Causal Inference
Transparent Reporting of Observational Studies Emulating a Target Trial: The TARGET Statement Harrison* Harrison Hansford Aidan Cashin Sonja Swanson Matthew Jones Nazrul Islam Issa Dahabreh Barbra Dickerman Matthias Egger Xabier Garcia-Albeniz Robert Golub Sara Lodi Margarita Moreno-Betancur Sallie-Anne Pearson Sebastian Schneeweiss Jonathan Sterne Melissa Sharp Elizabeth Stuart Hopin Lee Miguel Hernán James McAuley
Aim
To develop international, consensus-based guidance for reporting studies that use the target trial framework to estimate the effect of interventions using observational data.
Methods
The TARGET (Transparent Reporting of Observational Studies Emulating a Target Trial) guideline was developed following methodological guidance from the EQUATOR Network. This included a systematic review of reporting practices in studies that explicitly aimed to emulate a target trial; a 2-round online survey (Aug 2023-Mar 2024; 18 expert participants) to identify and refine items selected from previous research; an expert consensus meeting (Jun 2024; 18 panellists) to refine the scope of the guideline and draft the checklist; and an external piloting activity with stakeholders (n=66; Sept 2024-Dec 2024). The checklist was revised based on piloting feedback.
Results
The TARGET guideline is focussed on observational studies of interventions that explicity emulate a target trial. The 27-item TARGET checklist is organized into 7 sections (abstract, introduction, methods, results, discussion, open science, and patient & public involvement). Key recommendations are (1) the causal question should be stated, including the reason for emulating a target trial, (2) the target trial protocol should be clearly defined (ie. causal estimand, identifying assumptions, data analysis plan) and how these components were mapped to the observational data should be thoroughly described, and (3) for each causal estimand, the estimate obtained and its precision should be reported along with findings from additional analyses to assess robustness to potential violations of assumptions and design and analysis choices.
Discussion
The TARGET guideline provides recommendations on reporting of studies explicitly emulating a target trial. Use of the guideline should facilitate transparency in their reporting to improve peer review, and help researchers, clinicians and other readers interpret and use the results