Yelland, LN;
Sullivan, TR;
Pavlou, M;
Seaman, SR;
(2015)
Analysis of Randomised Trials Including Multiple Births When Birth Size Is Informative.
Paediatric and Perinatal Epidemiology
, 29
(6)
pp. 567-575.
10.1111/ppe.12228.
Preview |
Text
Pavlou_Informative Cluster Size for Perinatal Trials Main Article Accepted.pdf Download (286kB) | Preview |
Abstract
BACKGROUND: Informative 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. METHODS: Three 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. RESULTS: Treatment 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. CONCLUSIONS: Informative 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.
| Type: | Article |
|---|---|
| Title: | Analysis of Randomised Trials Including Multiple Births When Birth Size Is Informative |
| Location: | England |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1111/ppe.12228 |
| Publisher version: | http://dx.doi.org/10.1111/ppe.12228 |
| Language: | English |
| Additional information: | This is the peer reviewed version of the following article: Yelland, LN; Sullivan, TR; Pavlou, M; Seaman, SR; (2015) Analysis of Randomised Trials Including Multiple Births When Birth Size Is Informative. Paediatric and Perinatal Epidemiology, 29 (6) pp. 567-575, which has been published in final form at: http://dx.doi.org/10.1111/ppe.12228. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving (http://olabout.wiley.com/WileyCDA/Section/id-828039.html#terms). |
| Keywords: | clustering, generalised estimating equations, informative cluster size, multiple births, statistical methodology |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Statistical Science |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1490782 |
Archive Staff Only
 |
View Item |
