Preventing bias from selective non-response in population-based survey studies: findings from a Monte Carlo simulation study
Abstract Background Health researchers often use survey studies to examine associations between risk factors at one time point and health outcomes later in life. Previous studies have shown that missing not at random (MNAR) may produce biased estimates in such studies. Medical researchers typically...
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| Format: | Article |
| Language: | English |
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BMC
2019-06-01
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| Series: | BMC Medical Research Methodology |
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| Online Access: | http://link.springer.com/article/10.1186/s12874-019-0757-1 |
| _version_ | 1819208870428409856 |
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| author | Kristin Gustavson Espen Røysamb Ingrid Borren |
| author_facet | Kristin Gustavson Espen Røysamb Ingrid Borren |
| author_sort | Kristin Gustavson |
| collection | DOAJ |
| description | Abstract Background Health researchers often use survey studies to examine associations between risk factors at one time point and health outcomes later in life. Previous studies have shown that missing not at random (MNAR) may produce biased estimates in such studies. Medical researchers typically do not employ statistical methods for treating MNAR. Hence, there is a need to increase knowledge about how to prevent occurrence of such bias in the first place. Methods Monte Carlo simulations were used to examine the degree to which selective non-response leads to biased estimates of associations between risk factors and health outcomes when persons with the highest levels of health problems are under-represented or totally missing from the sample. This was examined under different response rates and different degrees of dependency between non-response and study variables. Results Response rate per se had little effect on bias. When extreme values on the health outcome were completely missing, rather than under-represented, results were heavily biased even at a 70% response rate. In most situations, 50–100% of this bias could be prevented by including some persons with extreme scores on the health outcome in the sample, even when these persons were under-represented. When some extreme scores were present, estimates of associations were unbiased in several situations, only mildly biased in other situations, and became biased only when non-response was related to both risk factor and health outcome to substantial degrees. Conclusions The potential for preventing bias by including some extreme scorers in the sample is high (50–100% in many scenarios). Estimates may then be relatively unbiased in many situations, also at low response rates. Hence, researchers should prioritize to spend their resources on recruiting and retaining at least some individuals with extreme levels of health problems, rather than to obtain very high response rates from people who typically respond to survey studies. This may contribute to preventing bias due to selective non-response in longitudinal studies of risk factors and health outcomes. |
| first_indexed | 2024-12-23T05:46:15Z |
| format | Article |
| id | doaj.art-8be56d2a926745998856613a16a47bb2 |
| institution | Directory Open Access Journal |
| issn | 1471-2288 |
| language | English |
| last_indexed | 2024-12-23T05:46:15Z |
| publishDate | 2019-06-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Medical Research Methodology |
| spelling | doaj.art-8be56d2a926745998856613a16a47bb22022-12-21T17:58:06ZengBMCBMC Medical Research Methodology1471-22882019-06-0119111810.1186/s12874-019-0757-1Preventing bias from selective non-response in population-based survey studies: findings from a Monte Carlo simulation studyKristin Gustavson0Espen Røysamb1Ingrid Borren2Department of Mental Disorders, Norwegian Institute of Public HealthPROMENTA Research Center, Department of Psychology, University of OsloDepartment of Child Development, Norwegian Institute of Public HealthAbstract Background Health researchers often use survey studies to examine associations between risk factors at one time point and health outcomes later in life. Previous studies have shown that missing not at random (MNAR) may produce biased estimates in such studies. Medical researchers typically do not employ statistical methods for treating MNAR. Hence, there is a need to increase knowledge about how to prevent occurrence of such bias in the first place. Methods Monte Carlo simulations were used to examine the degree to which selective non-response leads to biased estimates of associations between risk factors and health outcomes when persons with the highest levels of health problems are under-represented or totally missing from the sample. This was examined under different response rates and different degrees of dependency between non-response and study variables. Results Response rate per se had little effect on bias. When extreme values on the health outcome were completely missing, rather than under-represented, results were heavily biased even at a 70% response rate. In most situations, 50–100% of this bias could be prevented by including some persons with extreme scores on the health outcome in the sample, even when these persons were under-represented. When some extreme scores were present, estimates of associations were unbiased in several situations, only mildly biased in other situations, and became biased only when non-response was related to both risk factor and health outcome to substantial degrees. Conclusions The potential for preventing bias by including some extreme scorers in the sample is high (50–100% in many scenarios). Estimates may then be relatively unbiased in many situations, also at low response rates. Hence, researchers should prioritize to spend their resources on recruiting and retaining at least some individuals with extreme levels of health problems, rather than to obtain very high response rates from people who typically respond to survey studies. This may contribute to preventing bias due to selective non-response in longitudinal studies of risk factors and health outcomes.http://link.springer.com/article/10.1186/s12874-019-0757-1Selective non-responsePreventing biasMonte Carlo simulations |
| spellingShingle | Kristin Gustavson Espen Røysamb Ingrid Borren Preventing bias from selective non-response in population-based survey studies: findings from a Monte Carlo simulation study BMC Medical Research Methodology Selective non-response Preventing bias Monte Carlo simulations |
| title | Preventing bias from selective non-response in population-based survey studies: findings from a Monte Carlo simulation study |
| title_full | Preventing bias from selective non-response in population-based survey studies: findings from a Monte Carlo simulation study |
| title_fullStr | Preventing bias from selective non-response in population-based survey studies: findings from a Monte Carlo simulation study |
| title_full_unstemmed | Preventing bias from selective non-response in population-based survey studies: findings from a Monte Carlo simulation study |
| title_short | Preventing bias from selective non-response in population-based survey studies: findings from a Monte Carlo simulation study |
| title_sort | preventing bias from selective non response in population based survey studies findings from a monte carlo simulation study |
| topic | Selective non-response Preventing bias Monte Carlo simulations |
| url | http://link.springer.com/article/10.1186/s12874-019-0757-1 |
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