Abstract
BackgroundIn observational research, choosing an optimal analysis strategy when variables are incomplete requires an understanding of the factors associated with ongoing participation and non-response, but this cannot be fully examined with incomplete data. Linkage to external datasets provides additional information on those with incomplete data, allowing examination of factors related to missingness.MethodsWe examined the association between baseline sociodemographic factors and ongoing participation in the Avon Longitudinal Study of Parents and Children. We investigated whether child and adolescent outcomes measured in linked education and primary care data were associated with participation, after accounting for baseline factors. To demonstrate the potential for bias, we examined whether the association between maternal smoking and these outcomes differed in the subsample who completed the 19-year questionnaire.ResultsLower levels of school attainment, lower general practitioner (GP) consultation and prescription rates, higher body mass index (BMI), special educational needs (SEN) status, not having an asthma diagnosis, depression and being a smoker were associated with lower participation after adjustment for baseline factors. For example, the adjusted odds ratio (OR) for participation comparing ever smokers (by 18 years) with non-smokers was: 0.65, 95% CI (0.56, 0.75). The associations with maternal smoking differed between the subsample of participants at 19 years and the entire sample, although differences were small and confidence intervals overlapped. For example: for SEN status, OR = 1.19 (1.06, 1.33) (all participants); OR = 1.03 (0.79, 1.45) (subsample).ConclusionsA range of health-related and educational factors are associated with ongoing participation in ALSPAC; this is likely to be the case in other cohort studies. Researchers need to be aware of this when planning their analysis. Cohort studies can use linkage to routine data to explore predictors of ongoing participation and conduct sensitivity analyses to assess potential bias.
Highlights
IntroductionNon-response and dropout from longitudinal studies (we will refer to not dropping out/response as participation) result in missing study information
Non-response and dropout from longitudinal studies result in missing study information
We found that participation in Avon Longitudinal Study of Parents and Children (ALSPAC) is associated with a wide range of baseline sociodemographic factors; in all cases, factors suggesting greater social disadvantage were associated with lower participation
Summary
Non-response and dropout from longitudinal studies (we will refer to not dropping out/response as participation) result in missing study information. One way to address this is by using genetic information.[3,4] A recent study using Avon Longitudinal Study of Parents and Children (ALSPAC) data[3] found that, in both the mothers and the index children, polygenic scores for years of education and agreeableness were associated with greater participation; polygenic scores for smoking initiation, schizophrenia, attention-deficit hyperactivity disorder (ADHD) and depression were associated with lower levels of participation. Conclusions: A range of health-related and educational factors are associated with ongoing participation in ALSPAC; this is likely to be the case in other cohort studies
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
