure, C-reactive protein and body mass index all impact the risk of adverse outcomes

Patients with acute stroke are less likely to be admitted directly to a stroke unit when hospital beds are scarce : A Swedish multicenter register study

Introduction: It is well established that managing patients with acute stroke in dedicated stroke units is associated with improved functioning and survival. The objectives of this study are to investigate whether patients with acute stroke are less likely to be directly admitted to a stroke unit from the Emergency Department when hospital beds are scarce and to measure variation across hospitals in terms of this outcome. Patients and methods: This register study comprised data on patients with acute stroke admitted to 14 out of 72 Swedish hospitals in 2011–2014. Data from the Swedish stroke register were linked to administrative daily data on hospital bed occupancy (measured at 6 a.m.). Logistic regression analysis was used to analyse the association between bed occupancy and direct stroke unit admission. Results: A total of 13,955 hospital admissions were included; 79.6% were directly admitted to a stroke unit from the Emergency Department. Each percentage increase in hospital bed occupancy was associated with a 1.5% decrease in odds of direct admission to a stroke unit (odds ratio = 0.985, 95% confidence interval = 0.978–0.992). The best-performing hospital exhibited an odds ratio of 3.8 (95% confidence interval = 2.6–5.5) for direct admission to a stroke unit versus the reference hospital. Discussion and conclusion: We found an association between hospital crowding and reduced quality of care in acute stroke, portrayed by a lower likelihood of patients being directly admitted to a stroke unit from the Emergency Department. The magnitude of the effect varied considerably across hospitals

Characteristics of in-hospital stroke patients in Sweden : a nationwide register-based study

INTRODUCTION: Few studies have reported the characteristics of patients with in-hospital stroke (IHS) including the reason for hospitalization and invasive procedures before the stroke. We aimed to extend current knowledge. PATIENTS AND METHODS: All adult patients with IHS in Sweden during 2010-2019 registered in the Swedish Stroke Register (Riksstroke) were included. The cohort was cross-linked to the National Patient Register and data extracted on background diagnoses, main discharge diagnoses, and procedure codes for the hospitalization when IHS occurred and any hospital-based healthcare contacts within 30 days before IHS. RESULTS: 231,402 stroke cases were identified of which 12,551 (5.4%) were in-hospital and had corresponding entries in the National Patient Register. Of the IHS patients, 11,420 (91.0%) had ischemic stroke and 1131 (9.0%) hemorrhagic stroke; 5860 (46.7%) of the IHS patients had at least one invasive procedure prior to ictus. 1696 (13.5%) had a cardiovascular procedure and 560 (4.5%) a neurosurgical procedure. 1319 (10.5%) patients only had minimally invasive procedures such as blood product transfusion, hemodialysis, or central line insertion. Common discharge diagnosis in patients with no invasive procedures were cardiovascular disorders, injuries, and respiratory disorders. DISCUSSION AND CONCLUSION: One in every 17 strokes in Sweden occur in a hospital. In this unselected large cohort the previously reported major causes for in-hospital stroke, cardiovascular and neurosurgical procedures, preceded IHS in only 18.0% of cases suggesting that other etiologies are more common than previously reported. Future studies should aim at determining absolute risks of stroke after surgical procedures and ways of risk reduction

In-Hospital Delays in Stroke Thrombolysis : Every Minute Counts

BACKGROUND AND PURPOSE: Intravenous thrombolysis is a well-established treatment for acute ischemic stroke. Our aim was to quantify the effect of each minute delay in door-to-needle time (DNT) on 90-day survival, intracerebral hemorrhagic complication <36 hours, and functional outcomes at 3 months, in routine clinical practice. METHODS: Our nationwide registry-based study included 14 132 adult patient admissions with ischemic stroke receiving intravenous thrombolysis from 2010 to 2017. Outcomes were analyzed using multivariable logistic regression, adjusting for potential confounders. RESULTS: Median DNT was 47 minutes, with an improvement from 65 to 38 minutes during the study. Median age was 74 years, and median National Institutes of Health Stroke Scale 8 points. We found a significant impact of each minute delay in DNT with reduced odds of survival by 0.6%, increased odds of intracerebral hemorrhagic and worse activities of daily living by 0.3%, and worse living conditions and mobility by 0.4%. CONCLUSIONS: Improving DNT is a key factor in achieving good outcomes after stroke. We estimate that in Sweden alone in 2017, compared with 2010, the shorter DNT achieved have saved 38 lives, avoided 8 intracerebral hemorrhagic transformations, and spared, respectively, 36, 51, and 52 patients from a worsening in activities of daily living, living conditions, and mobility. DNT is sensitive for interventions and should be targeted in quality improvement efforts