Jeffrey  A. Bakal

Dr. Jeffrey A. Bakal

Provincial Research Data Services, Faculty of Medicine & Dentistry, Medicine Department, University of Alberta, Edmonton, AB, Canada

Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 January 2012 in Statistical Methods in Medical Research
Verified
Journal Article
Closed access
JBJeffrey A. Bakal
Jeffrey A. Bakal
CWCynthia Westerhout
Cynthia Westerhout
PAPaul W Armstrong
Paul W Armstrong
Composite endpoints are commonly used in cardiovascular clinical trials. When using a composite endpoint a subject is considered to have an event when the first component endpoint has occurred. The use of composite endpoints offers the ability to incorporate several clinically important endpoint events thereby augmenting the event rate and increasing statistical power for a given sample size. One assumption of the composite is that all component events are of equal clinical importance. This assumption is rarely achieved given the diversity of component endpoints included. One means of adjusting for this diversity is to adjust the outcomes using severity weights determined a priori. The use of a weighted endpoint also allows for the incorporation of multiple endpoints per patient. Although weighting the outcomes lowers the effective number of events, it offers additional information that reduces the variance of the estimate. We created a series of simulation studies to examine the effect on power as the individual components of a typical composite were changed. In one study, we noted that the weighted composite was able to offer discriminative power when the component outcomes were altered, while the traditional method was not. In the other study, we noted that the weighted composite offered a similar level of power to the traditional composite when the change was driven by the more severe endpoints.

7 February 2023 in Journal of the American Heart Association
Verified
Journal Article
Closed access
FMFinlay McAlister
Finlay McAlister
ZHZoe Hsu
Zoe Hsu
YDYuan Dong
Yuan Dong
RTRoss Tsuyuki
Ross Tsuyuki
CWCarl van Walraven
Carl van Walraven
JBJeffrey A. Bakal
Jeffrey A. Bakal
Background: Because the impact of changes in how outpatient care was delivered during the COVID‐19 pandemic is uncertain, we designed this study to examine the frequency and type of outpatient visits between March 1, 2019 to February 29, 2020 (prepandemic) and from March 1, 2020 to February 28, 2021 (pandemic) and specifically compared outcomes after virtual versus in‐person outpatient visits during the pandemic. Methods and Results: Population‐based retrospective cohort study of all 3.8 million adults in Alberta, Canada. We examined all physician visits and 30‐ and 90‐day outcomes, with a focus on those adults with the cardiovascular ambulatory‐care sensitive conditions heart failure, hypertension, and diabetes. Our primary outcome was emergency department visit or hospitalization, evaluated using survival analysis accounting for competing risk of death. Although in‐person outpatient visits decreased by 38.9% in the year after March 1, 2020 (10 142 184 versus 16 592 599 in the prior year), the introduction of virtual visits (7 152 147; 41.4% of total) meant that total outpatient visits increased by 4.1% in the first year of the pandemic for Albertan adults. Outpatient visit frequency (albeit 41.4% virtual, 58.6% in‐person) and prescribing patterns were stable in the first year after pandemic onset for patients with the cardiovascular ambulatory‐care sensitive conditions we examined, but laboratory test frequency declined by 20% (serum creatinine) to 47% (glycosylated hemoglobin). In the first year of the pandemic, virtual outpatient visits were associated with fewer subsequent emergency department visits or hospitalizations (compared with in‐person visits) for patients with heart failure (adjusted hazard ratio [aHR], 0.90 [95% CI, 0.85–0.96] at 30 days and 0.96 [95% CI, 0.92–1.00] at 90 days), hypertension (aHR, 0.88 [95% CI, 0.85–0.91] and 0.93 [95% CI, 0.91–0.95] at 30 and 90 days), or diabetes (aHR, 0.90 [95% CI, 0.87–0.93] and 0.93 [95% CI, 0.91–0.95] at 30 and 90 days). Conclusions: The adoption and rapid uptake of virtual outpatient care during the COVID‐19 pandemic did not negatively impact frequency of follow‐up, prescribing, or short‐term outcomes, and could have potentially positively impacted some of these for adults with heart failure, diabetes, or hypertension in a setting where there was an active reimbursement policy for virtual visits. Given declines in laboratory monitoring and screening activities, further research is needed to evaluate whether long‐term outcomes will differ.

30 August 2022 in IJID Regions
Verified
Journal Article
Open access
SBSanjay Beesoon
Sanjay Beesoon
JBJeffrey A. Bakal
Jeffrey A. Bakal
EYErik Youngson
Erik Youngson
KWKienan Williams
Kienan Williams
SBSandra A. Berzins
Sandra A. Berzins
AJA. Mark Joffe
A. Mark Joffe
To determine if there was excess mortality in Alberta, Canada during the coronavirus disease 2019 (COVID-19) pandemic, to confirm if excess mortality affected all age groups equally, and to determine what proportions of excess deaths were directly related to COVID-19 and non-pharmaceutical drug poisoning. Weekly all-cause data used to estimate excess mortality were modelled against the pre-pandemic period (January 2015–February 2020). Age-adjusted weekly mortality rates for March 2020 to December 2021 were compared with the preceding 5 years. From March 2020 to December 2021, there was an 11% excess mortality rate, corresponding to an average of 265 monthly excess deaths (maximum >30%). COVID-19-related deaths (n=3202) accounted for 54.9% of total excess deaths (n=5833) that occurred in the 22-month period. The increase in all-cause excess deaths was proportionately higher, and with significantly greater numbers, in younger age groups. Significant increases in monthly drug poisoning deaths occurred from March 2020 to April 2021, with a total of 1819 deaths. Eight hundred and 25 excess drug poisoning deaths, representing 25.4% of total all-cause excess deaths, occurred, mainly among those aged 25–60 years. Overall, 54.9% of all excess deaths were directly related to COVID-19 and 25.4% were related to drug poisoning. There was a significant increase in all-cause mortality during the COVID-19 pandemic. Although older adults are more likely to die of COVID-19, a massive increase in non-COVID-19-related mortality was observed among younger people. These factors should be considered in public policy decisions on epidemic/pandemic management.

1 September 2024 in Annals of the American Thoracic Society
Verified
Journal Article
Open access
GLGrace Lam
Grace Lam
CWChuan Wen
Chuan Wen
PRPaul E. Ronksley
Paul E. Ronksley
JBJeffrey A. Bakal
Jeffrey A. Bakal
MBMohit Bhutani
Mohit Bhutani
JWJason Weatherald
Jason Weatherald
Rationale: Existing work suggests that patients with chronic obstructive pulmonary disease (pwCOPD) presented less frequently to the emergency department and were less likely to be hospitalized during the coronavirus disease (COVID-19) pandemic, but it is unclear if this was due to improved health and disease management or to increased barriers and/or avoidance of health care. Objectives: The objective of this study was to determine the impact of the pandemic on inpatient and outpatient healthcare use, disease incidence, and mortality rates in pwCOPD. Methods: A retrospective population-based analysis using linked administrative datasets from Alberta, Canada 18 months before and after March 12, 2020 was conducted to measure hospitalization, emergency department and outpatient visits, and COPD outpatient exacerbations during these time periods. Mortality data were also analyzed before versus after the pandemic, taking confirmed COVID-19 infection within 30 days into account. Subgroup analysis based on COPD exacerbation risk stratification was undertaken to determine if healthcare use differed based on exacerbation risk. Finally, sex-based analysis of healthcare use during the pandemic was also completed. Results: Hospitalization or emergency department visits and outpatient treatment for acute exacerbations of COPD dropped, whereas total outpatient COPD visits, including both virtual and in person, increased during the pandemic for pwCOPD. The mortality rate increased even after adjusting for COVID-19–associated deaths. Sex-based subgroup analysis showed a greater drop in acute care use for females, but the rise in mortality was seen for both sexes, with men experiencing a greater rate of mortality than women. Conclusions: Overall, pwCOPD accessed acute care resources less during the pandemic, which may have contributed to a rise in non–COVID-19 all-cause mortality.


JSJesus Serrano-Lomelin
Jesus Serrano-Lomelin
CNCharlene Nielsen
Charlene Nielsen
AHAnne Hicks
Anne Hicks
SCSusan Crawford
Susan Crawford
JBJeffrey A. Bakal
Jeffrey A. Bakal
Maria B. OspinaMaria B. Ospina
Maria B. Ospina
Young children are susceptible to respiratory diseases. Inequalities exist across socioeconomic groups for paediatric respiratory health services utilization in Alberta. However, the geographic distribution of those inequalities has not been fully explored. The aim of this study was to identify geographic inequalities in respiratory health services utilization in early childhood in Calgary and Edmonton, two major urban centres in Western Canada. We conducted a geographic analysis of data from a retrospective cohort of all singleton live births occurred between 2005 and 2010. We aggregated at area-level the total number of episodes of respiratory care (hospitalizations and emergency department visits) that occurred during the first five years of life for bronchiolitis, pneumonia, lower/upper respiratory tract infections, influenza, and asthma-wheezing. We used spatial filters to identify geographic inequalities in the prevalence of acute paediatric respiratory health services utilization in Calgary and Edmonton. The average health gap between areas with the highest and the lowest prevalence of respiratory health services utilization was 1.5-fold in Calgary and 1.4-fold in Edmonton. Geographic inequalities were not completely explained by the spatial distribution of socioeconomic status, suggesting that other unmeasured factors at the neighbourhood level may explain local variability in the use of acute respiratory health services in early childhood.