Importance: When randomized trials are unavailable or not feasible, observational studies can be used to answer causal questions about the comparative effects of interventions by attempting to emulate a hypothetical pragmatic randomized trial (target trial). Published guidance to aid reporting of these studies is not available.Objective: To develop consensus-based guidance for reporting observational studies performed to estimate causal effects by explicitly emulating a target trial.Design, Setting, and Participants: The Transparent Reporting of Observational Studies Emulating a Target Trial (TARGET) guideline was developed using the Enhancing the Quality and Transparency of Health Research (EQUATOR) framework. The development included (1) a systematic review of reporting practices in published studies that had explicitly aimed to emulate a target trial; (2) a 2-round online survey (August 2023 to March 2024; 18 expert participants from 6 countries) to assess the importance of candidate items selected from previous research and to identify additional items; (3) a 3-day expert consensus meeting (June 2024; 18 panelists) to refine the scope of the guideline and draft the checklist; and (4) pilot of the draft checklist with stakeholders (n = 108; September 2024 to February 2025). The checklist was further refined based on feedback on successive drafts.Findings: The 21-item TARGET checklist is organized into 6 sections (abstract, introduction, methods, results, discussion, other information). TARGET provides guidance for reporting observational studies of interventions explicitly emulating a parallel group, individually randomized target trial, with adjustment for baseline confounders. Key recommendations are to (1) identify the study as an observational emulation of a target trial; (2) summarize the causal question and reason for emulating a target trial, (3) clearly specify the target trial protocol (ie, the causal estimand, identifying assumptions, data analysis plan) and how it was mapped to the observational data, and (4) report the estimate obtained for each causal estimand, its precision, and findings from additional analyses to assess the sensitivity of the estimates to assumptions, and design and analysis choices.Conclusions and Relevance: Application of the TARGET guideline recommendations aims to improve reporting transparency and peer review and help researchers, clinicians, and other readers interpret and apply the results.

Objective: To determine how well exercise interventions are reported in trials in health and disease. Design: Overview of systematic reviews. Data sources: PubMed, EMBASE, CINAHL, SPORTDiscus and PsycINFO from inception until June 2021. Eligibility criteria: Reviews of any health condition were included if they primarily assessed quality of exercise intervention reporting using the Consensus on Exercise Reporting Template (CERT) or the Template for Intervention Description and Replication (TIDieR). We assessed review quality using a modified version of A MeaSurement Tool to Assess systematic Reviews. Results: We identified 7804 studies and included 28 systematic reviews. The median (IQR) percentage of CERT and TIDieR items appropriately reported was 24% (19%) and 49% (33%), respectively. TIDieR items 1, Brief name (median=100%, IQR 4) and 2, Why (median=98%, IQR 6), as well as CERT item 4, Supervision and delivery (median=68%, IQR 89), were the best reported. For replication of exercise interventions, TIDieR item 8, When and how much, was moderately well reported (median=62%, IQR 68) although CERT item 8, Description of each exercise to enable replication (median=23%, IQR 44) and item 13, Detailed description of the exercise intervention (median=24%, IQR 66) were poorly reported. Quality of systematic reviews ranged from moderate to critically low quality. Conclusion: Exercise interventions are poorly reported across a range of health conditions. If exercise is medicine, then how it is prescribed and delivered is unclear, potentially limiting its translation from research to practice. PROSPERO registration number: CRD42021261285; Open Science Framework: osf.io/my3ec/.