INTRODUCTION: Evidence based practice requires showing upon what we are basing medical opinions and guidelines, or recognizing when evidence is absent that guidance is “expert opinion” and research is required to fill evidence gaps. Aerospace is one of the final medical fields to begin organizing a critical summary, adapted periodically, of evidence underpinning operations, and the Aerospace Medicine Systematic Review Group is a new initiative to !ll this gap. This group facilitates high quality, transparent synthesis of evidence, to inform operational medical guidelines in best practice, while simultaneously guiding future research by identifying research gaps. The group has (A) facilitated a second review with the European Space Agency Medical Office to inform human Lunar and Martian mission medical considerations and (B) developed and published, open access, new review methods to aid others to undertake aerospace medicine systematic reviews.
METHODS: (A) Electronic databases were searched from the start of records to April 2016. Studies were assessed with the Cochrane risk of bias tool. Effect size analysis was used to assess the effect of various gravity loading on human biomechanical and cardiopulmonary systems. (B) A new rating scale to appraise technical principles of studies to simulate partial gravity was implemented. Additional method guides for developing questions, protocol drafting, data extracting, quantifying effects and scoring a bed rest study quality were also developed.
RESULTS: (A) The review identified 43 studies that found partial gravity appears unable to protect against cardiovascular and biomechanical changes. (B) The group designed and developed a website (www.aerospacemed.rehab/systematic-review-group) to provide free access to methods developed by the group and provide links to wider resources.
DISCUSSION: The systematic review informed medical considerations for future human exploration missions and demonstrates how systematic synthesis of the evidence base more strongly and better informs medical operations than expert opinion, basic reviews or disordered individual studies. Limitations in the current conduct and reporting of aerospace medicine research are also highlighted. Continuing development of review methods, published as open access guides on the group website and working with review teams globally, will help bring synergy to, and enable high quality summary, of the aerospace medicine evidence base.