Canadian Benchmark Research Articles

Adaptive protection coordination in microgrid based on nature inspired meta-heuristic optimization algorithm

Ensuring a robust protection system is crucial for safeguarding the integrity of the overall system against abnormalities. Incorporating distributed generation (DG) into the distribution network can introduce fluctuations in fault current levels and directions, potentially causing mismatches in the response of the existing coordination system. This study proposes an adaptive protection coordination scheme designed to accommodate both grid-connected and standalone modes, addressing various fault scenarios. Utilizing a hybrid WCMFO algorithm, optimal relay settings are determined to facilitate effective coordination within a microgrid setup. The proposed method has been analyzed on 9 bus Canadian benchmark system integrated with four DGs. The performance of the proposed method is compared to other optimization techniques to demonstrate its effectiveness. System modelling is conducted using MATLAB/Simulink, and validation is further carried out using industrial ETAP software on a test microgrid system. The analysis extends to evaluating the enhancement in overall system reliability, quantified in terms of energy not supplied (ENS).

Harmonic Dual-Setting Directional Overcurrent Protection for Inverter-Based Islanded Microgrids

Limited fault currents in inverter-interfaced islanded microgrids impose immense challenges on conventional overcurrent protection schemes. This paper proposes a sensitive and selective protection scheme for islanded microgrids using a third harmonic voltage generated by inverter-interfaced distributed generators (IIDGs). The generated harmonic voltage results in a harmonic layer formed during short-circuit faults and is decoupled from the fundamental fault current, i.e., limited by IIDGs. Further, the generated harmonic voltage is adaptively adjusted based on fault severity to enhance protection sensitivity and obtain a universal set of relays’ settings. The proposed protection scheme utilizes harmonic directional overcurrent relays (HDOCRs) equipped with a dual-setting time-current-voltage setting that sense the generated harmonic voltages and currents at the relay location to ensure optimal protection coordination (OPC) of islanded microgrids. The OPC with the proposed dual-setting is formulated as a constrained nonlinear program to determine the optimal forward and reverse relays’ settings. The proposed scheme is tested on the Canadian benchmark urban distribution system and compared to the conventional protection scheme, which relies only on a single time-current-voltage trip characteristic. The results ensure the ability of the proposed scheme to protect islanded microgrids without communication and its capability to reduce relays’ operation times.

Real-World Results of Autologous Stem Cell Transplantation in Newly Diagnosed Patients with Multiple Myeloma: A Multi-Institutional Report from the Canadian Myeloma Research Group (CMRG) Database

INTRODUCTION Autologous stem cell transplant (ASCT) remains an important option for eligible multiple myeloma (MM) patients (pts) as part of initial therapy. In Canada, fit younger pts are typically offered ASCT; selected centers offer tandem ASCT to high-risk (HR) pts; and current standard practice involves continuation of maintenance (maint) therapy until disease progression, which is facilitated by public funding for lenalidomide (len) in this setting. Using our national database, we examined the details and outcomes of ASCT performed as part of initial therapy in eligible Canadian MM pts. Methods The Canadian Myeloma Research Group database (CMRG-DB) contains both legacy and ongoing prospective data and can track and characterize real-world outcome of pts treated at 17 major Canadian institutions. All pts who received an ASCT as part of initial MM therapy between 01/Jan/2007 to 31/Dec/2021 were included. Progression-free survival (PFS) was calculated from the time of first ASCT until disease progression, death due to any cause or last follow up, whichever comes first, while overall survival (OS) was defined as the time from ASCT to the date of death or last follow up. Results 3821 pts underwent ASCT as frontline therapy and were included in the analysis. Median age was 61 (range 26-77) years, 15.2% had a creatinine > 177 umol/L and 18% had HR FISH [del17p, t(4;14) and t(14;16)] (FISH was unknown/missing in 50% of pts). The majority (82%) received bortezomib (btz)-based induction; this consisted of CyBorD in 72% with rates of ≥PR (≥VGPR) of 92% (60%). Only 1.6% received a proteasome inhibitor (PI) + len; rates of ≥PR (≥VGPR) were 96.5% (63.2%) in this subgroup. Median time to ASCT from start of induction was 5.6 months (mos). A second induction regimen, including len in 78.5%, was administered to 376 pts for suboptimal response/progression on first induction. The ≥PR (≥VGPR) rates in these 376 pts was 72.9% (35.4%) with a median time from start of second induction to ASCT of 4.2 mos. Tandem ASCT was performed in 314 pts, primarily in HR pts (64%). In HR FISH pts, the median PFS (mPFS) for single vs tandem ASCT was 25.1 vs 35.4 mos (p 0.018) and median OS (mOS) 91.5 vs 84.4 mos (p 0.048), respectively. For those without HR FISH, mPFS and mOS for single vs tandem ASCT were, respectively, 46.5 vs 33.8 mos (p <0.001) and 158.6 vs NYR (p <0.001). After ASCT, only 205 (5%) pts received consolidation that consisted of a PI + len in 93.2%. However, 2060 pts (53.9%) received post-ASCT maint (len +/- steroids in 63.1%, btz +/- steroids in 2.1 %, len + btz +/- steroids in 1.7%, other PI +/- steroids in 1.6%, len + other PI +/- steroids in 5.7 % and thalidomide +/- steroids in 8.5%). The mPFS and mOS for all pts was 35.4 mos (95% CI 33.7-37.3) and 125 mos (95% CI 120-138) from first ASCT. Table 1 summarizes the mPFS and mOS according to treatment. Those given a second induction regimen had significantly inferior outcomes (mPFS 27.9 vs 36.2 mos [p 0.001]; mOS 118 vs 126 mos [p 0.011]), although the use of maintenance led to comparable results regardless of number of induction regimens (mPFS 55.3 vs 51.1 mos [p 0.11]; mOS 158.6 vs not yet reached (NYR) [p 0.13]). Consolidation pts had a better mPFS (55.3 vs 34.4 mos [p 0.001]), but no significant gain in mOS (p 0.065). The mPFS and mOS were 48.8 vs 24.5 mos and 159 vs 105 mos for the maint vs non-maint cohorts, respectively, when all types of maint were included. For pts receiving len, btz or both (+/- steroids), the mPFS was 53.7 mos vs 48.2 mos vs 43.5 mos, respectively, while the mOS was 159 mos vs NYR vs 115 mos, respectively. Amongst pts receiving such maint, outcomes for pts with HR FISH were compared with those without HR FISH: mPFS was 36.6 mos vs 55.2 mos and the mOS was 97.4 mos vs 164.4 mos, respectively. CONCLUSIONS This large study demonstrates that the integration of btz and len into the transplant sequence produces a mOS of ≥10 yrs in most ASCT pts in the real-world setting. Our observations highlight the contribution of post-ASCT maint, particularly len given until progression, when used in multiple pt groups including those with and without HR, as well as those requiring a second induction regimen. Nevertheless, HR pts require additional strategies to optimize results. Further analyses to assess the relationship of pt characteristics, specific treatment details and outcomes are in progress. These results serve as Canadian benchmarks for comparison with newer approaches that combine immunotherapy with ASCT as initial therapy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Impact Assessment and Mitigation Techniques for High Penetration Levels of Renewable Energy Sources in Distribution Networks: Voltage-control Perspective

The integration of renewable distributed generation (RDG) into distribution networks is promising and increasing nowadays. However, high penetration levels of distributed generation (DG) are often limited as they may have an adverse effect on the operation of distribution networks. One of the operation challenges is the interaction between DG and voltage-control equipment, e. g., an under-load tap changer (ULTC), which is basically designed to compensate for voltage changes caused by slow load variations. The integration of variable DGs leads to rapid voltage fluctuations, which can negatively affect the tap operation of ULTC. This paper investigates the impact of high penetration levels of RDG on the tap operation of ULTC in distribution networks through simulations. Various mitigation techniques that can alleviate this impact are also examined. Among these techniques, constant power-factor mode is regarded as the best trade-off between the simplicity and effectiveness of minimizing the number of tap operations. Simulations are performed on a Canadian benchmark rural distribution feeder using OpenDSS software.

An assessment of uranium in groundwater in the Grand Canyon region

The Grand Canyon region in northern Arizona is a home or sacred place of origin for many Native Americans and is visited by over 6 million tourists each year. Most communities in the area depend upon groundwater for all water uses. Some of the highest-grade uranium ore in the United States also is found in the Grand Canyon region. A withdrawal of over 4000 km2 of Federal land in the Grand Canyon region from new uranium mining activities for 20 years was instituted in 2012, owing in part to a lack of scientific data on potential effects from uranium mining on water resources in the area. The U.S. Geological Survey has collected groundwater chemistry samples since 1981 in the Grand Canyon region to better understand the current state of groundwater quality, to monitor for changes in groundwater quality that may be the result of mining activities, and to identify "hot spots" with elevated metal concentrations and investigate the causes. This manuscript presents results for the assessment of uranium in groundwater in the Grand Canyon region. Analytical results for uranium in groundwater in the Grand Canyon region were available for 573 samples collected from 180 spring sites and 26 wells from September 1, 1981 to October 7, 2020. Samples were collected from springs issuing from stratigraphic units above, within, and below the Permian strata that host uranium ore in breccia pipes in the area. Maximum uranium concentrations at groundwater sites in the region ranged from less than 1 µg/L at 23 sites (11%) to 100 µg/L or more at 4 sites (2%). Of the 206 groundwater sites sampled, 195 sites (95%) had maximum observed uranium concentrations less than the U.S. Environmental Protection Agency’s Maximum Contaminant Level of 30 µg/L for drinking water and 177 sites (86%) had uranium concentrations less than the 15 µg/L Canadian benchmark for protection of aquatic life in freshwater. The establishment of baseline groundwater quality is an important first step in monitoring for change in water chemistry throughout mining lifecycles and beyond to ensure the health of these critical groundwater resources.

Quality of End-of-Life Care for People with Advanced Non-Small Cell Lung Cancer in Ontario: A Population-Based Study.

Ensuring high quality end of life (EOL) care is necessary for people with advanced non-small-cell lung cancer (NSCLC), given its high incidence, mortality and symptom burden. Aggressive EOL care can adversely affect the quality of life of NSCLC patients without providing meaningful oncologic benefit. Objectives: (1) To describe EOL health services quality indicators and timing of palliative care consultation provided to patients dying of NSCLC. (2) To examine associations between aggressive and supportive care and patient, disease and treatment characteristics. Methods: This retrospective population-based cohort study describes those who died of NSCLC in Ontario, Canada from 2009–2017. Socio-demographic, patient, disease and treatment characteristics as well as EOL health service quality and use of palliative care consultation were investigated. Multivariable logistic regression models examined factors associated with receiving aggressive or supportive care. Results: Aggressive care quality indicators were present in 50.3% and supportive care indicators in 60.3% of the cohort (N = 37,203). Aggressive care indicators decreased between 2009 and 2017 (57.4% to 45.3%) and increased for supportive care (54.2% to 67.5%). Benchmarks were not met by 2017 in 3 of 4 cases. Male sex and greater comorbidity were associated with more aggressive EOL care and less supportive care. Older age was negatively associated and rurality positively associated with aggressive care. No palliative care consultation occurred in 56.0%. Conclusions: While improvements in the use of supportive rather than aggressive care were noted, established Canadian benchmarks were not met. Moreover, there is variation in EOL quality between groups and use of earlier palliative care must improve.

Defining appropriate antibiotic prescribing in primary care: Amodified Delphi panel approach.

Antimicrobial overuse contributes to antimicrobial resistance. In the ambulatory setting, where more than 90% of antibiotics are dispensed, there are no Canadian benchmarks for appropriate use. This study aims to define the expected appropriate outpatient antibiotic prescribing rates for three age groups (<2, 2-18, >18 years) using a modified Delphi method. We developed an online questionnaire to solicit from a multidisciplinary panel (community-academic family physicians, adult-paediatric infectious disease physicians, and antimicrobial stewardship pharmacists) what percentage of 23 common clinical conditions would appropriately be treated with systemic antibiotics followed with in-person meetings to achieve 100% consensus. The panelists reached consensus for one condition online and 22 conditions face-to-face, which took an average of 2.6 rounds of discussion per condition (range, min-max 1-5). The consensus for appropriate systemic antibiotic prescribing rates were, for pneumonia, pyelonephritis, non-purulent skin and soft tissue infections (SSTI), other bacterial infections, and reproductive tract infections, 100%; urinary tract infections, 95%-100%; prostatitis, 95%; epididymo-orchitis, 85%-88%; chronic obstructive pulmonary disease, 50%; purulent SSTI, 35%-50%; otitis media, 30%-40%; pharyngitis, 18%-40%; acute sinusitis, 18%-20%; chronic sinusitis, 14%; bronchitis, 5%-8%; gastroenteritis, 4%-5%; dental infections, 4%; eye infections, 1%; otitis externa, 0%-1%; and asthma, common cold, influenza, and other non-bacterial infections (0%). (Note that some differed by age group.). This study resulted in expert consensus for defined levels of appropriate antibiotic prescribing across a broad set of outpatient conditions. These results can be applied to community antimicrobial stewardship initiatives to investigate the level of inappropriate use and set targets to optimize antibiotic use.

The effect of US macroeconomic news announcements on the Canadian stock market: Evidence using high-frequency data

We analyze the impact of US macroeconomic news announcements on the Canadian benchmark stock index return and volatility using high-frequency 5-min data. Our findings reveal that several US news releases exert a statistically significant influence on the Canadian stock market return and volatility. Moreover, we show that during the 2008 US recession, slightly more US news announcements exhibit significant impacts on the Canadian equity returns, with relatively pronounced effects. Overall, our results support previous findings by suggesting that US macroeconomic fundamentals form a linkage between Canadian and US financial markets.

Fault Current Limiter Placement to Reduce Recloser ‑ Fuse Miscoordination in Electric Distribution Systems with Distributed Generation using Multiobjective Particle Swarm Optimization

This paper presents a method to minimize protective devices in electric distribution systems with Distributed Generation (DG). With the growing penetration of DG in distribution systems, the main practice to maintain protective devices coordination during a fault is to disconnect all DG sources. This practice nullifies the benefits brought by DG in distribution systems, mainly because the majority of faults are proven to be temporary. To solve this problem, this paper proposes the allocation of fault current limiters (FCL), which consist in inert devices on system's normal operation, but insert a high impedance value in series with feeders when a fault occurs, thus, limiting is magnitude. FCL placement is treated as a multiobjective optimization problem, aiming to reduce fault currents difference between situations with DG and without DG penetration. Also, FCL size must be minimized, aiming to reduce costs. The search for the optimal solution is made using multiobjective particle swarm optimization and the method is tested on the Canadian Benchmark Test System, showing great efficiency.

Canadian benchmarks for acute injury care.

Acute care injury outcomes vary substantially across Canadian provinces and trauma centres. Our aim was to develop Canadian benchmarks to monitor mortality and hospital length of stay (LOS) for injury admissions. Benchmarks were derived using data from the Canadian National Trauma Registry on patients with major trauma admitted to any level I or II trauma centre in Canada and from the following patient subgroups: isolated traumatic brain injury (TBI), isolated thoracoabdominal injury, multisystem blunt injury, age 65 years or older. We assessed predictive validity using measures of discrimination and calibration, and performed sensitivity analyses to assess the impact of replacing analytically complex methods (multiple imputation, shrinkage estimates and flexible modelling) with simple models that can be implemented locally. The mortality risk adjustment model had excellent discrimination and calibration (area under the receiver operating characteristic curve 0.886, Hosmer-Lemeshow 36). The LOS risk-adjustment model predicted 29% of the variation in LOS. Overall, observed:expected ratios of mortality and mean LOS generated by an analytically simple model correlated strongly with those generated by analytically complex models (r > 0.95, κ on outliers > 0.90). We propose Canadian benchmarks that can be used to monitor quality of care in Canadian trauma centres using Excel (see the appendices, available at canjsurg.ca). The program can be implemented using local trauma registries, providing that at least 100 patients are available for analysis.

Energy consumption analysis of school buildings in Manitoba, Canada

Abstract Buildings contribute 20–40% of the world’s energy consumption, making the need to investigate their energy performance a necessity. Given the lack of empirical evidence on the energy performance of school buildings in cold climates, this study aimed to benchmark historical energy consumption over a ten-year period in a sample of 30 school buildings in Manitoba, Canada. Results showed the median total energy consumption of these schools was higher than other Canadian benchmarks. School building age had a statistically significant effect on their energy consumption, with newer schools consuming less gas but more electricity than older and middle-aged ones. The retrofits implemented in some schools did not for the most part have a statistically significant effect on their energy consumption, although a decrease in energy consumption was observed. The results also showed that middle-aged schools were the largest energy consumers, with the results changing depending on the metric used to report on schools’ energy consumption, reinforcing the need to standardize those metrics. There is also a need to investigate how occupancy may be contributing to the increase in electricity consumption in newer schools. This study is the first to provide empirical evidence on existing school buildings’ energy consumption in Manitoba, establishing benchmarks that practitioners can make use of in similar cold climates.

Cervical cancer screening for survivors diagnosed with cancer before age 25.

The study aims to better understand Pap test utilization for cancer survivors diagnosed before age 25 in British Columbia (BC), Canada. A population-based cross-sectional data linkage study that included 1285 5-year female cancer survivors diagnosed with cancer before age 25 and 12,185 randomly selected and birth-year-matched BC female residents. Pap participation rates in 2008-2010, both uncorrected and corrected for hysterectomy status, were compared between two groups. Adjusted prevalence ratios (PRadj) were calculated to examine (1) associations between factors and Pap rates in each group and (2) interactions between factors and groups, using log-binomial regression models. Overall Pap rates, both uncorrected and corrected, were higher for survivors (71.8%; 72.9%) than population (69%; 69.7%). Pap rates were 4.8-5.1 and 17.8-22.4% higher for survivors aged 30-39 and 50-59 respectively. Significantly higher Pap test utilization was associated with previous Pap tests (PRadj=1.83, 95%CI=1.76-1.89) and previous cervical procedures (1.20, 95%CI=1.15-1.25). Hysterectomy rates were doubled for survivors (7.4%) than population (3.7%). This did not affect Pap participation rate comparisons between two groups. In both groups, 51.6-70% of females with hysterectomies still received Pap tests. Survivors' Pap test utilization was significantly higher than population, but lower than the Canadian benchmark of 90%. Hysterectomy correction does not affect this observation. Cervical cancer screening is suboptimal for survivors. Females with prior hysterectomies might have received unnecessary Pap tests. Survivors without prior hysterectomies should continue to undergo Pap tests recommended by provincial guidelines, to optimize their health.

Efficient Algorithm for Scalable Event-Based Demand Response Management in Microgrids

Demand response management has become one of the key enabling technologies for smart grids. Motivated by the increasing demand response incentives offered by service operators, more customers are subscribing to various demand response programs. However, with growing customer participation, the problem of determining the optimal loads to be curtailed in a microgrid during contingencies within a feasible time frame becomes computationally hard. This paper proposes an efficient approximation algorithm for event-based demand response management in microgrids. In event-based management, it is important to curtail loads as fast as possible to maintain the stability of a microgrid during the islanded mode in a scalable manner. A simple greedy approach is presented that can rapidly determine a close-to-optimal load curtailment scheme to maximize the aggregate customer utility in milliseconds for a large number of customers. This paper further derives a novel theoretical guarantee of the gap between the proposed efficient algorithm and the optimal solution (that may be computationally hard to obtain). The performance of algorithm is corroborated extensively by simulations with up to thousands of customers. For the sake of practicality, the proposed event-based demand response management algorithm is applied to a feeder from the Canadian benchmark distribution system. The simulation results demonstrate that the proposed approach efficiently optimizes microgrid operation during islanded mode while maintaining appropriate voltage levels and network constrains.

Occurrence, spatial deposition and footprint of polybrominated diphenyl ethers in surficial sediments of Bushehr peninsula, the Persian Gulf

The concentrations of polybrominated diphenyl ethers (PBDEs) were determined in the surficial sediments of Bushehr coasts, the Persian Gulf. Eighteen samples were collected from 6 sites at distances of 500, 1000 and 1500m from the coast. PBDEs were detected in all the samples, indicating their widespread occurrence in marine sediments of the studied area. BDE-209 and ∑7PBDEs were in the range of n.d. (not detected) to 6.29ngg−1 and n.d. to 0.62ngg−1 dw, respectively. The studied area can be classified as the region with the minimal contamination values reported globally as yet. The concentrations of PBDEs were lower than the Canadian benchmarks, and risk quotient assessments demonstrated low ecological risk. BDE-183 and then BDE-153 were the congeners with the highest detection frequencies in the stations, confirming extensive occurrence of Octa-mix in the studied area.

Assessing occupant satisfaction and energy behaviours in Toronto’s LEED gold high-rise residential buildings

Purpose – This paper aims to present four purposes: to assess occupant satisfaction with indoor environmental quality (IEQ); to determine if occupants appear to be operating their dwellings in an energy efficient manner; to suggest ways that occupant satisfaction and behaviour can help or hinder energy efficiency; and to show that the post-occupancy evaluation approach is an effective tool in diagnosing and improving satisfaction and energy efficiency in high-rise residential buildings. Design/methodology/approach – Beyond measuring occupant satisfaction with IEQ, this paper uses scores and user comments from occupant questionnaires to identify success and indicate frustration and/or confusion with particular building technologies. It also extrapolates the energy efficiency implications of these responses in four Leadership in Energy and Environmental Design Gold residential towers. Findings – The research highlights where problems occur, particularly with the adoption of new technologies which may not be well understood by the occupants. It also identifies behaviour patterns that may negate energy efficiency strategies. Research limitations/implications – The lack of dwelling metre data prevents this research from making causal links between behaviours and their energy implications. Also, the lack of Canadian benchmarks for satisfaction of occupants means that comparisons can only be made to cases from the UK, which is less robust. Originality/value – This type of work has never been done in Canadian residential high rise towers before. It helps to better understand the process of ensuring that occupants successfully adopt innovation that can lead to energy savings.

Stage, treatment and outcomes for patients with breast cancer in British Columbia in 2002: a population-based cohort study.

There are very few long-term Canadian data on breast cancer outcomes by stage. We described the stage, treatment and outcomes of breast cancer at a population level for patients in British Columbia. This population-based cohort study included almost all patients with incident breast cancer registered in 2002 (about 97.6% registry case completeness). For these patients, information on stage, primary local surgery, radiotherapy, chemotherapy, hormone therapy and survival outcome (based on registry date and cause-of-death data) were available. We calculated Kaplan-Meier curves for breast cancer-specific survival and overall survival by stage and analyzed prognostic and treatment factors with a multivariable Cox model. The 2927 incident cases of breast cancer identified in 2002 had the following distribution by stage: stage 0 (in situ), 424 (14%); stage I, 1118 (38%); stage II, 938 (32%); stage III, 233 (8%); stage IV, 123 (4%); unknown, 91 (3%). The distribution of patients' ages was <40 years, 127 (4%); 40-49, 538 (18%); 50-59, 719 (25%); 60-69, 660 (23%); 70-79, 583 (20%); ≥80, 300 (10%). Within the first year after diagnosis, radiotherapy was provided to 1649 patients (56%), chemotherapy to 928 (32%) and hormone therapy to 1664 (57%). Ten-year breast cancer-specific survival rates by stage were > 99% for stage 0, 95% for stage I, 81% for stage II, 55% for stage III and 4% for stage IV. Ten-year overall survival rates were 89% for stage 0, 81% for stage I, 68% for stage II, 43% for stage III and 2% for stage IV. This analysis provides a Canadian benchmark for treatment rates and 10-year outcomes by stage for all incident cases of breast cancer in a single province. Outcomes in British Columbia compared well with published rates for the United States and Europe.

Indications for, Timing of, and Modes of Delivery in a National Cohort of Women Admitted With Antepartum Hemorrhage at 22+0 to 28+6 Weeks’ Gestation

ObjectiveAntepartum hemorrhage is associated with preterm birthand operative delivery. Since the Canadian Perinatal Networkrecords obstetric interventions for women admitted to tertiarycare hospitals with antepartum hemorrhage, our objective was todescribe the delivery characteristics of this cohort. MethodsTrained abstractors collected data by chart review fromwomen admitted with antepartum hemorrhage between 22+0 and28+6 weeks’ gestation. We included all women with completefollow-up postpartum and used descriptive statistics to report theindications for, timing of, and modes of delivery. ResultsThe study cohort included 806 women from 13 tertiaryperinatal centres in six provinces. The most common causes ofbleeding were placental abruption (n = 256) and placenta previa(n = 171). The median gestational age at delivery was 30 weeks,and 497 (61.7%) births occurred at less than 34 weeks. Over onehalf of the women began labour spontaneously, and 238 (29.5%)were delivered prior to the onset of labour. Overall, 370 (45.9%)women delivered vaginally, including 98 who had induction oflabour. Of the 436 Caesarean sections (54.1%), 345 (79.1%)were emergencies. The most common indications for Caesareansection were placenta previa, abnormal fetal presentation, andplacental abruption or vaginal bleeding. ConclusionThis inpatient cohort of women with antepartumhemorrhage had high rates of spontaneous labour, preterm birth,and emergency Caesarean section. These results can be used ascurrent Canadian benchmark rates of preterm delivery, inductionof labour, and Caesarean section in women admitted to tertiarycare centres with antepartum hemorrhage between 22+0 and 28+6weeks’ gestation, and can aid in the counselling of similar women.

The analysis of mainstream smoke emissions of Canadian ‘super slim’ cigarettes

Super slim cigarettes are a relatively new type of cigarette in Canada, and an analysis of select toxicants in the mainstream smoke emissions of the super slim cigarette was conducted. The yields of selected toxicants in the mainstream smoke emissions of six brands of super slim cigarettes were compared with the Canadian Benchmark, which represents the cigarette designs most commonly found in Canada. A super slim cigarette was also compared with a 'Reference Cigarette' to study the impact of the significantly reduced circumference on mainstream smoke emissions. Compared with the Canadian Benchmark, the yields of carbon monoxide, the carbonyls, volatiles and the aromatic amines were significantly lower for the super slim cigarette, but the yields of formaldehyde and ammonia were significantly higher. For brands containing a mixed tobacco blend, the yields of tobacco-specific nitrosamines were increased significantly. The reduced circumference of the super slim cigarette resulted in a lower tobacco weight, which together with filter ventilation resulted in lower yields of many toxicants. However, the reduced circumference increased significantly the yields of formaldehyde and phenols in mainstream smoke emissions. The notably slimmer design of the super slim cigarette resulted in lower yields of some toxicants in the mainstream smoke emissions. However, there were also significant increases in some toxicant levels in the mainstream smoke emissions including formaldehyde, ammonia and the phenols. There are no changes in emission levels that have been shown to reduce exposure or risk in a way that is meaningful, and therefore, the super slim cigarette should not be considered a 'less harmful' cigarette.

130 Meeting established canadian benchmarks for access to heart failure (HF) care following emergency department visit and association with outcome

130 Meeting established canadian benchmarks for access to heart failure (HF) care following emergency department visit and association with outcome

Use of Evidence-Based Therapy at Discharge for Patients with Acute Myocardial Infarction: Retrospective Audit of Medical Records

Various guidelines are available outlining optimal therapy for patients with acute myocardial infarction. Canadian institutions providing care for such patients have been encouraged to evaluate their care processes using specific indicators. To determine the proportion of patients with acute myocardial infarction discharged from a single health authority for whom acetylsalicylic acid (ASA), adrenergic β-receptor antagonists (β-blockers), angiotensin-converting enzyme (ACE) inhibitors, or 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) had been prescribed. Patients treated over a 12-month period (April 1, 2004, to March 31, 2005) for whom the most responsible diagnosis was acute myocardial infarction were eligible for inclusion in this review. Retrieved data included diagnosis, demographic information, comorbidities, and medications at the time of admission and discharge. Rates of discharge prescribing for the 4 drug classes were calculated for all patients and for "ideal" patients (those without documented contraindications). Rates were compared with published benchmark values. Medical records for a total of 346 eligible patients were reviewed. Mean age was 65.3 years (standard deviation 13.4 years), and 226 (65.3%) of the patients were male. The coded diagnosis was ST-elevation myocardial infarction for 91 patients (26.3%), non-ST-elevation myocardial infarction for 164 (47.4%), and myocardial infarction not specified for 91 (26.3%). For "ideal" patients, the prescribing rates were 99.0% (308 of 311 patients) for ASA, 96.3% (310 of 322 patients) for β-blockers, 90.4% (264 of 292 patients) for ACE inhibitors, and 88.8% (278 of 313 patients) for statins. Rates of prescribing of ASA, β-blockers, ACE inhibitors, and statins for "ideal" patients discharged after treatment for acute myocardial infarction exceeded the published Canadian benchmark rates (≥ 90% for ASA, ≥ 85% for β-blockers and ACE inhibitors, ≥ 70% for statins).