Associations between negative COVID-19 experiences and symptoms of anxiety and depression: a study based on a representative Canadian national sample. / Associations entre les expériences négatives liées à la COVID-19 et les symptômes d'anxiété et de dépression : étude fondée sur un échantillon national canadien représentatif.

INTRODUCTION: Amid the widespread impact of the COVID-19 pandemic, a notable increase in symptoms of anxiety and depression has become a pressing concern. This study examined the prevalence of anxiety and depression symptoms in Canada from September to December 2020, assessing demographic and socioeconomic influences, as well as the potential role of COVID-19 diagnoses and related negative experiences. METHODS: Data were drawn from the Survey on COVID-19 and Mental Health by Statistics Canada, which used a two-stage sample design to gather responses from 14 689 adults across ten provinces and three territorial capitals, excluding less than 2% of the population. Data were collected through self-administered electronic questionnaires or phone interviews. Analytical techniques, such as frequencies, cross-tabulation and logistic regression, were used to assess the prevalence of anxiety and depression symptoms, the demographic characteristics of Canadians with increased anxiety and depression symptoms and the association of these symptoms with COVID-19 diagnoses and negative experiences during the pandemic. RESULTS: The study found that 14.62% (95% CI: 13.72%-15.51%) of respondents exhibited symptoms of depression, while 12.89% (95% CI: 12.04%-13.74%) reported anxiety symptoms. No clear differences in symptom prevalence were observed between those infected by COVID-19, or those close to someone infected, compared to those without these experiences. However, there were strong associations between traditional risk factors for depressive and anxiety symptoms and negative experiences during the pandemic, such as physical health problems, loneliness and personal relationship challenges in the household. CONCLUSION: This study provides insight into the relationship between COVID-19 and Canadians' mental health, demonstrating an increased prevalence of anxiety and depression symptoms associated with COVID-19-related adversities and common prepandemic determinants of these symptoms. The findings suggest that mental health during the pandemic was primarily shaped by traditional determinants of depression and anxiety symptoms and also by negative experiences during the pandemic.

Trends in vaping and smoking behavior before and during the COVID-19 pandemic in Canada: Beneficial and potentially detrimental changes.

INTRODUCTION: E-cigarette and cigarette use may have changed during the COVID-19 pandemic, however, there is no consensus in existing literature, and current Canadian studies have not used representative samples. Thus, there is a need for robust national estimates. OBJECTIVE AND METHODS: The primary objective was to describe the 30-day period prevalence of smoking and vaping before and during the COVID-19 pandemic in Canada. This study analyzed three years of the cross-sectional Canadian Tobacco and Nicotine Survey: 2019 (pre-pandemic), 2020 (9 months into the pandemic) and 2021 (21 months into pandemic). RESULTS: Thirty-day period prevalence of vaping over the 2019, 2020, and 2021 study periods were 4.8 (95%CI: 4.2-5.3), 4.6% (95%CI: 4.1-5.2), and 5.2% (95%CI: 4.7-5.7), respectively. The 30-day period prevalence of smoking over the 2019, 2020, and 2021 study periods were 11.9% (95%CI: 10.9-12.7), 10.3% (95%CI: 9.4-11.2), and 10.3% (95%CI: 9.4-11.1), respectively. Notably, estimates of smoking for females decreased considerably from 2019 (11.0%; 95%CI: 9.9--12.2%) to 2020 (8.6%; 95%CI: 7.5-9.7). Estimates of vaping in those aged 20-24 increased substantially from 2020 (13.0%; 95%CI: 10.9-15.1) to 2021 (17.2%; 95%CI: 15.4-18.9). CONCLUSIONS: Changes to smoking and vaping were restricted to subsets within the population. In those aged 20-24, there was a modest increase in vaping from 2020 to 2021. In females, there was a decrease in smoking from 2019 to 2020, which persisted in 2021.

Adherence to a lower versus higher intensity physical activity intervention in the Breast Cancer & Physical Activity Level (BC-PAL) Trial.

PURPOSE: The first aim is to examine adherence to a lower versus higher intensity physical activity (PA) prescription in breast cancer survivors in the Breast Cancer & Physical Activity Level (BC-PAL) Trial. The second aim is to assess associations between baseline characteristics with mean PA adherence in both intervention groups combined. METHODS: Forty-five participants were randomized to a 12-week, home-based lower (300 min/week, 40-59% heart rate reserve (HRR)) or higher (150 min/week, 60-80% HRR) intensity PA intervention, or no intervention/control. Both intervention groups received Polar A360® trackers and were included in this analysis (n=30). Study outcomes assessed on a weekly basis with the Polar A360® activity tracker throughout the intervention included relative adherence to the prescribed PA interventions (% of PA prescription goal met), and the absolute amount of PA time ≥40% of HRR. Baseline predictors of adherence included demographic characteristics, cardiorespiratory fitness, habitual PA and sedentary time, quality of life measures, and motivational variables from the Theory of Planned Behavior. For our primary aim, a linear mixed model was used to assess the effects of randomization group, time (intervention weeks 1-12), and the interaction of these factors on the natural logarithm of PA adherence. For our secondary aim, the association between each baseline predictor with the natural logarithm of mean weekly PA adherence was assessed, with randomization group added as a covariate. RESULTS: Higher relative time within the prescribed HRR zone was noted in the lower versus higher intensity PA groups (eß=3.12, 95% CI=1.97, 4.95). No differences in adherence across time were noted. Social support was inversely associated with relative PA time within the prescribed HRR zone (eß=0.83, 95% CI=0.72, 0.97) and absolute PA time ≥40% of HRR (eß= 0.82, 95% CI: 0.71, 0.93). Baseline VO2max was inversely associated with relative PA adherence (eß=0.98, 95% CI=0.95, 0.99). No other baseline measures were associated with PA adherence. CONCLUSIONS: There were no significant changes in absolute PA time ≥40% of HRR across time or between groups. However, the lower intensity PA group averaged over 3 times the relative amount of PA within the prescribed HRR zone compared to the higher intensity PA group. Finally, lower peer support and cardiorespiratory fitness at baseline were associated with higher PA adherence. IMPLICATIONS FOR CANCER SURVIVORS: The recent rise in popularity of commercially available activity trackers provides new opportunities to promote PA participation remotely, and these devices can be used to continuously and objectively measure PA levels as an indicator of intervention adherence. Future studies are needed to explore baseline predictors, facilitators, and barriers to sustained activity tracker use to promote PA behavior change and intervention adherence in cancer survivors. TRIAL REGISTRATION: This study was registered at www. CLINICALTRIALS: gov (No. NCT03564899) on June 21, 2018.

Validation of an improved method to calculate the orientation and magnitude of pedicle screw bending moments.

Previous methods of pedicle screw strain measurement have utilized complex, time consuming methods of strain gauge application, experience high failure rates, do not effectively measure resultant bending moments, and cannot predict moment orientation. The purpose of this biomechanical study was to validate an improved method of quantifying pedicle screw bending moment orientation and magnitude. Pedicle screws were instrumented to measure biplanar screw bending moments by positioning four strain gauges on flat, machined surfaces below the screw head. Screws were calibrated to measure bending moments by hanging certified weights a known distance from the strain gauges. Loads were applied in 30 deg increments at 12 different angles while recording data from two independent strain channels. The data were then analyzed to calculate the predicted orientation and magnitude of the resultant bending moment. Finally, flexibility tests were performed on a cadaveric motion segment implanted with the instrumented screws to demonstrate the implementation of this technique. The difference between the applied and calculated orientation of the bending moments averaged (±standard error of the mean (SEM)) 0.3 ± 0.1 deg across the four screws for all rotations and loading conditions. The calculated resultant bending moments deviated from the actual magnitudes by an average of 0.00 ± 0.00 Nm for all loading conditions. During cadaveric testing, the bending moment orientations were medial/lateral in flexion-extension, variable in lateral bending, and diagonal in axial torsion. The technique developed in this study provides an accurate method of calculating the orientation and magnitude of screw bending moments and can be utilized with any pedicle screw fixation system.