Non-ABO red cell antibodies and risk of COVID-19.

It is not known whether non-ABO antibodies confer any protective effect against SARS-CoV-2 infection or COVID-19 severe illness alone or in conjunction with O blood group. This cohort study included 413 576 persons in Ontario, Canada with known ABO blood group and non-ABO antibody screen status, who subsequently underwent SARS-CoV-2 viral RNA polymerase chain reaction testing between January and November 2020. The risk of SARS-CoV-2 infection or COVID-19 severe illness was not associated with the presence of non-ABO antibodies, even among persons with O blood group.

Association Between ABO and Rh Blood Groups and SARS-CoV-2 Infection or Severe COVID-19 Illness : A Population-Based Cohort Study.

BACKGROUND: The ABO and rhesus (Rh) blood groups may influence risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. OBJECTIVE: To determine whether ABO and Rh blood groups are associated with risk for SARS-CoV-2 infection and severe coronavirus disease 2019 (COVID-19) illness. DESIGN: Population-based cohort study. SETTING: Ontario, Canada. PATIENTS: All adults and children who had ABO blood group assessed between January 2007 and December 2019 and who subsequently had SARS-CoV-2 testing between 15 January and 30 June 2020. MEASUREMENTS: The main study outcome was SARS-CoV-2 infection, determined by viral RNA polymerase chain reaction testing. A second outcome was severe COVID-19 illness or death. Adjusted relative risks (aRRs) and absolute risk differences (ARDs) were adjusted for demographic characteristics and comorbidities. RESULTS: A total of 225 556 persons were included, with a mean age of 54 years. The aRR of SARS-CoV-2 infection for O blood group versus A, AB, and B blood groups together was 0.88 (95% CI, 0.84 to 0.92; ARD, -3.9 per 1000 [CI, -5.4 to -2.5]). Rhesus-negative (Rh-) blood type was protective against SARS-CoV-2 infection (aRR, 0.79 [CI, 0.73 to 0.85]; ARD, -6.8 per 1000 [CI, -8.9 to -4.7]), especially for those who were O-negative (O-) (aRR, 0.74 [CI, 0.66 to 0.83]; ARD, -8.2 per 1000 [CI, -10.8 to -5.3]). There was also a lower risk for severe COVID-19 illness or death associated with type O blood group versus all others (aRR, 0.87 [CI, 0.78 to 0.97]; ARD, -0.8 per 1000 [CI, -1.4 to -0.2]) and with Rh- versus Rh-positive (aRR, 0.82 [CI, 0.68 to 0.96]; ARD, -1.1 per 1000 [CI, -2.0 to -0.2]). LIMITATION: Persons who rapidly died of severe COVID-19 illness may not have had SARS-CoV-2 testing. CONCLUSION: The O and Rh- blood groups may be associated with a slightly lower risk for SARS-CoV-2 infection and severe COVID-19 illness. PRIMARY FUNDING SOURCE: Ontario Academic Health Sciences Centre AFP Innovation Fund and the Ontario Ministry of Health and Long-Term Care.

Trajectories of health system use and survival for community-dwelling persons with dementia: a cohort study.

OBJECTIVES: To determine the long-term trajectories of health system use by persons with dementia as they remain in the community over time. DESIGN: Population-based cohort study using health administrative data. SETTING: Ontario, Canada from 1 April 2007 to 31 March 2014. PARTICIPANTS: 62 622 community-dwelling adults aged 65+ years with prevalent dementia on 1 April 2007 matched 1:1 to persons without dementia based on age, sex and comorbidity. MAIN OUTCOME MEASURES: Rates of health service use, long-term care placement and mortality over time. RESULTS: After 7 years, 49.0% of persons with dementia had spent time in long-term care (6.8% without) and 64.5% had died (30.0% without). Persons with dementia were more likely than those without to use home care (rate ratio (RR) 3.02, 95% CI 2.93 to 3.11) and experience hospitalisations with a discharge delay (RR 2.36, 95% CI 2.30 to 2.42). As they remained in the community, persons with dementia used home care at a growing rate (10.7%, 95% CI 10.0 to 11.3 increase per year vs 6.7%, 95% CI 4.3 to 9.0 per year among those without), but rates of acute care hospitalisation remained constant (0.6%, 95% CI -0.6 to 1.9 increase per year). CONCLUSIONS: While persons with dementia used more health services than those without dementia over time, the rate of change in use differed by service type. These results, particularly enumerating the increased intensity of home care service use, add value to capacity planning initiatives where limited budgets require balancing services.

Pivoting data and analytic capacity to support Ontario's COVID-19 response.

Introduction: Health care systems have faced unprecedented challenges due to the COVID-19 pandemic. Access to timely population-based data has been vital to informing public health policy and practice. Methods: We describe how ICES, an independent not-for-profit research and analytic institute in Ontario, Canada, pivoted existing research infrastructure and engaged health system stakeholders to provide near real-time population-based data and analytics to support Ontario's COVID-19 pandemic response. Results: Since April 2020, ICES provided the Ontario COVID-19 Provincial Command Table and public health partners with regular and ad hoc reports on SARS-CoV-2 testing and COVID-19 vaccine coverage. These reports: 1) helped identify congregate care/shared living settings that needed testing and prevention efforts early in the pandemic; 2) provided early indications of inequities in testing and infection in marginalized neighbourhoods, including areas with higher proportions of immigrants and visible minorities; 3) identified areas with high test positivity, which helped Public Health Units target and evaluate prevention efforts; and 4) contributed to altering the province's COVID-19 vaccine roll-out strategy to target high-risk neighbourhoods and helping Public Health Units and community organizations plan local vaccination programs. In addition, ICES is a key component of the Ontario Health Data Platform, which provides scientists with data access to conduct COVID-19 research and analyses. Discussion and Conclusion: ICES was well-positioned to provide rapid analyses for decision-makers to respond to the evolving public health emergency, and continues to contribute to Ontario's pandemic response by providing timely, relevant reports to health system stakeholders and facilitating data access for externally-funded COVID-19 research.

Association Between MRI Exposure During Pregnancy and Fetal and Childhood Outcomes.

IMPORTANCE: Fetal safety of magnetic resonance imaging (MRI) during the first trimester of pregnancy or with gadolinium enhancement at any time of pregnancy is unknown. OBJECTIVE: To evaluate the long-term safety after exposure to MRI in the first trimester of pregnancy or to gadolinium at any time during pregnancy. DESIGN, SETTING, AND PARTICIPANTS: Universal health care databases in the province of Ontario, Canada, were used to identify all births of more than 20 weeks, from 2003-2015. EXPOSURES: Magnetic resonance imaging exposure in the first trimester of pregnancy, or gadolinium MRI exposure at any time in pregnancy. MAIN OUTCOMES AND MEASURES: For first-trimester MRI exposure, the risk of stillbirth or neonatal death within 28 days of birth and any congenital anomaly, neoplasm, and hearing or vision loss was evaluated from birth to age 4 years. For gadolinium-enhanced MRI in pregnancy, connective tissue or skin disease resembling nephrogenic systemic fibrosis (NSF-like) and a broader set of rheumatological, inflammatory, or infiltrative skin conditions from birth were identified. RESULTS: Of 1 424 105 deliveries (48% girls; mean gestational age, 39 weeks), the overall rate of MRI was 3.97 per 1000 pregnancies. Comparing first-trimester MRI (n = 1737) to no MRI (n = 1 418 451), there were 19 stillbirths or deaths vs 9844 in the unexposed cohort (adjusted relative risk [RR], 1.68; 95% CI, 0.97 to 2.90) for an adjusted risk difference of 4.7 per 1000 person-years (95% CI, -1.6 to 11.0). The risk was also not significantly higher for congenital anomalies, neoplasm, or vision or hearing loss. Comparing gadolinium MRI (n = 397) with no MRI (n = 1 418 451), the hazard ratio for NSF-like outcomes was not statistically significant. The broader outcome of any rheumatological, inflammatory, or infiltrative skin condition occurred in 123 vs 384 180 births (adjusted HR, 1.36; 95% CI, 1.09 to 1.69) for an adjusted risk difference of 45.3 per 1000 person-years (95% CI, 11.3 to 86.8). Stillbirths and neonatal deaths occurred among 7 MRI-exposed vs 9844 unexposed pregnancies (adjusted RR, 3.70; 95% CI, 1.55 to 8.85) for an adjusted risk difference of 47.5 per 1000 pregnancies (95% CI, 9.7 to 138.2). CONCLUSIONS AND RELEVANCE: Exposure to MRI during the first trimester of pregnancy compared with nonexposure was not associated with increased risk of harm to the fetus or in early childhood. Gadolinium MRI at any time during pregnancy was associated with an increased risk of a broad set of rheumatological, inflammatory, or infiltrative skin conditions and for stillbirth or neonatal death. The study may not have been able to detect rare adverse outcomes.

Increasing Access to Health Administrative Data with ICES Data & Analytic Services.

The Institute for Clinical Evaluative Sciences (ICES) is one of only a few organizations in Ontario permitted to access, link and analyze health administrative data for the purpose of generating evidence to inform decisions in policy and practice. Although ICES is a leading research institute, its access to the data has historically been restricted to scientists with an ICES affiliation. This requirement, designed to meet ICES' data privacy and security obligations, created barriers with respect to the widespread use of Ontario's data assets. In 2014, as part of the government's commitment to the Strategy for Patient-Oriented Research, ICES launched the Data & Analytic Services platform, which is aimed at increasing access to data and analytic services to investigators external to ICES. In making the data widely available to the broader research community, this initiative engages investigators involved in front-line care, stimulates new avenues of research and fosters collaboration that was previously challenging or unfeasible.

Maternal Origin and Risk of Neonatal and Maternal ICU Admission.

OBJECTIVES: To evaluate maternal world region of birth, as well as maternal country of origin, and the associated risk of admission of 1) a mother to a maternal ICU, 2) her infant to a neonatal ICU, or 3) both concurrently to an ICU. DESIGN: Retrospective population-based cohort study. SETTING: Entire province of Ontario, Canada, from 2003 to 2012. PATIENTS: All singleton maternal-child pairs who delivered in any Ontario hospital. MEASUREMENTS AND MAIN RESULTS: We explored how maternal world region of birth, and specifically, maternal country of birth for the top 25 countries, was associated with the outcome of 1) neonatal ICU, 2) maternal ICU, and 3) both mother and newborn concurrently admitted to ICU. Relative risks were adjusted for maternal age, parity, income quintile, chronic hypertension, diabetes mellitus, obesity, dyslipidemia, drug dependence or tobacco use, and renal disease. Compared with infants of Canadian-born mothers (110.7/1,000), the rate of neonatal ICU admission was higher in immigrants from South Asia (155.2/1,000), Africa (140.4/1,000), and the Caribbean (167.3/1,000; adjusted relative risk, 1.41; 95% CI, 1.36-1.46). For maternal ICU, the adjusted relative risk was 1.79 (95% CI, 1.43-2.24) for women from Africa and 2.21 (95% CI, 1.78-2.75) for women from the Caribbean. Specifically, mothers from Ghana (adjusted relative risk, 2.71; 95% CI, 1.75-4.21) and Jamaica (adjusted relative risk, 2.74; 95% CI, 2.12-3.53) were at highest risk of maternal ICU admission. The risk of both mother and newborn concurrently admitted to ICU was even more pronounced for Ghana and Jamaica. CONCLUSIONS: Women from Africa and the Caribbean and, in particular, Ghana and Jamaica, are at higher risk of admission to ICU around the time of delivery, as are their newborns.

Prognosis after maternal placental events and revascularization: PAMPER study.

BACKGROUND: Middle-aged women are at higher risk than men of death after coronary artery revascularization. Maternal placental syndromes (gestational hypertension, preeclampsia, placental abruption, and placental infarction) are associated with premature coronary artery disease, but their influence on survival after coronary artery revascularization is unknown. OBJECTIVE: The purpose of this study was to determine whether a history of maternal placental syndromes alters the risk of death after coronary artery revascularization in middle-aged women. STUDY DESIGN: We completed a population-based retrospective cohort study among all hospitals in Ontario, Canada, where universal health care includes all aspects of antenatal and delivery care as well as all outpatient and inpatient health care, which includes coronary revascularization. We included 1985 middle-aged women who underwent a first percutaneous coronary intervention or coronary artery bypass grafting between 1993 and 2012 and who had ≥1 previous delivery. We excluded those with cardiovascular disease ≤1 year before or coronary revascularization ≤90 days after any delivery. The main study outcome, determined a priori, was all-cause death. Hazard ratios were adjusted for age, socioeconomic status, parity, revascularization type, time since last delivery, hypertension, diabetes mellitus, obesity, dyslipidemia, tobacco or drug dependence, and kidney disease. RESULTS: Three hundred sixty-two of 1985 women (18.2%) who underwent coronary artery revascularization had a previous maternal placental syndrome event. The mean age at index coronary revascularization was 45 years; percutaneous coronary intervention comprised approximately 80% of procedures. After a mean follow-up time of approximately 5 years, 41 deaths (2.2 per 100 person-years) occurred in women with previous maternal placental syndromes and 83 deaths (1.1 per 100 person-years) in women without maternal placental syndrome (adjusted hazard ratio, 1.96; 95% confidence interval, 1.29-2.99). Of the maternal placental syndrome subtypes, the risk of death was significant in women with placental abruption (adjusted hazard ratio, 2.79; 95% confidence interval, 1.31-5.96), placental infarction (adjusted hazard ratio, 3.09; 95% confidence interval, 1.23-7.74), and preeclampsia (adjusted hazard ratio, 1.61; 95% confidence interval, 1.00-2.58). Women with maternal placental syndrome in ≥2 pregnancies had the highest adjusted hazard ratio of death (4.31; 95% confidence interval, 1.71-10.89). CONCLUSION: In middle-aged women who undergo coronary revascularization, previous maternal placental syndrome doubles the risk of death; recurrent maternal placental syndrome quadruples that risk. Some covariates and secondary measures may not have been well-captured and classified herein, leading to residual confounding.

The Effect of Pay for Performance in the Emergency Department on Patient Waiting Times and Quality of Care in Ontario, Canada: A Difference-in-Differences Analysis.

STUDY OBJECTIVE: In 2008, a pay-for-performance program was implemented in sequential waves in Ontario emergency departments (EDs), with the aim of reducing length of stay. We seek to evaluate its effects on ED length of stay and quality of care. METHODS: This was a retrospective observational study of ED visits in Ontario from April 1, 2007, to March 31, 2011, using multivariable difference-in-differences analysis. Pay-for-performance hospitals and matched control sites were selected for each of 3 waves of the program. The primary outcome was 90th percentile ED length of stay; we also examined quality-of-care indicators. RESULTS: Pay-for-performance hospitals had a modest reduction in overall adjusted 90th percentile ED length of stay in wave 1 (-36 minutes; 95% confidence interval [CI] -50 to -21 minutes), but not in wave 2 (-14 minutes; 95% CI -30 to 2 minutes) or wave 3 (-7 minutes; 95% CI -23 to 8 minutes). ED admitted patients had a pronounced reduction in adjusted 90th percentile length of stay in wave 1 (-225 minutes; 95% CI -263 to -188 minutes) and wave 2 (-133 minutes; 95% CI -175 to -91 minutes). Nonadmitted low-acuity patients had reductions in adjusted 90th percentile ED length of stay in wave 1 (-24 minutes; 95% CI -29 to -18 minutes) and wave 3 (-19 minutes; 95% CI -24 to -14 minutes). The program did not negatively affect ED quality-of-care measures, such as 30-day mortality or readmission rates. CONCLUSION: Pay-for-performance was associated with modest overall benefits for ED length of stay without adversely affecting quality of care.

Are reductions in emergency department length of stay associated with improvements in quality of care? A difference-in-differences analysis.

BACKGROUND: We sought to determine whether patients seen in hospitals who had reduced overall emergency department (ED) length of stay (LOS) in the 2 years following the introduction of the Ontario Emergency Room Wait Time Strategy were more likely to experience improvements in other measures of ED quality of care for three important conditions. METHODS: Retrospective medical record review using difference-in-differences analysis to compare changes in performance on quality indicators over the 3-year period between 11 Ontario hospitals where the median ED LOS had improved from fiscal year 2008 to 2010 and 13 matched sites where ED LOS was unchanged or worsened. Patients with acute myocardial infarction (AMI), asthma and paediatric and adult upper limb fractures in these hospitals in 2008 and 2010 were evaluated with respect to 18 quality indicators reflecting timeliness and safety/effectiveness of care in the ED. In a secondary analysis, we examined shift-level ED crowding at the time of the patient visit and performance on the quality indicators. RESULTS: Median ED LOS improved by up to 26% (63 min) from 2008 to 2010 in the improved hospitals, and worsened by up to 47% (91 min) in the unimproved sites. We abstracted 4319 and 4498 charts from improved and unimproved hospitals, respectively. Improvement in a hospital's overall median ED LOS from 2008 to 2010 was not associated with a change in any of the other ED quality indicators over the same time period. In our secondary analysis, shift-level crowding was associated only with indicators that reflected timeliness of care. During less crowded shifts, patients with AMI were more likely to be reperfused within target intervals (rate ratio 1.59, 95% CI 1.03 to 2.45), patients with asthma more often received timely administration of steroids (rate ratio 1.88, 95% CI 1.59 to 2.24) and beta-agonists (rate ratio 1.47, 95% CI 1.25 to 1.74), and adult (but not paediatric) patients with fracture were more likely to receive analgesia or splinting within an hour (rate ratio 1.66, 95% CI 1.22 to 2.26). CONCLUSIONS: These results suggest that a policy approach that targets only reductions in ED LOS is not associated with broader improvements in selected quality measures. At the same time, there is no evidence that efforts to address crowding have a detrimental effect on quality of care.

The Association Between Emergency Department Crowding and the Disposition of Patients With Transient Ischemic Attack or Minor Stroke.

BACKGROUND: Emergency department (ED) crowding has been associated with adverse events, including short-term death and hospitalization among discharged patients. The mechanisms are poorly understood, but may include altered physician decision-making about ED discharge of higher-risk patients. One example is patients with transient ischemic attack (TIA) and minor stroke, who are at high risk of subsequent stroke. While hospitalization is frequently recommended, little consensus exists on which patients require admission. OBJECTIVES: The authors sought to determine the association of ED crowding with the disposition of patients with minor stroke or TIA. METHODS: This was a retrospective cohort study of prospectively collected data from the Registry of the Canadian Stroke Network at 12 EDs in Ontario, Canada, between 2003 and 2008, linked to administrative health databases. A hierarchical logistic regression model was used to determine the association between crowding at the time the patient was seen in the ED (defined as mean ED length of stay) and patient disposition (admission/discharge), after adjusting for patient and hospital-level variables. RESULTS: The study cohort included 9,759 patients (4,607 with TIA and 5,152 with minor stroke); 49.5% were discharged from the ED. The mean (±SD) age of study patients was 70.78 (±13.40) years, with 52.9% being male, 37.3% arriving by emergency medical services, and 92.3% triaged as emergent or urgent. Greater severity of ED crowding was associated with a lower likelihood of discharge, regardless of ED size. CONCLUSIONS: These results suggest that crowding may influence clinical decision-making in the disposition of patients with TIA or minor stroke and that, as crowding worsens, the likelihood of hospitalization increases.

Ontario's emergency department process improvement program: the experience of implementation.

OBJECTIVES: In recent years, Lean manufacturing principles have been applied to health care quality improvement efforts to improve wait times. In Ontario, an emergency department (ED) process improvement program based on Lean principles was introduced by the Ministry of Health and Long-Term Care as part of a strategy to reduce ED length of stay (LOS) and to improve patient flow. This article aims to describe the hospital-based teams' experiences during the ED process improvement program implementation and the teams' perceptions of the key factors that influenced the program's success or failure. METHODS: A qualitative evaluation was conducted based on semistructured interviews with hospital implementation team members, such as team leads, medical leads, and executive sponsors, at 10 purposively selected hospitals in Ontario, Canada. Sites were selected based, in part, on their changes in median ED LOS following the implementation period. A thematic framework approach as used for interviews, and a standard thematic coding framework was developed. RESULTS: Twenty-four interviews were coded and analyzed. The results are organized according to participants' experience and are grouped into four themes that were identified as significantly affecting the implementation experience: local contextual factors, relationship between improvement team and support players, staff engagement, and success and sustainability. The results demonstrate the importance of the context of implementation, establishing strong relationships and communication strategies, and preparing for implementation and sustainability prior to the start of the project. CONCLUSIONS: Several key factors were identified as important to the success of the program, such as preparing for implementation, ensuring strong executive support, creation of implementation teams based on the tasks and outcomes of the initiative, and using multiple communication strategies throughout the implementation process. Explicit incorporation of these factors into the development and implementation of future similar interventions in health care settings could be useful.

Repeated emergency department visits among children admitted with meningitis or septicemia: a population-based study.

STUDY OBJECTIVE: Early diagnosis of children with meningitis or septicemia remains a significant challenge in emergency medicine. We seek to describe the frequency of repeated emergency department (ED) visits among children admitted with meningitis or septicemia in Ontario, Canada. METHODS: In this retrospective cohort study, using health administrative data, we included all children aged 30 days to 5 years who were hospitalized with a final diagnosis of meningitis or septicemia in Ontario between 2005 and 2010. ED visits at any hospital in the preceding 5 days were identified as potential repeated ED visits. We used generalized estimating equations to model the association of sex, age, triage score, immunocompromised state, visit timing, type of ED, and annual patient volume on the risk of repeated ED visits. RESULTS: Of 521 children, 114 (21.9%) had repeated ED visits before admission. Children admitted on initial visit and those with repeated visits had similar median lengths of stay (13 versus 12 days), critical care use (21.1% versus 16.7%), and mortality (mean 2.9%). One in 3 children repeating visits returned to a different hospital. Repeated visits were associated with older age, a less acute triage score, and initial visit to a community hospital without available pediatric consultation. CONCLUSION: In this cohort, repeated ED visits among children with meningitis or septicemia were common, yet they had health outcomes similar to those of children admitted on initial visit. One in 3 returned to a different ED, making it unlikely that EDs and clinicians can learn from these critical events without a regionalized reporting system.

Risk of cerebral palsy among the offspring of immigrants.

BACKGROUND: Cerebral palsy (CP) has a multifactorial etiology, and placental vascular disease may be one major risk factor. The risk of placental vascular disease may be lower among some immigrant groups. We studied the association between immigrant status and the risk of CP. METHODS: We conducted a population-based retrospective cohort study of all singleton and twin livebirths in Ontario between 2002-2008, and who survived ≥28 days after birth. Each child was assessed for CP up to age 4 years, based on either a single inpatient or ≥2 outpatient pediatric diagnoses of CP. Relative to non-immigrants (n = 566,668), the risk of CP was assessed for all immigrants (n = 177,390), and further evaluated by World region of origin. Cox proportional hazard ratios (aHR) were adjusted for maternal age, income, diabetes mellitus, obesity, tobacco use, Caesarean delivery, year of delivery, physician visits, twin pregnancy, preterm delivery, as well as small- and large-for-gestational age birthweight. RESULTS: There were 1346 cases of CP, with a lower rate among immigrants (1.45 per 1000) than non-immigrants (1.92 per 1000) (aHR 0.77, 95% confidence interval [CI] 0.67 to 0.88). Mothers from East Asia and the Pacific (aHR 0.54, 95% CI 0.39 to 0.77) and the Caribbean (aHR 0.58, 95% CI 0.37 to 0.93) were at a significantly lower risk of having a child with CP. Whether further adjusting for preeclampsia, gestational hypertension, placental abruption or placental infraction, or upon using a competing risk analysis that further accounted for stillbirth and neonatal death, these results did not change. CONCLUSIONS: Immigration and ethnicity appear to attenuate the risk of CP, and this effect is not fully explained by known risk factors.

Socioeconomic status and the use of computed tomography in the emergency department.

BACKGROUND: Low socioeconomic status (SES) is associated with adverse health outcomes. Possible explanations include differences in health status, access to health care, and care provided by clinicians. We sought to determine whether SES is associated with computed tomography (CT) use in the emergency department (ED). METHODS: A retrospective cohort study of all Ontario ED patients (April 1, 2009, to March 31, 2010) using administrative databases was conducted, and patients were stratified into SES quintiles based on median neighbourhood income. Using multivariate logistical regression, CT scan use within SES quintiles was compared for all patients and subgroups based on chief complaints: headache, abdominal pain, and complex abdominal pain (age ≥ 65 years, high acuity, and admittance to hospital). RESULTS: We analyzed 4,551,101 patient visits, of which 52% were female. Overall, 8.2% underwent CT scanning. In adjusted analyses, the lowest SES patients were less likely to undergo CT scanning overall and in all clinical subgroups, except for complex abdominal pain. Compared to the lowest SES quintile, the adjusted odds ratios of CT scanning in the highest SES quintile were 1.08 (95% CI 1.07-1.09), 1.28 (95% CI 1.22-1.34), and 1.24 (95% CI 1.21-1.27) for all patients, headache pain patients, and abdominal pain patients, respectively. For patients presenting with complex abdominal pain, no significant difference in CT use was observed. CONCLUSION: Lowest SES ED patients were less likely to receive CT scans overall and in headache and abdominal pain subgroups. No difference was seen among complex abdominal pain patients, suggesting that as clinical indications for the test become more clearcut, use across SES quintiles differs less.

Evaluation of an emergency department lean process improvement program to reduce length of stay.

STUDY OBJECTIVE: In recent years, lean principles have been applied to improve wait times in the emergency department (ED). In 2009, an ED process improvement program based on lean methods was introduced in Ontario as part of a broad strategy to reduce ED length of stay and improve patient flow. This study seeks to determine the effect of this program on ED wait times and quality of care. METHODS: We conducted a retrospective cohort study of all ED visits at program and control sites during 3 program waves from April 1, 2007, to June 30, 2011, in Ontario, Canada. Time series analyses of outcomes before and after the program and difference-in-differences analyses comparing changes in program sites with control sites were conducted. RESULTS: In before-after models among program sites alone, 90th percentile ED length of stay did not change in wave 1 (-14 minutes [95% confidence interval {CI} -47 to 20]) but decreased after wave 2 (-87 [95% CI -108 to -66]) and wave 3 (-33 [95% CI -50 to -17]); median ED length of stay decreased after wave 1 (-18 [95% CI -24 to -12]), wave 2 (-23 [95% CI -27 to -19]), and wave 3 (-15 [95% CI -18 to -12]). In all waves, decreases were observed in time to physician assessment, left-without-being-seen rates, and 72-hour ED revisit rates. In the difference-in-difference models, in which changes in program sites were compared with controls, the program was associated with no change in 90th percentile ED length of stay in wave 2 (17 [95% CI -0.2 to 33]) and increases in wave 1 (23 [95% CI 0.9 to 45]) and wave 3 (31 [95% CI 10 to 51]), modest reductions in median ED length of stay in waves 2 and 3 alone, and a decrease in time to physician assessment in wave 3 alone. CONCLUSION: Although the program reduced ED waiting times, it appeared that its benefits were diminished or disappeared when compared with that of control sites, which were exposed to system-wide initiatives such as public reporting and pay for performance. This study suggests that further evaluation of the effectiveness of lean methods in the ED is warranted before widespread implementation.