Pedestrian Deaths During the COVID-19 Pandemic.

The COVID pandemic provides a natural experiment examining how a 50-60% reduction in pedestrian activity might lead to a reduction in pedestrian deaths. We assessed whether the reduction in pedestrian deaths was proportional to a one-to-one matching presumed in statistics correlating mobility with fatality. The primary analysis examined New York (largest city in US), and the validation analysis examined Toronto (largest city in Canada). We identified pedestrian activity in each location from the Apple Mobility database, normalized to the baseline in January 2020. We calculated monthly pedestrian deaths from the Vision Zero database in each city with baseline data from 3 prior years. We found a large initial reduction in pedestrian deaths during the lockdown in New York that was transient and not statistically significant during the summer and autumn despite sustained reductions in pedestrian activity. Similarly, we found a large initial reduction in pedestrian deaths during the lockdown in Toronto that was transient and not sustained. Together, these data suggest the substantial reductions in pedestrian activity during the COVID pandemic have no simple correlation with pedestrian fatality counts in the same locations. An awareness of this finding emphasizes the role of unmeasured modifiable individual factors beyond pedestrian infrastructure or other structural contributors.

Effect of Ward-Based High-Flow Nasal Cannula (HFNC) Oxygen Therapy on Critical Care Utilization During the COVID-19 Pandemic: A Retrospective Cohort Analysis.

BACKGROUND: Hospitals expanded critical care capacity during the COVID-19 pandemic by treating COVID-19 patients with high-flow nasal cannula oxygen therapy (HFNC) in non-traditional settings, including general internal medicine (GIM) wards. The impact of this practice on intensive care unit (ICU) capacity is unknown. OBJECTIVE: To describe how our hospital operationalized the use of HFNC on GIM wards, assess its impact on ICU capacity, and examine the characteristics and outcomes of treated patients. DESIGN: Retrospective cohort study of all patients treated with HFNC on GIM wards at a Canadian tertiary care hospital. PARTICIPANTS: All patients admitted with COVID-19 and treated with HFNC on GIM wards from December 28, 2020, to June 13, 2021, were included. MAIN MEASURES: We combined administrative data on critical care occupancy daily with chart-abstracted data for included patients to establish the total number of patients receiving ICU-level care at our hospital per day. We also collected data on demographics, medical comorbidities, illness severity, COVID-19 treatments, HFNC care processes, and patient outcomes. KEY RESULTS: We treated 124 patients with HFNC on the GIM wards (median age 66 years; 48% female). Patients were treated with HFNC for a median of 5 days (IQR 3 to 8); collectively, they received HFNC for a total of 740 hospital days, 71% of which were on GIM wards. At peak ICU capacity strain (144%), delivering HFNC on GIM wards added 20% to overall ICU capacity by managing up to 14 patients per day. Patients required a median maximal fraction of inspired oxygen of 80% (IQR 60 to 95). There were 18 deaths (15%) and 85 patients (69%) required critical care admission; of those, 40 (47%) required mechanical ventilation. CONCLUSIONS: With appropriate training and resources, treatment of COVID-19 patients with HFNC on GIM wards appears to be a feasible strategy to increase critical care capacity.

Good things come in threes (and sometimes fours): Update on renin–angiotensin–aldosterone system inhibitors and COVID-19: CMAJ

Quinn et al examine the role of renin-angiotensin-aldosterone system (RAAS) inhibitors in patients with coronavirus disease 2019 (COVID-19). Three large observational studies of more than 20,000 patients with COVID-19 found no association between the use of RAAS inhibitors and increased risk of infection, development of severe disease or death. The 3 studies used different methodological approaches, and all came to similar conclusions. A different cohort study of 18,472 patients who were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) also found no association between RAAS inhibitor use and testing positive for COVID-19. However, a secondary analysis of 1,735 patients in the study with confirmed COVID-19 showed an increased risk of severe disease requiring admission to the intensive care unit in patients using RAAS inhibitors. All observational studies are at risk of unmeasured confounding. However, according to the results across these studies, RAAS inhibitors are unlikely to cause harm in patients with COVID-19.