ABSTRACT
Background: Social distancing measures introduced during the COVID-19 pandemic have reduced admission rates for a variety of respiratory tract infections. We hypothesized that rates of asthma exacerbations would decline following the national lockdown introduced on March 12, 2020, in Denmark. Aim(s): To determine weekly rates of in- and out of hospital asthma exacerbations prior to and during the national lockdown. Method(s): All persons >18 years with at least one outpatient hospital contact with asthma as the primary diagnosis from January 1, 2013, to December 31, 2017, were included. Weekly asthma exacerbation rates from January 1, 2018, to May 22, 2020, were assessed. An interrupted time-series (ITS model) with March 12, 2020, as the point of interruption was conducted. Result(s): A total of 38,225 patients with asthma were identified. The ITS model showed no immediate changes in exacerbation rates during the first week after March 12, 2020. However, there was a significant decrease in weekly exacerbation rates in the following 10 weeks (change in trend for exacerbations requiring hospitalisation: -0.75 [95% CI -1.39,-0.12], (p < 0.02) corresponding to a reduction of about 1 exacerbation per year per 100 patients in the cohort, and a change in trend for all asthma exacerbations: -12.2 [95% CI -19.1,-5.4], p<0.001 corresponding to a reduction of 16.5 exacerbations per year per 100 patients in the cohort). Conclusion(s): The introduction of the social distancing measures in Denmark on March 12, 2020, did not lead to an immediate reduction in asthma exacerbation rates, however a gradual decline in exacerbation rates during the following 10-weeks period was observed.
ABSTRACT
INTRODUCTION: Fast and accurate detection of SARS-CoV-2 is essential in limiting the COVID-19 pandemic. Rapid antigen (AG) tests provide results within minutes;however, their accuracy has been questioned. The study aims to determine the accuracy and cost of the STANDARD Q COVID-19 AG test compared with RT-PCR. METHODS: Individuals 18 years or older with an appointment for a RT-PCR test on 26-31 December 2020 at a public test centre in Copenhagen, Denmark were invited to participate. An oropharyngeal swab was collected for RT-PCR analysis, followed by a nasopharyngeal swab examined by the AG test (SD Biosensor). The diagnostic accuracy of the AG test was calculated with RT-PCR as reference. Costs were evaluated for both tests. RESULTS: A total of 4,811 paired conclusive test results were collected (median age: 45 years, female: 53%). The RT-PCR test revealed 221 (4.6%) positive tests. The overall sensitivity and specificity of the AG test were 69.7% and 99.5%, respectively. Viral cycle threshold values were significantly higher in individuals with false negative AG tests than in individuals who were true positives. The RT-PCR test and AG test costs were 67.0 DKK (10.8 USD) and 35.0 DKK (5.7 USD), respectively, per positive case detected at 100,000 daily tests. CONCLUSIONS: The AG test enables mass testing and provides immediate results, which is important in SARS-CoV-2 screening. The AG test is a good and relevant supplement to RT-PCR testing in public SARS-CoV-2 screenings. FUNDING: This project received no external funding. Copenhagen Medical A/S delivering the rapid AG tests and provided test personnel but were not otherwise involved. TRIAL REGISTRATION: Clinicaltrials.org: NCT04716088.