Examining SARS-CoV-2 Interventions in Residential Colleges Using an Empirical Network.

Objectives Universities have turned to SARS-CoV-2 models to examine campus reopening strategies. While these studies have explored a variety of modeling techniques, none have used empirical data. Methods In this study, we use an empirical proximity network of college freshmen obtained using smartphone Bluetooth to simulate the spread of the virus. We investigate the role of immunization, testing, isolation, mask wearing, and social distancing in the presence of implementation challenges and imperfect compliance. Results We show that frequent testing could drastically reduce the spread of the virus if levels of immunity are low, but its effects are limited if immunity is more ubiquitous. Furthermore, moderate levels of mask wearing and social distancing could lead to additional reductions in cumulative incidence, but their benefit decreases rapidly as immunity and testing frequency increase. However, if immunity from vaccination is imperfect or declines over time, scenarios not studied here, frequent testing and other interventions may play more central roles. Conclusions Our findings suggest that although regular testing and isolation are powerful tools, they have limited benefit if immunity is high or other interventions are widely adopted. If universities can attain even moderate levels of vaccination, masking, and social distancing, they may be able to relax the frequency of testing to once every four weeks.

Examining SARS-CoV-2 Interventions in Residential Colleges Using an Empirical Network.

Universities have turned to SARS-CoV-2 models to examine campus reopening strategies1-9. While these studies have explored a variety of modeling techniques, all have relied on simulated data. Here, we use an empirical proximity network of college freshmen10, ascertained using smartphone Bluetooth, to simulate the spread of the virus. We investigate the role of testing, isolation, mask wearing, and social distancing in the presence of implementation challenges and imperfect compliance. Here we show that while frequent testing can drastically reduce spread if mask wearing and social distancing are not widely adopted, testing has limited impact if they are ubiquitous. Furthermore, even moderate levels of immunity can significantly reduce new infections, especially when combined with other interventions. Our findings suggest that while testing and isolation are powerful tools, they have limited benefit if other interventions are widely adopted. If universities can attain high levels of masking and social distancing, they may be able to relax testing frequency to once every two to four weeks.

Functional recovery after moderate/severe traumatic brain injury: a role for cognitive reserve?

OBJECTIVE: To evaluate the hypothesis that educational attainment, a marker of cognitive reserve, is a predictor of disability-free recovery (DFR) after moderate to severe traumatic brain injury (TBI). METHODS: Retrospective study of the TBI Model Systems Database, a prospective multicenter cohort funded by the National Institute on Disability and Rehabilitation Research. Patients were included if they were admitted for rehabilitation after moderate to severe TBI, were aged 23 years or older, and had at least 1 year of follow-up. The main outcome measure was DFR 1 year postinjury, defined as a Disability Rating Scale score of zero. RESULTS: Of 769 patients included, 214 (27.8%) achieved DFR at 1 year. In total, 185 patients (24.1%) had <12 years of education, while 390 (50.7%) and 194 patients (25.2%) had 12 to 15 years and ≥16 years of education, respectively. DFR was achieved by 18 patients (9.7%) with <12 years, 120 (30.8%) with 12 to 15 years, and 76 (39.2%) with ≥16 years of education (p < 0.001). In a logistic regression model controlling for age, sex, and injury- and rehabilitation-specific factors, duration of education of ≥12 years was independently associated with DFR (odds ratio 4.74, 95% confidence interval 2.70-8.32 for 12-15 years; odds ratio 7.24, 95% confidence interval 3.96-13.23 for ≥16 years). CONCLUSION: Educational attainment was a robust independent predictor of 1-year DFR even when adjusting for other prognostic factors. A dose-response relationship was noted, with longer educational exposure associated with increased odds of DFR. This suggests that cognitive reserve could be a factor driving neural adaptation during recovery from TBI.

Falling temperature and colder weather are associated with an increased risk of aneurysmal subarachnoid hemorrhage.

OBJECTIVE: To use weather data to predict increased incidence of aneurysmal subarachnoid hemorrhage (aSAH) at a large institution with an extensive referral network in response to falling temperatures. METHODS: In a retrospective study, 1175 prospectively collected aSAH cases accrued over 18 years from one hospital were reviewed to determine if season, maximum ambient temperature (MAT), average relative humidity, and atmospheric pressure were related to incidence of aSAH at that institution on a given day. A Poisson regression model was used to assess daily risk of incident aSAH based on daily MAT and 1-day change in MAT. RESULTS: A MAT decrease of 1°F from one day to the next was associated with a 0.6% increase in risk of aSAH (relative risk [RR]=1.006, P=0.016). The increased risk associated with MAT decrease from the previous day was especially strong for female patients (RR=1.008/°F, P=0.007) and drove the overall model, representing 72% of cases. In addition, warmer temperatures were associated with a decreased risk of aSAH; each 1°F increase in temperature compared with the previous day was associated with a 0.3% decrease in risk of aSAH (RR=0.997; P<0.001). CONCLUSIONS: A 1-day decrease in temperature and colder daily temperatures were associated with an increased risk of incident aSAH at a single institution with a large referral network. These variables appeared to act synergistically and independently of season. These relationships were particularly predominant in the fall when the transition from warmer to colder temperatures occurred.

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 <3 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 < 0.001) and head injury severity (58.3% versus 60.8% AIS = 4, P < 0.001). Median weekend length of stay was shorter (4 versus 5 d, P < 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 eliminated.

The impact of race and ethnicity on the outcome of carotid interventions in the United States.

OBJECTIVE: Previous studies have demonstrated an adverse impact of African American race and Hispanic ethnicity on the outcomes of carotid endarterectomy (CEA), although little is known about the influence of race and ethnicity on the outcome of carotid angioplasty and stenting (CAS). The present study was undertaken to examine the influence of race and ethnicity on the outcomes of CEA and CAS in contemporary practice. METHODS: The nationwide inpatient sample (2005-2008) was queried using International Classification of Diseases-9 codes for CEA and CAS in patients with carotid artery stenosis. The primary outcomes were postoperative death or stroke. Multivariate analysis was performed adjusting for age, gender, race, comorbidities, high-risk status, procedure type, symptomatic status, year, insurance type, and hospital characteristics. RESULTS: Overall, there were 347,450 CEAs and 47,385 CASs performed in the United States over the study period. After CEA, Hispanics had the greatest risk of mortality (P < 0.001), whereas black patients had the greatest risk of stroke (P = 0.02) compared with white patients on univariate analysis. On multivariable analysis, Hispanic ethnicity remained an independent risk factor for mortality after CEA (relative risk 2.40; P < 0.001), whereas the increased risk of stroke in black patients was no longer significant. After CAS, there were no racial or ethnic differences in mortality. On univariate analysis, the risk of stroke was greatest in black patients after CAS (P = 0.03). However, this was not significant on multivariable analysis. CONCLUSION: Hispanic ethnicity is an independent risk factor for mortality after CEA. While black patients had an increased risk of stroke after CEA and CAS, this was explained by factors other than race. Further studies are warranted to determine if Hispanic ethnicity remains an independent risk factor for mortality after discharge.

Differential association of race with treatment and outcomes in Medicare patients undergoing diverticulitis surgery.

BACKGROUND: Observed racial disparities in diverticulitis surgery have been attributed to differences in health insurance status and medical comorbidity. OBJECTIVE: To examine disparities in procedure type (elective vs urgent/emergency) and mortality in patients with surgically treated diverticulitis insured by Medicare, accounting for comorbidities. DESIGN: Retrospective analysis of Medicare Provider Analysis and Review inpatient data. PATIENTS: All blacks and whites 65 years and older undergoing surgical treatment for primary diverticulitis with complete admission and outcome data were eligible. MAIN OUTCOME MEASURES: In-hospital mortality was examined across procedure categories (elective vs urgent/emergency). Multivariable regression controlled for age, sex, and medical comorbidity (Charlson Comorbidity Index). RESULTS: A total of 49 937 whites and 2283 blacks met the study criteria. Blacks were slightly younger (74.7 vs 75.5 years, P < .001) and more likely to be female (75.2% vs 69.8%, P < .001). Blacks carried greater comorbidity than did whites (mean Charlson Comorbidity Index score: 0.98 vs 0.87, P < .001); 67.8% of blacks vs 54.7% of whites (P < .001) were urgent/emergency. After adjustment, blacks demonstrated 26% greater risk of urgent/emergency admission (relative risk, 1.26; 95% CI, 1.22-1.30). Black race was also associated with a 28% greater risk of mortality (relative risk, 1.28; 95% CI, 1.10-1.51). CONCLUSIONS: Blacks underwent urgent/emergency surgery more often than did whites. Blacks demonstrated significantly increased mortality risk after controlling for age, sex, and comorbidities. These findings suggest that observed racial disparities encompass more than just insurance status and medical comorbidity. Mechanisms leading to worse outcomes for blacks must be elucidated.