SPIRIT statement

The protocol is like an architect plan for a new house. It must be explicit, detailed and accurate for the justification of the trial, the methods, and the implementation of every step of the clinical study. The protocol is important and crucial for many reasons. The protocol provides the information needed for the study to be implemented consistently across collaborators in a way that mirrors the intentions of the principal investigators. For external groups who review the trial, such as institutional review board, journal editors and referees, the protocol provides a window into the nature of the study. The protocol allows systematic reviewers to assess an important domain in the risk of bias, the reporting bias by providing a transparent way to verify the consistency between the final report and the original intent.

In spite of the paramount importance of the study protocol, there is accumulating evidence that many protocols do not fully address important study elements. Incomplete protocol content can impair understanding and implementation of the trial.

In response to observed deficiencies in protocol content, the SPIRIT Initiative has produced recommendations for minimum relevant protocol items to include in a protocol.  The SPIRIT statement was recently published along with Explanation and Elaboration.

The strengths that distinguish SPIRIT from other protocol guidance documents include its systematic and transparent development methods; participation of a wide range of key stakeholders; use of empirical evidence to support its recommendations; and availability of detailed guidance including model examples from protocols. It adheres to the ethical principles mandated by the 2008 Declaration of Helsinki, and encompasses the protocol items recommended by the International Conference on Harmonisation Good Clinical Practice E6 guidance. SPIRIT 2013 also supports trial registration requirements from the World Health Organization and the International Committee of Medical Journal Editors.

The SPIRIT statement is available for download SPIRIT 2013 explanation and elaboration guidance for protocols of clinical trials and SPIRIT 2013 Statement Defining Standard Protocol Items for Clinical Trials


Chan A-W, Tetzlaff JM, Altman DG, Laupacis A, Gøtzsche PC, Krleža-Jerić K, Hróbjartsson A, Mann H, Dickersin K, Berlin J, Doré C, Parulekar W, Summerskill W, Groves T, Schulz K, Sox H, Rockhold FW, Rennie D, Moher D. SPIRIT 2013 Statement: Defining standard protocol items for clinical trials. Ann Intern Med. 2013;158(3):200-207.

Chan A-W, Tetzlaff JM, Gøtzsche PC, Altman DG, Mann H, Berlin J, Dickersin K, Hróbjartsson A, Schulz KF, Parulekar WR, Krleža-Jerić K, Laupacis A, Moher D. SPIRIT 2013 Explanation and Elaboration: Guidance for protocols of clinical trials. BMJ 2013;346:e7586.

Chan A-W, Tetzlaff J, Altman D, Dickersin K, Moher D. SPIRIT: New guidance for content of clinical trial protocols. Lancet 2013;381:91-2.

Tetzlaff JM, Chan A-W, Kitchen J, Sampson M, Tricco A, Moher D. Guidelines for randomized clinical trial protocol content: a systematic review. Syst Rev 2012;1:43.

Tetzlaff JM, Moher D, Chan A-W. Developing a guideline for clinical trial protocol content: Delphi consensus survey. Trials 2012;13:176.