Protocol for development of SPIRIT and CONSORT extensions for reporting climate and environmental outcomes in randomised trials (SPIRIT-ICE and CONSORT-ICE)

INTRODUCTION: The WHO has declared climate change the defining public health challenge of the 21st century. Incorporating climate and environmental outcomes in randomised trials is essential for enhancing healthcare treatments' sustainability and safeguarding global health. To implement such outcomes, it is necessary to establish a framework for unbiased and transparent planning and reporting. We aim to develop extensions to the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT 2025) and Consolidated Standards of Reporting Trials (CONSORT 2025) statements by introducing guidelines for reporting climate and environmental outcomes. METHODS AND ANALYSIS: This is a protocol for SPIRIT and CONSORT extensions on reporting climate and environmental outcomes in randomised trials termed SPIRIT-Implementing Climate and Environmental (ICE) and CONSORT-ICE. The development of the extensions will consist of five phases: phase 1-project launch, phase 2-review of the literature, phase 3-Delphi survey, phase 4-consensus meeting and phase 5-dissemination and implementation. The phases are expected to overlap. The SPIRIT-ICE and CONSORT-ICE extensions will be developed in parallel. The extensions will guide researchers on how and what to report when assessing climate and environmental outcomes. ETHICS AND DISSEMINATION: The protocol was submitted to the Danish Research Ethics Committees, Denmark in June 2025. Ethics approval is expected in September 2025. The SPIRIT and CONSORT extensions will be published in international peer-reviewed journals.