In cluster-randomised trials (CRTs), different estimands can be targeted, such as the individual- or cluster-average effect. These two estimands can differ in magnitude when outcomes or treatment effe...

Sequential Multiple Assignment Randomised Trials (SMARTs) offers a robust methodology for developing adaptive, personalised interventions, but their unfamiliarity may limit accessibility for patients ...

The Oxford Hip Score (OHS) is widely used as a patient reported outcome measure in clinical studies and national quality databases. The content of the questionnaire suggests a potential two-subscale s...

External validation is essential for assessing the generalisability and transportability of a clinical prediction model. A previous review of studies published in 2010 identified substantial deficienc...

To describe and characterize three partly coexisting evidentiary configurations in drug regulation and health technology assessment (HTA), and to examine the inferential consequences of the progressiv...

Adequate sample size is essential to the development of new prediction models with binary outcomes. We aim to relate recent approaches to traditional rules of thumb (‘simple rules’) and assess agreeme...

Diagnostic accuracy studies that compare two or more index tests (comparative diagnostic accuracy studies) can be at risk of generating biased results due to shortcomings in the statistical analysis. ...

The reliability of confirmatory clinical trials (i.e. the post-trial probability) depends on the pre-trial probability. During the COVID-19 pandemic, many early COVID-19 confirmatory trials were launc...

When pursuing participatory methods with youth, healthcare research teams may have the opportunity to create partnerships with transgender and gender diverse youth (TGDY). While these partnerships are...

Treatment withdrawal effects represent a transient increase in clinical risk following treatment discontinuation that exceeds what would be expected from loss of treatment effect alone. They have been...

Observational studies evaluating treatment strategies that are indistinguishable at the start of follow-up are prone to immortal-time bias, in its misclassification form. The clone-censor-weight (CCW)...

Systematic reviews (SRs) support patient-centered decision-making and should therefore synthesize evidence about outcomes that are most important to patients. Rehabilitation is a core component of hea...

To enhance effect size (ES) interpretation in epilepsy patient-reported outcome measures, focusing on single-item global rating (SIGR) and multi-item scales (MIS), by deriving evidence-based threshold...

To update and expand an existing framework for diagnostic accuracy study designs in low-prevalence settings, evaluate its applicability to newborn screening (NBS) for rare and ultra-rare conditions, a...

Target trial emulation offers a structured framework to reduce bias in observational studies by emulating the design of a hypothetical target randomised controlled trial. Despite a growing interest fo...

To identify and prioritise opportunities to strengthen methodological and process innovation in global evidence synthesis, ensuring timely, equitable, and high-quality syntheses that can inform decisi...

Recent studies have raised concerns arising from the exploitation (“mining”) of public health databases for low-quality, mass-produced papers. However, it remains challenging to disambiguate whether s...

Higher adiposity in early-life has consistently been associated with a reduced risk of breast cancer in later life, with Mendelian randomization (MR) studies supporting a causal effect. However, conce...

In our November 2025 Editors' Choice, we issued a call for further submissions [1] on the topic of living guidelines [2]. Living guidelines represent an advancement in guideline development, enabling ...

Recruitment and retention difficulties remain major threats to the success, efficiency, and value of clinical trials, yet robust evidence on how to address these challenges is limited. Studies Within ...

Within a meta-analytic framework, validating surrogate endpoints traditionally requires individual patient data (IPD) from multiple randomized controlled trials (RCTs). This is rarely feasible in rare...

During the last decade, immune checkpoint inhibitor therapy, including anti-PD-1 monotherapy, has revolutionized the prognosis of advanced cutaneous melanoma. Nonetheless, it remains unclear whether a...

Multiple stakeholders need to locate results of registered clinical trials but frequently struggle to find them. Summary results of clinical trials are often not published in trial registries, and pub...

Health researchers benefit from methods guidance (MG) for planning, conducting, analyzing and interpreting research studies. How to develop MG that is trustworthy and researcher-friendly is unclear; e...

The AGREE II, released in 2010, is an international gold standard for assessing the quality of guidelines. Since then, conceptual and methodological advancements in the field of livingness have emerge...

This review aimed to identify and characterise tools designed, adapted, or validated to assess risk of bias (RoB) in causal real-world evidence (RWE), with a view to informing their potential use in e...

To determine whether methodological trade-offs used in rapid reviews result in changes in treatment effects or GRADE certainty of the evidence (COE) compared to systematic reviews.

To describe a co-designed Participant Information and Consent Form (PICF) developed to improve accessibility for ethnically diverse communities and consider implications for research representativenes...

Scoping reviews are often conducted as a precursor to a systematic review, yet guidance on how this relationship should be planned, executed and reported is limited. We aimed to illustrate, through wo...

As a journal that prioritises meta-research, it is inevitable that the strapline of many published articles may translate as “could do better”. With this in mind, and as instigated by our predecessors...

The growing use of the term “real-world evidence” (RWE) has introduced a classification of clinical research based on its perceived proximity to routine practice rather than its methodological charact...

Randomised controlled trials (RCTs) remain the gold standard for causal inference but are often resource-intensive, time-consuming, and operationally complex to conduct. The growing availability of re...

Guideline development is both time-consuming and resource-intensive, and duplication of efforts contribute to research waste. Although adopting existing guidelines is an efficient alternative, it ofte...

Real-world data are increasingly used to support pragmatic clinical trials. However, most existing oncology cohorts lack high-frequency symptom data and standardized infrastructures required for longi...

To examine the barriers and enablers to integrating evidence-based deprescribing recommendations into clinical practice guidelines.

To identify the reporting characteristics and recommended design features of mapping reviews for public health decision-makers.

Living systematic reviews (LSRs) aim to synthesize all available evidence meeting pre-specified eligibility criteria to answer a research question and to continually update the review by incorporating...

Rule-out diagnostic-management studies ask whether a clinical decision rule combined with a biomarker can safely spare patients an imaging test — for example, the YEARS algorithm and D-dimer versus co...

Comparative evaluations of machine learning (ML) and logistic regression (LR) for clinical prediction frequently report ML as superior, but the methodological framework producing those comparisons has...

To assess the prevalence of spin in medical publications across different study designs and disciplines and to identify related factors for spin, through a systematic review of research-on-research st...

For at least 3 decades Clinical Practice Guidelines (CPGs) have been an important building block to improve the quality and consistency of health and social care provided to patients and communities a...

The Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group is developing GRADErater (GRADE Rating Automation Through Enhanced Reasoning), an official, automated tool f...

To characterize harms specification, harms reporting, concordance between specified and reported harms, transparency about harms reporting criteria, and equity-related harms reporting in randomized co...

Decision-making capacity (DMC) is a prerequisite for valid informed consent, as well as being a key methodological requirement in clinical and epidemiological research. For individuals with neurocogni...

•CHA studies have evaluated general health advice from generative AI (GAI) models.•CHA studies now assess tailored clinical decision support for individual patients.•Consensus is needed on how to vali...