# Update to Trial Forge Guidance 2: addition of the Value of Information criterion

## TL;DR

This paper updates a guideline for deciding if new trials are needed by adding a new criterion that considers the value of additional research and implementation costs.

## Contribution

The addition of the Value of Information criterion to Trial Forge Guidance 2, which evaluates the benefit and uncertainty of trial process strategies.

## Key findings

- The Value of Information criterion was applied to recruitment and retention strategies to assess their potential benefits and uncertainties.
- An electronic tool was developed to calculate and present the Value of Information results for trial teams.
- This update helps trial teams prioritize further studies based on both research value and financial constraints.

## Abstract

Trial Forge Guidance 2 helps trial teams decide if another Study Within A Trial (SWAT) is needed to answer an existing research question. Five criteria are listed to assist decision-making. We are adding a sixth criterion, the Value of Information, to additionally consider the potential time and financial constraints of improving trial process evidence. The Value of Information criterion assesses each trial process based on its value of additional research and value of implementation. We consider evaluations of recruitment and retention strategies as exemplars of how such an approach could be applied to randomised evaluations of trial processes via SWATs. We applied the Value of Information Analysis to all recruitment strategies and categorised them according to their expected benefits in terms of improved recruitment, as well as the level of statistical uncertainty compared to other recruitment strategies. The same approach was followed for retention strategies. To support its use, we have developed an electronic tool that calculates and presents the criterion results for each available evaluation of recruitment and retention strategies. This will enable trial teams to apply the Value of Information criterion, along with the five existing criteria of Trial Forge Guidance 2, when deciding if further SWATs should be prioritised for a particular trial process strategy to provide evidence for the strategy’s use, or not during a trial.

The online version contains supplementary material available at 10.1186/s13063-026-09443-7.