Well-conducted mediation analyses have the potential to move implementation science forward by better understanding how or why implementation strategies cause their effects on outcomes. The AGReMA statement provides authors with recommendations for reporting primary and secondary mediation analyses of randomized trials and observational studies. Improved reporting of studies that use mediation analyses could help produce publications that are complete, accurate, transparent, and reproducible.

暂无摘要。

Mediation analyses of randomized trials and observational studies can generate evidence about the mechanisms by which interventions and exposures may influence health outcomes. Publications of mediation analyses are increasing, but the quality of their reporting is suboptimal.
To develop international, consensus-based guidance for the reporting of mediation analyses of randomized trials and observational studies (A Guideline for Reporting Mediation Analyses; AGReMA).
The AGReMA statement was developed using the Enhancing Quality and Transparency of Health Research (EQUATOR) methodological framework for developing reporting guidelines. The guideline development process included (1) an overview of systematic reviews to assess the need for a reporting guideline; (2) review of systematic reviews of relevant evidence on reporting mediation analyses; (3) conducting a Delphi survey with panel members that included methodologists, statisticians, clinical trialists, epidemiologists, psychologists, applied clinical researchers, clinicians, implementation scientists, evidence synthesis experts, representatives from the EQUATOR Network, and journal editors (n = 19; June-November 2019); (4) having a consensus meeting (n = 15; April 28-29, 2020); and (5) conducting a 4-week external review and pilot test that included methodologists and potential users of AGReMA (n = 21; November 2020).
A previously reported overview of 54 systematic reviews of mediation studies demonstrated the need for a reporting guideline. Thirty-three potential reporting items were identified from 3 systematic reviews of mediation studies. Over 3 rounds, the Delphi panelists ranked the importance of these items, provided 60 qualitative comments for item refinement and prioritization, and suggested new items for consideration. All items were reviewed during a 2-day consensus meeting and participants agreed on a 25-item AGReMA statement for studies in which mediation analyses are the primary focus and a 9-item short-form AGReMA statement for studies in which mediation analyses are a secondary focus. These checklists were externally reviewed and pilot tested by 21 expert methodologists and potential users, which led to minor adjustments and consolidation of the checklists.
The AGReMA statement provides recommendations for reporting primary and secondary mediation analyses of randomized trials and observational studies. Improved reporting of studies that use mediation analyses could facilitate peer review and help produce publications that are complete, accurate, transparent, and reproducible.

Many people overestimate the amount of alcohol that increases their risk of harm and so may not perceive any need to change their drinking behaviour. Several countries have developed low-risk drinking guidelines, yet awareness of these guidelines remains low. Furthermore, mass media campaigns about alcohol-related harms may have limited impact if people do not perceive their current consumption as potentially harmful. Integrating drinking guidelines into media campaigns about alcohol\'s harms can concurrently provide drinkers with information about low-risk drinking levels and compelling reasons to comply.
Our aim was to build understanding of the effectiveness of messages about the long-term harms of drinking and low-risk drinking guidelines, by testing the mediating effects of estimates of harmful drinking levels and attitudes towards drinking alcohol on subsequent intentions and behaviours.
In an online experiment conducted in 2016, n = 1156 Australian adult monthly drinkers were randomly assigned to view advertisements for non-alcohol products (NON-ALC; control), advertisements featuring long-term harms of alcohol (LTH), or LTH advertisements plus a guideline message (LTH + G). Immediately following exposure, we measured estimates of harmful drinking levels and attitudes towards drinking alcohol. One week later, we measured intentions to drink less and behavioural compliance with the guideline.
Compared to NON-ALC advertisements, exposure to LTH + G advertisements increased (i) the proportion of respondents who correctly estimated harmful drinking levels, which in turn, strengthened intentions to drink less (42% of the total effect was mediated), and (ii) negative attitudes, which in turn, also increased intentions to drink less (35% mediated) and behavioural compliance (24% mediated). Compared to NON-ALC, LTH advertisements increased negative attitudes, which in turn strengthened intentions to drink less (53% mediated).
When paired with effective alcohol harm reduction television advertisements, messages promoting low-risk drinking guidelines can increase drinkers\' intentions to reduce their alcohol consumption and compliance with low-risk drinking guidelines.

There are a growing number of studies using mediation analysis to understand the mechanisms of health interventions and exposures. Recent work has shown that the reporting of these studies is heterogenous and incomplete. This problem stifles clinical application, reproducibility, and evidence synthesis. This paper describes the processes and methods that will be used to develop a guideline for reporting studies of mediation analyses (AGReMA).
AGReMA will be developed over five overlapping stages. Stage one will comprise a systematic review to examine relevant evidence on the quality of reporting in published studies that use mediation analysis. In the second stage we will consult a group of methodologists and applied researchers by using a Delphi process to identify items that should be considered for inclusion in AGReMA. The third stage will involve a consensus meeting to consolidate and prioritise key items to be included in AGReMA. The fourth stage will involve the production of AGReMA and an accompanying explanation and elaboration document. In the final stage we will disseminate the AGReMA statement via journals, conferences, and professional meetings across multiple disciplines.
The development and implementation of AGReMA will improve the standardization, transparency, and completeness in the reporting of studies that use mediation analysis to understand the mechanisms of health interventions and exposures.