eprintid: 10083383
rev_number: 19
eprint_status: archive
userid: 608
dir: disk0/10/08/33/83
datestamp: 2019-10-15 10:13:30
lastmod: 2021-12-29 23:25:40
status_changed: 2019-10-15 10:13:30
type: article
metadata_visibility: show
creators_name: Godolphin, PJ
creators_name: Godolphin, EJ
title: Robustness of crossover trials against subject drop-out - Examples of perpetually connected designs
ispublished: pub
divisions: UCL
divisions: B02
divisions: D65
divisions: J38
keywords: Crossover design, subject drop-out, missing data, clinical trial, uniformly balanced repeated measurement design, perpetually connected
note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
abstract: When performing a repeated measures experiment, such as a clinical trial, there is a risk of subject drop-out during the experiment. If one or more subjects leave the study prematurely, a situation could arise where the eventual design is disconnected, implying that very few treatment contrasts for both direct effects and carryover effects are estimable. This paper aims to identify experimental conditions where this problem with the eventual design can be avoided. It is shown that in the class of uniformly balanced repeated measurement designs consisting of two or more Latin squares, there are planned designs with the following useful property. Provided that all subjects have completed the first two periods of study, such a design will not be replaced by a disconnected eventual design due to drop-out, irrespective of the type of drop-out behaviour that may occur. Designs with this property are referred to as perpetually connected. These experimental conditions are identified and examined in the paper and an example of at least one perpetually connected uniformly balanced repeated measurement design is given in each case. The results improve upon previous contributions in the literature that have been confined largely to cases in which drop-out occurs only in the final periods of study.
date: 2019-03-01
date_type: published
publisher: SAGE PUBLICATIONS LTD
official_url: https://doi.org/10.1177/0962280217736541
oa_status: green
full_text_type: other
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 1697190
doi: 10.1177/0962280217736541
lyricists_name: Godolphin, Peter
lyricists_id: PGODO03
actors_name: Godolphin, Peter
actors_id: PGODO03
actors_role: owner
full_text_status: public
publication: Statistical Methods in Medical Research
volume: 28
number: 3
pagerange: 788-800
pages: 13
issn: 1477-0334
citation:        Godolphin, PJ;    Godolphin, EJ;      (2019)    Robustness of crossover trials against subject drop-out - Examples of perpetually connected designs.                   Statistical Methods in Medical Research , 28  (3)   pp. 788-800.    10.1177/0962280217736541 <https://doi.org/10.1177/0962280217736541>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10083383/1/robustness-crossover-trials_FINAL.pdf