• The cost-effectiveness of common strategies for the prevention of transmission of SARS-CoV-2 in universities

      Zafari, Zafar; Goldman, Lee; Kovrizhkin, Katia; Muennig, Peter Alexander (Public Library of Science, 2021-09-30)
      Background: Most universities that re-open in the United States (US) for in-person instruction have implemented the Centers for Disease Prevention and Control (CDC) guidelines. The value of additional interventions to prevent the transmission of SARS-CoV-2 is unclear. We calculated the cost-effectiveness and cases averted of each intervention in combination with implementing the CDC guidelines. Methods: We built a decision-analytic model to examine the cost-effectiveness of interventions to re-open universities. The interventions included implementing the CDC guidelines alone and in combination with 1) a symptom-checking mobile application, 2) university-provided standardized, high filtration masks, 3) thermal cameras for temperature screening, 4) one-time entry ('gateway') polymerase chain reaction (PCR) testing, and 5) weekly PCR testing. We also modeled a package of interventions ('package intervention') that combines the CDC guidelines with using the symptom-checking mobile application, standardized masks, gateway PCR testing, and weekly PCR testing. The direct and indirect costs were calculated in 2020 US dollars. We also provided an online interface that allows the user to change model parameters. Results: All interventions averted cases of COVID-19. When the prevalence of actively infectious cases reached 0.1%, providing standardized, high filtration masks saved money and improved health relative to implementing the CDC guidelines alone and in combination with using the symptom-checking mobile application, thermal cameras, and gateway testing. Compared with standardized masks, weekly PCR testing cost $9.27 million (95% Credible Interval [CrI]: cost-saving-$77.36 million)/QALY gained. Compared with weekly PCR testing, the 'package' intervention cost $137,877 (95% CrI: $3,108-$19.11 million)/QALY gained. At both a prevalence of 1% and 2%, the 'package' intervention saved money and improved health compared to all the other interventions. Conclusions: All interventions were effective at averting infection from COVID-19. However, when the prevalence of actively infectious cases in the community was low, only standardized, high filtration masks clearly provided value.
    • The cost-effectiveness of standalone HEPA filtration units for the prevention of airborne SARS CoV-2 transmission.

      Zafari, Zafar; de Oliveira, Pedro M; Gkantonas, Savvas; Ezeh, Chinenye; Muennig, Peter Alexander (Springer Nature, 2022-05-12)
      Objective: Airborne infection from aerosolized SARS-CoV-2 poses an economic challenge for businesses without existing heating, ventilation, and air conditioning (HVAC) systems. The Environmental Protection Agency notes that standalone units may be used in areas without existing HVAC systems, but the cost and effectiveness of standalone units has not been evaluated. Study design: Cost-effectiveness analysis with Monte Carlo simulation and aerosol transmission modeling. Methods: We built a probabilistic decision-analytic model in a Monte Carlo simulation that examines aerosol transmission of SARS-CoV-2 in an indoor space. As a base case study, we built a model that simulated a poorly ventilated indoor 1000 square foot restaurant and the range of Covid-19 prevalence of actively infectious cases (best-case: 0.1%, base-case: 2%, and worst-case: 3%) and vaccination rates (best-case: 90%, base-case: 70%, and worst-case: 0%) in New York City. We evaluated the cost-effectiveness of improving ventilation rate to 12 air changes per hour (ACH), the equivalent of hospital-grade filtration systems used in emergency departments. We also provide a customizable online tool that allows the user to change model parameters. Results: All 3 scenarios resulted in a net cost-savings and infections averted. For the base-case scenario, improving ventilation to 12 ACH was associated with 54 [95% Credible Interval (CrI): 29-86] aerosol infections averted over 1 year, producing an estimated cost savings of $152,701 (95% CrI: $80,663, $249,501) and 1.35 (95% CrI: 0.72, 2.24) quality-adjusted life years (QALYs) gained. Conclusions: It is cost-effective to improve indoor ventilation in small businesses in older buildings that lack HVAC systems during the pandemic.
    • Decline in COPD Admissions During the COVID-19 Pandemic Associated with Lower Burden of Community Respiratory Viral Infections

      So, Jennifer Y; O'Hara, Nathan N; Kenaa, Blaine; Williams, John G; deBorja, Christopher L; Slejko, Julia F; Zafari, Zafar; Sokolow, Michael; Zimand, Paul; Deming, Meagan; et al. (Elsevier Ltd., 2021-06-12)
      Background: The COVID-19 pandemic has led to widespread implementation of public health measures, such as stay-at-home orders, social distancing, and masking mandates. In addition to decreasing spread of SARS-CoV2, these measures also impact the transmission of seasonal viral pathogens, which are common triggers of COPD exacerbations. Whether reduced viral prevalence mediates reduction in COPD exacerbation rates is unknown. Methods: We performed retrospective analysis of data from a large, multicenter healthcare system to assess admission trends associated with community viral prevalence and with initiation of COVID-19 pandemic control measures. We applied difference-in-differences (DiD) analysis to compare season-matched weekly frequency of hospital admissions for COPD before and after implementation of public health measures for COVID-19. Community viral prevalence was estimated using regional Center for Disease Control and Prevention test positivity data and correlated to COPD admissions. Results: Data involving 4,422 COPD admissions demonstrated a season-matched 53% decline in COPD admissions during COVID-19 pandemic, which correlated to community viral burden (r=0.73; 95% CI: 0.67 to 0.78) and represented a 36% greater decline over admission frequencies observed in other medical conditions less affected by respiratory viral infections (IRR, 0.64; 95% CI, 0.57 to 0.71, p<0.001). The post-COVID-19 decline in COPD admissions was most pronounced in patients with fewer comorbidities and without recurrent admissions. Conclusion: The implementation of public health measures during the COVID-19 pandemic was associated with decreased COPD admissions. These changes are plausibly explained by reduced prevalence of seasonal respiratory viruses.