Time-sensitive testing pressures and COVID-19 outcomes: are socioeconomic inequalities over the first year of the pandemic explained by selection bias?
Abstract Background There are many ways in which selection bias might impact COVID-19 research. Here we focus on selection for receiving a polymerase-chain-reaction (PCR) SARS-CoV-2 test and how known changes to selection pressures over time may bias research into COVID-19 infection. Methods Using U...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2023-09-01
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| Series: | BMC Public Health |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s12889-023-16767-5 |
| _version_ | 1797451223205412864 |
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| author | Alice R Carter Gemma L Clayton M Carolina Borges Laura D Howe Rachael A Hughes George Davey Smith Deborah A Lawlor Kate Tilling Gareth J Griffith |
| author_facet | Alice R Carter Gemma L Clayton M Carolina Borges Laura D Howe Rachael A Hughes George Davey Smith Deborah A Lawlor Kate Tilling Gareth J Griffith |
| author_sort | Alice R Carter |
| collection | DOAJ |
| description | Abstract Background There are many ways in which selection bias might impact COVID-19 research. Here we focus on selection for receiving a polymerase-chain-reaction (PCR) SARS-CoV-2 test and how known changes to selection pressures over time may bias research into COVID-19 infection. Methods Using UK Biobank (N = 420,231; 55% female; mean age = 66.8 [SD = 8·11]) we estimate the association between socio-economic position (SEP) and (i) being tested for SARS-CoV-2 infection versus not being tested (ii) testing positive for SARS-CoV-2 infection versus testing negative and (iii) testing negative for SARS-CoV-2 infection versus not being tested. We construct four distinct time-periods between March 2020 and March 2021, representing distinct periods of testing pressures and lockdown restrictions and specify both time-stratified and combined models for each outcome. We explore potential selection bias by examining associations with positive and negative control exposures. Results The association between more disadvantaged SEP and receiving a SARS-CoV-2 test attenuated over time. Compared to individuals with a degree, individuals whose highest educational qualification was a GCSE or equivalent had an OR of 1·27 (95% CI: 1·18 to 1·37) in March-May 2020 and 1·13 (95% CI: 1.·10 to 1·16) in January-March 2021. The magnitude of the association between educational attainment and testing positive for SARS-CoV-2 infection increased over the same period. For the equivalent comparison, the OR for testing positive increased from 1·25 (95% CI: 1·04 to 1·47), to 1·69 (95% CI: 1·55 to 1·83). We found little evidence of an association between control exposures, and any considered outcome. Conclusions The association between SEP and SARS-CoV-2 testing changed over time, highlighting the potential of time-specific selection pressures to bias analyses of COVID-19. Positive and negative control analyses suggest that changes in the association between SEP and SARS-CoV-2 infection over time likely reflect true increases in socioeconomic inequalities. |
| first_indexed | 2024-03-09T14:51:35Z |
| format | Article |
| id | doaj.art-bebc88621a264ddb8f00bf0f3c4057aa |
| institution | Directory Open Access Journal |
| issn | 1471-2458 |
| language | English |
| last_indexed | 2024-03-09T14:51:35Z |
| publishDate | 2023-09-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Public Health |
| spelling | doaj.art-bebc88621a264ddb8f00bf0f3c4057aa2023-11-26T14:27:29ZengBMCBMC Public Health1471-24582023-09-0123111210.1186/s12889-023-16767-5Time-sensitive testing pressures and COVID-19 outcomes: are socioeconomic inequalities over the first year of the pandemic explained by selection bias?Alice R Carter0Gemma L Clayton1M Carolina Borges2Laura D Howe3Rachael A Hughes4George Davey Smith5Deborah A Lawlor6Kate Tilling7Gareth J Griffith8MRC Integrative Epidemiology Unit, University of BristolMRC Integrative Epidemiology Unit, University of BristolMRC Integrative Epidemiology Unit, University of BristolMRC Integrative Epidemiology Unit, University of BristolMRC Integrative Epidemiology Unit, University of BristolMRC Integrative Epidemiology Unit, University of BristolMRC Integrative Epidemiology Unit, University of BristolMRC Integrative Epidemiology Unit, University of BristolMRC Integrative Epidemiology Unit, University of BristolAbstract Background There are many ways in which selection bias might impact COVID-19 research. Here we focus on selection for receiving a polymerase-chain-reaction (PCR) SARS-CoV-2 test and how known changes to selection pressures over time may bias research into COVID-19 infection. Methods Using UK Biobank (N = 420,231; 55% female; mean age = 66.8 [SD = 8·11]) we estimate the association between socio-economic position (SEP) and (i) being tested for SARS-CoV-2 infection versus not being tested (ii) testing positive for SARS-CoV-2 infection versus testing negative and (iii) testing negative for SARS-CoV-2 infection versus not being tested. We construct four distinct time-periods between March 2020 and March 2021, representing distinct periods of testing pressures and lockdown restrictions and specify both time-stratified and combined models for each outcome. We explore potential selection bias by examining associations with positive and negative control exposures. Results The association between more disadvantaged SEP and receiving a SARS-CoV-2 test attenuated over time. Compared to individuals with a degree, individuals whose highest educational qualification was a GCSE or equivalent had an OR of 1·27 (95% CI: 1·18 to 1·37) in March-May 2020 and 1·13 (95% CI: 1.·10 to 1·16) in January-March 2021. The magnitude of the association between educational attainment and testing positive for SARS-CoV-2 infection increased over the same period. For the equivalent comparison, the OR for testing positive increased from 1·25 (95% CI: 1·04 to 1·47), to 1·69 (95% CI: 1·55 to 1·83). We found little evidence of an association between control exposures, and any considered outcome. Conclusions The association between SEP and SARS-CoV-2 testing changed over time, highlighting the potential of time-specific selection pressures to bias analyses of COVID-19. Positive and negative control analyses suggest that changes in the association between SEP and SARS-CoV-2 infection over time likely reflect true increases in socioeconomic inequalities.https://doi.org/10.1186/s12889-023-16767-5Health inequalitiesSelection biasCOVID-19Socioeconomic positionLinkage studies |
| spellingShingle | Alice R Carter Gemma L Clayton M Carolina Borges Laura D Howe Rachael A Hughes George Davey Smith Deborah A Lawlor Kate Tilling Gareth J Griffith Time-sensitive testing pressures and COVID-19 outcomes: are socioeconomic inequalities over the first year of the pandemic explained by selection bias? BMC Public Health Health inequalities Selection bias COVID-19 Socioeconomic position Linkage studies |
| title | Time-sensitive testing pressures and COVID-19 outcomes: are socioeconomic inequalities over the first year of the pandemic explained by selection bias? |
| title_full | Time-sensitive testing pressures and COVID-19 outcomes: are socioeconomic inequalities over the first year of the pandemic explained by selection bias? |
| title_fullStr | Time-sensitive testing pressures and COVID-19 outcomes: are socioeconomic inequalities over the first year of the pandemic explained by selection bias? |
| title_full_unstemmed | Time-sensitive testing pressures and COVID-19 outcomes: are socioeconomic inequalities over the first year of the pandemic explained by selection bias? |
| title_short | Time-sensitive testing pressures and COVID-19 outcomes: are socioeconomic inequalities over the first year of the pandemic explained by selection bias? |
| title_sort | time sensitive testing pressures and covid 19 outcomes are socioeconomic inequalities over the first year of the pandemic explained by selection bias |
| topic | Health inequalities Selection bias COVID-19 Socioeconomic position Linkage studies |
| url | https://doi.org/10.1186/s12889-023-16767-5 |
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