ArticlePaediatric and perinatal epidemiology2015
Analysis of Randomised Trials Including Multiple Births When Birth Size Is Informative.
Article in Paediatric and perinatal epidemiology, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 17 papers, 2 of them syntheses that pooled it.
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Who cites it
17 citing papers in PubMed, 2 syntheses or guidelines pooled it, 29 citations in OpenAlex.
- We should do better in accounting for multiple births in neonatal randomised trials: a methodological systematic review.Archives of disease in childhood. Fetal and neonatal edition · 2025Pooled it
- High-dose docosahexaenoic acid for bronchopulmonary dysplasia severity in very preterm infants: a collaborative individual participant data meta-analysis.The American journal of clinical nutrition · 2025Pooled it
- Informative cluster size in cluster-randomised trials: A case study from the TRIGGER trial.Clinical trials (London, England) · 2023Trial
- Mediation Analysis to Untangle Opposing Associations of High-Dose Docosahexaenoic Acid With IQ and Bronchopulmonary Dysplasia in Children Born Preterm.JAMA network open · 2023Trial
- Trial
- An online sample size calculator for designing partially clustered trials.Clinical trials (London, England) · 2026Article
- In vitro Fertilisation and Prolonged Continuous Positive Airway Pressure are Associated with Treatment-Requiring Retinopathy of Prematurity in a Tertiary Referral Cohort: An Exploratory Clinical Epidemiology Study.Clinical ophthalmology (Auckland, N.Z.) · 2026Article
- Sample Size Calculations for Partially Clustered Trials.Statistics in medicine · 2025Article
- Accounting for Twins and Other Multiple Births in Perinatal Studies of Live Births Conducted Using Healthcare Administration Data.Epidemiology (Cambridge, Mass.) · 2025Article
- Accounting for Twins and Other Multiple Births in Perinatal Studies Conducted Using Healthcare Administration Data.medRxiv : the preprint server for health sciences · 2024Article
- Commentary: Estimands in cluster trials: thinking carefully about the target of inferenceand the consequences for analysis choice.International journal of epidemiology · 2023Article
- Estimands in cluster-randomized trials: choosing analyses that answer the right question.International journal of epidemiology · 2023Article
- Re-randomisation trials in multi-episode settings: Estimands and independence estimators.Statistical methods in medical research · 2022Article
- Maternal Thyroid Anomalies and Attention-Deficit Hyperactivity Disorder in Progeny.American journal of epidemiology · 2022Article
- Independence estimators for re-randomisation trials in multi-episode settings: a simulation study.BMC medical research methodology · 2021Article
- Massachusetts' Parental Consent Law and Procedural Timing Among Adolescents Undergoing Abortion.Obstetrics and gynecology · 2019Observational
- Methodological issues in the design and analyses of neonatal research studies: Experience of the NICHD Neonatal Research Network.Seminars in perinatology · 2016Article
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4 authors at 3 institutions in 2 countries.
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Abstract
backgroundInformative birth size occurs when the average outcome depends on the number of infants per birth. Although analysis methods have been proposed for handling informative birth size, their performance is not well understood. Our aim was to evaluate the performance of these methods and to provide recommendations for their application in randomised trials including infants from single and multiple births.
methodsThree generalised estimating equation (GEE) approaches were considered for estimating the effect of treatment on a continuous or binary outcome: cluster weighted GEEs, which produce treatment effects with a mother-level interpretation when birth size is informative; standard GEEs with an independence working correlation structure, which produce treatment effects with an infant-level interpretation when birth size is informative; and standard GEEs with an exchangeable working correlation structure, which do not account for informative birth size. The methods were compared through simulation and analysis of an example dataset.
resultsTreatment effect estimates were affected by informative birth size in the simulation study when the effect of treatment in singletons differed from that in multiples (i.e. in the presence of a treatment group by multiple birth interaction). The strength of evidence supporting the effectiveness of treatment varied between methods in the example dataset.
conclusionsInformative birth size is always a possibility in randomised trials including infants from both single and multiple births, and analysis methods should be pre-specified with this in mind. We recommend estimating treatment effects using standard GEEs with an independence working correlation structure to give an infant-level interpretation.
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