Framework for assessing and easing global COVID-19 travel restrictions

During the COVID-19 pandemic, many countries implemented international travel restrictions that aimed to contain viral spread while still allowing necessary cross-border travel for social and economic reasons. The relative effectiveness of these approaches for controlling the pandemic has gone largely unstudied. Here we developed a flexible network meta-population model to compare the effectiveness of international travel policies, with a focus on evaluating the benefit of policy coordination. Because country-level epidemiological parameters are unknown, they need to be estimated from data; we accomplished this using approximate Bayesian computation, given the nature of our complex stochastic disease transmission model. Based on simulation and theoretical insights we find that, under our proposed policy, international airline travel may resume up to 58% of the pre-pandemic level with pandemic control comparable to that of a complete shutdown of all airline travel. Our results demonstrate that global coordination is necessary to allow for maximum travel with minimum effect on viral spread.</p

Beating the weekend trend: Increased mortality in older adult traumatic brain injury (TBI) patients admitted on weekends

Background: Weekend admission is associated with mortality in cardiovascular emergencies and stroke but the effect of weekend admission for trauma is not well defined. We sought to determine whether differences in mortality outcomes existed for older adults with substantial head trauma admitted on a weekday versus over the weekend. Methods: Data from the 2006, 2007, and 2008 Nationwide Inpatient Sample were combined and head trauma admissions were isolated. Abbreviated injury scale (AIS) scores were calculated using ICDMAP-90 Software. Individuals aged 65 to 89 y with head AIS equal to 3 or 4 and no other region score \u3c3 were included. Individual Charlson comorbidity scores were calculated and individuals with missing mortality, sex, or insurance data were excluded. Wilcoxon rank sum and Student t-tests compared demographics, length of stay, and total charges for weekday versus weekend admissions. The χ2 tests compared sex and head injury severity. Logistic regression modeled mortality adjusting for age, sex, injury severity, comorbidity, and insurance status. Results: Of the 38,675 patients meeting criteria, 9937 (25.6%) were admitted on weekends. Mean age was similar (78.4 versus 78.4, P = 0.796) but more weekend admissions were female (51.6% versus 50.2%, P = 0.022). Weekend patients demonstrated slightly lower comorbidity (mean Charlson = 1.07 versus 1.14, P \u3c 0.001) and head injury severity (58.3% versus 60.8% AIS = 4, P \u3c 0.001). Median weekend length of stay was shorter (4 versus 5 d, P \u3c 0.001). Weekend and weekday median total charges did not differ ($27,128 versus$27,703, respectively, P = 0.667). Proportional mortality was higher among weekend patients (9.3% versus 8.4%, P = 0.008). After adjustment, weekend patients demonstrated 14% increased odds of mortality (OR 1.14, 95% CI 1.05-1.23). Conclusion: Older adults with substantial head trauma admitted on weekends are less severely injured, carry less comorbidity, and generate similar total charges compared with those admitted on weekdays. However, after accounting for known risk confounders, weekend patients demonstrated 14% greater odds of mortality. Mechanisms behind this disparity must be determined and eliminate