A5092377709- COVID-19 Clinical Research Studies
- SARS-CoV-2 and COVID-19 Research
- SARS-CoV-2 detection and testing
- Healthcare Systems and Reforms
- COVID-19 epidemiological studies
- COVID-19 diagnosis using AI
Hamad Medical Corporation
2023-2025
Abstract Background Accurately assessing SARS-CoV-2 infection severity is essential for understanding the health impact of and evaluating effectiveness interventions. This study investigated whether SARS-CoV-2–associated hospitalizations can reliably measure true COVID-19 severity. Methods The diagnostic accuracy acute care ICU as indicators was assessed in Qatar from 6 September 2021 to 13 May 2024. WHO criteria severe, critical, fatal served reference standard. Two were assessed: (1) any...
Background SARS-CoV-2 infection is associated with protection against reinfection. This study analysed this across different reinfection symptoms and severities, comparing the preomicron omicron eras. Methods A nationwide, matched, test-negative, case–control was conducted in Qatar from 5 February 2020 to 12 March 2024. The analysis used a sample of 509 949 positive 8 494 782 negative tests, while included 682 257 6 904 044 tests. Data were sourced Qatar’s national databases for COVID-19...
Abstract Our understanding of SARS-CoV-2 reinfection patterns remains limited. We conducted a longitudinal study using Qatar’s national data from February 28, 2020 to June 11, 2023 investigate incidence reinfections both prior and after omicron emergence. The latter analysis excluded individuals with pre-omicron infections. Before introduction, the proportion incident infections classified as gradually increased but remained minimal, reaching 1.8% just before emerged. During first wave, this...
Abstract This study investigated the effectiveness of natural infection in preventing reinfection with JN.1 variant during a large wave Qatar, using test-negative case-control design. The overall previous was estimated at only 1.8% (95% CI: −9.3-12.6%). demonstrated rapid decline over time since infection, decreasing from 82.4% 40.9-94.7%) within 3 to less than 6 months after 50.9% −11.8-78.7%) subsequent months, and further dropping 18.3% −34.6-56.3%) months. Ultimately, it reached...