Risk factors for SARS-CoV-2 infection: a test-negative case–control study with additional population controls in Norway
Objectives This study aims to assess risk factors for SARS-CoV-2 infection by combined design; first comparing positive cases to negative controls as determined by PCR testing and then comparing these two groups to an additional prepandemic population control group.Design and setting Test-negative d...
| Main Authors: | , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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BMJ Publishing Group
2024-01-01
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| Series: | BMJ Open |
| Online Access: | https://bmjopen.bmj.com/content/14/1/e073766.full |
| _version_ | 1797361635412672512 |
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| author | Neil Pearce Svein Arne Nordbø Chi Zhang Anne Kristin Moeller Fell Johny Kongerud Yngvar Tveten Jan Vandenbroucke Randi Eikeland Harald Reiso Marjut Sarjomaa Hege Kersten Kristine Karlsrud Berg Carina Thilesen Ingeborg S Aaberge |
| author_facet | Neil Pearce Svein Arne Nordbø Chi Zhang Anne Kristin Moeller Fell Johny Kongerud Yngvar Tveten Jan Vandenbroucke Randi Eikeland Harald Reiso Marjut Sarjomaa Hege Kersten Kristine Karlsrud Berg Carina Thilesen Ingeborg S Aaberge |
| author_sort | Neil Pearce |
| collection | DOAJ |
| description | Objectives This study aims to assess risk factors for SARS-CoV-2 infection by combined design; first comparing positive cases to negative controls as determined by PCR testing and then comparing these two groups to an additional prepandemic population control group.Design and setting Test-negative design (TND), multicentre case–control study with additional population controls in South-Eastern Norway.Participants Adults who underwent SARS-CoV-2 PCR testing between February and December 2020. PCR-positive cases, PCR-negative controls and additional age-matched population controls.Primary outcome measures The associations between various risk factors based on self- reported questionnaire and SARS-CoV-2 infection comparing PCR-positive cases and PCR-negative controls. Using subgroup analysis, the risk factors for both PCR-positive and PCR-negative participants were compared with a population control group.Results In total, 400 PCR-positive cases, 719 PCR-negative controls and 14 509 population controls were included. Male sex was associated with the risk of SARS-CoV-2 infection only in the TND study (OR 1.9, 95% CI 1.4 to 2.6), but not when PCR-positive cases were compared with population controls (OR 1.2, 95% CI 0.9. to 1.5). Some factors were positively (asthma, wood heating) or negatively (hypertension) associated with SARS-CoV-2 infection when PCR-positive cases were compared with population controls, but lacked convincing association in the TND study. Smoking was negatively associated with the risk of SARS-CoV-2 infection in both analyses (OR 0.5, 95% CI 0.3 to 0.8 and OR 0.6, 95% CI 0.4 to 0.8).Conclusions Male sex was a possible risk factor for SARS-CoV-2 infection only in the TND study, whereas smoking was negatively associated with SARS-CoV-2 infection in both the TND study and when using population controls. Several factors were associated with SARS-CoV-2 infection when PCR-positive cases were compared with population controls, but not in the TND study, highlighting the strength of combining case–control study designs during the pandemic. |
| first_indexed | 2024-03-08T15:56:28Z |
| format | Article |
| id | doaj.art-5c574b81151b41b89111ded0b1c6cfb7 |
| institution | Directory Open Access Journal |
| issn | 2044-6055 |
| language | English |
| last_indexed | 2024-03-08T15:56:28Z |
| publishDate | 2024-01-01 |
| publisher | BMJ Publishing Group |
| record_format | Article |
| series | BMJ Open |
| spelling | doaj.art-5c574b81151b41b89111ded0b1c6cfb72024-01-08T20:05:09ZengBMJ Publishing GroupBMJ Open2044-60552024-01-0114110.1136/bmjopen-2023-073766Risk factors for SARS-CoV-2 infection: a test-negative case–control study with additional population controls in NorwayNeil Pearce0Svein Arne Nordbø1Chi Zhang2Anne Kristin Moeller Fell3Johny Kongerud4Yngvar Tveten5Jan Vandenbroucke6Randi Eikeland7Harald Reiso8Marjut Sarjomaa9Hege Kersten10Kristine Karlsrud Berg11Carina Thilesen12Ingeborg S Aaberge13Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, UKNorwegian University of Science and Technology, Department of Clinical and Molecular Medicine, Trondheim, NorwayNorwegian Institute of Public Health, Oslo, NorwayOccupational and Environmental Medicine, Sykehuset Telemark HF, Skien, NorwayInstitute of Clinical Medicine, University of Oslo Faculty of Medicine, Oslo, NorwayA/S Telelab, Telemark Biomedical Centre, PO Box 1868 Gulset, N-3705 Skien, Norwayprofessor of clinical epidemiology10 Institute of Health and Nursing Science, University of Agder, Kristiansand, NorwayThe Norwegian National Advisory Unit on Tick-borne diseases, Sørlandet sykehus HF Arendal, Arendal, NorwayInfection Control, Telemark Hospital, Skien, NorwayDepartment of Research, Telemark Hospital, Skien, NorwayDepartment of Medical Microbiology, Sørlandet Sykehus HF, Kristiansand, NorwayUnilabs Laboratory Medicine, Skien, NorwayNorwegian Institute of Public Health, Oslo, NorwayObjectives This study aims to assess risk factors for SARS-CoV-2 infection by combined design; first comparing positive cases to negative controls as determined by PCR testing and then comparing these two groups to an additional prepandemic population control group.Design and setting Test-negative design (TND), multicentre case–control study with additional population controls in South-Eastern Norway.Participants Adults who underwent SARS-CoV-2 PCR testing between February and December 2020. PCR-positive cases, PCR-negative controls and additional age-matched population controls.Primary outcome measures The associations between various risk factors based on self- reported questionnaire and SARS-CoV-2 infection comparing PCR-positive cases and PCR-negative controls. Using subgroup analysis, the risk factors for both PCR-positive and PCR-negative participants were compared with a population control group.Results In total, 400 PCR-positive cases, 719 PCR-negative controls and 14 509 population controls were included. Male sex was associated with the risk of SARS-CoV-2 infection only in the TND study (OR 1.9, 95% CI 1.4 to 2.6), but not when PCR-positive cases were compared with population controls (OR 1.2, 95% CI 0.9. to 1.5). Some factors were positively (asthma, wood heating) or negatively (hypertension) associated with SARS-CoV-2 infection when PCR-positive cases were compared with population controls, but lacked convincing association in the TND study. Smoking was negatively associated with the risk of SARS-CoV-2 infection in both analyses (OR 0.5, 95% CI 0.3 to 0.8 and OR 0.6, 95% CI 0.4 to 0.8).Conclusions Male sex was a possible risk factor for SARS-CoV-2 infection only in the TND study, whereas smoking was negatively associated with SARS-CoV-2 infection in both the TND study and when using population controls. Several factors were associated with SARS-CoV-2 infection when PCR-positive cases were compared with population controls, but not in the TND study, highlighting the strength of combining case–control study designs during the pandemic.https://bmjopen.bmj.com/content/14/1/e073766.full |
| spellingShingle | Neil Pearce Svein Arne Nordbø Chi Zhang Anne Kristin Moeller Fell Johny Kongerud Yngvar Tveten Jan Vandenbroucke Randi Eikeland Harald Reiso Marjut Sarjomaa Hege Kersten Kristine Karlsrud Berg Carina Thilesen Ingeborg S Aaberge Risk factors for SARS-CoV-2 infection: a test-negative case–control study with additional population controls in Norway BMJ Open |
| title | Risk factors for SARS-CoV-2 infection: a test-negative case–control study with additional population controls in Norway |
| title_full | Risk factors for SARS-CoV-2 infection: a test-negative case–control study with additional population controls in Norway |
| title_fullStr | Risk factors for SARS-CoV-2 infection: a test-negative case–control study with additional population controls in Norway |
| title_full_unstemmed | Risk factors for SARS-CoV-2 infection: a test-negative case–control study with additional population controls in Norway |
| title_short | Risk factors for SARS-CoV-2 infection: a test-negative case–control study with additional population controls in Norway |
| title_sort | risk factors for sars cov 2 infection a test negative case control study with additional population controls in norway |
| url | https://bmjopen.bmj.com/content/14/1/e073766.full |
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