Statistical analysis plan for Fluid Optimisation in Emergency Laparotomy (FLO-ELA) Trial; a multi-centre randomised trial of cardiac output-guided fluid therapy compared to usual care in patients undergoing major emergency gastrointestinal surgery
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Background
FLO-ELA is a multi-centre, parallel-group, open-label, randomised controlled trial (RCT) looking at the effect of minimally invasive cardiac output monitoring in the management of patients aged 50 years and above undergoing emergency gastrointestinal surgery. The primary outcome is days alive and out of hospital within 90 days of randomisation (DAOH-90). This article describes the statistical analysis plan (SAP) for this trial. The estimand and analytical approach presented here may be appropriate for clinical trials in a similar setting (critical care surgery).
Methods and design
FLO-ELA is a superiority trial, incorporating an early-stage pilot phase, conducted at 63 UK hospitals. Participants are randomised on a 1:1 basis to the intervention or control group using a minimisation algorithm which balances on the following two factors (i) age, split into 3 groups, and (ii) American Society of Anesthesiologists (ASA) category, 5 categories on an ordinal scale reflecting participants’ baseline co-morbidities. In this SAP, we define the estimands and strategies for handling intercurrent events for each study outcome, then give a detailed description of planned analyses including general analytical principles, analytical framework for primary, secondary and process measure outcomes, approach to missing data and supplementary analyses looking at heterogeneity in treatment effect between key subgroups and potential differences in outcomes pre and post onset of Covid pandemic in the UK.
Trial registration
ISRCTN 14729158. Registered on 02 May 2017.
FLO-ELA is a multi-centre, parallel-group, open-label, randomised controlled trial (RCT) looking at the effect of minimally invasive cardiac output monitoring in the management of patients aged 50 years and above undergoing emergency gastrointestinal surgery. The primary outcome is days alive and out of hospital within 90 days of randomisation (DAOH-90). This article describes the statistical analysis plan (SAP) for this trial. The estimand and analytical approach presented here may be appropriate for clinical trials in a similar setting (critical care surgery).
Methods and design
FLO-ELA is a superiority trial, incorporating an early-stage pilot phase, conducted at 63 UK hospitals. Participants are randomised on a 1:1 basis to the intervention or control group using a minimisation algorithm which balances on the following two factors (i) age, split into 3 groups, and (ii) American Society of Anesthesiologists (ASA) category, 5 categories on an ordinal scale reflecting participants’ baseline co-morbidities. In this SAP, we define the estimands and strategies for handling intercurrent events for each study outcome, then give a detailed description of planned analyses including general analytical principles, analytical framework for primary, secondary and process measure outcomes, approach to missing data and supplementary analyses looking at heterogeneity in treatment effect between key subgroups and potential differences in outcomes pre and post onset of Covid pandemic in the UK.
Trial registration
ISRCTN 14729158. Registered on 02 May 2017.
Date Issued
2026-12-01
Date Acceptance
2026-02-06
Citation
Trials, 2026, 27 (1)
ISSN
1745-6215
Publisher
BMC
Journal / Book Title
Trials
Volume
27
Issue
1
Copyright Statement
© The Author(s) 2026. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/41998794
PII: 10.1186/s13063-026-09552-3
Subjects
Days alive and out of hospital
Emergency laparotomy
Estimand
Length of stay
Mortality
Perioperative care
Statistical analysis plan
Publication Status
Published
Coverage Spatial
England
Article Number
397
Date Publish Online
2026-04-17