Background: The randomised controlled trial is widely considered to be the gold standard study for comparing the effectiveness of health interventions. Central to its design is a calculation of the number of participants needed (the sample size) for the trial. The sample size is typically calculated by specifying the magnitude of the difference in the primary outcome between the intervention effects for the population of interest. This difference is called the 'target difference' and should be appropriate for the principal estimand of interest and determined by the primary aim of the study. The target difference between treatments should be considered realistic and/or important by one or more key stakeholder groups.
Objective: The objective of the report is to provide practical help on the choice of target difference used in the sample size calculation for a randomised controlled trial for researchers and funder representatives.
Methods: The Difference ELicitation in TriAls (DELTA) recommendations and advice were developed through a five-stage process, which included two literature reviews of existing funder guidance and recent methodological literature; a Delphi process to engage with a wider group of stakeholders; a 2-day workshop; and finalising the core document.
Results: Advice is provided for definitive trials (Phase III/IV studies). Methods for choosing the target difference are reviewed. To aid those new to the topic, and to encourage better practice, 10 recommendations are made regarding choosing the target difference and undertaking a sample size calculation. Recommended reporting items for trial proposal, protocols and results papers under the conventional approach are also provided. Case studies reflecting different trial designs and covering different conditions are provided. Alternative trial designs and methods for choosing the sample size are also briefly considered.
Conclusions: Choosing an appropriate sample size is crucial if a study is to inform clinical practice. The number of patients recruited into the trial needs to be sufficient to answer the objectives; however, the number should not be higher than necessary to avoid unnecessary burden on patients and wasting precious resources. The choice of the target difference is a key part of this process under the conventional approach to sample size calculations. This document provides advice and recommendations to improve practice and reporting regarding this aspect of trial design. Future work could extend the work to address other less common approaches to the sample size calculations, particularly in terms of appropriate reporting items.
Funding: Funded by the Medical Research Council (MRC) UK and the National Institute for Health Research as part of the MRC-National Institute for Health Research Methodology Research programme.
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http://dx.doi.org/10.3310/hta23600 | DOI Listing |
Cureus
December 2024
College of Medicine, Alfaisal University, Riyadh, SAU.
Smell and taste sensations have been linked to positive outcomes in the feeding of premature infants, though the impact on the time required to transition to oral feeding remains unclear. This study aimed to evaluate the beneficial effects of smell and taste interventions on clinical outcomes in preterm infants. We conducted a search in PubMed, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials from inception through September 2024 for randomized controlled trials (RCTs) examining the effects of smell and taste on clinical outcomes in preterm infants with a gestational age of less than 34 weeks.
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December 2024
College of Nursing, QU-Health Sector, Qatar University, Doha, Qatar.
Introduction: The evolving landscape of healthcare in Jordan presents unique challenges and opportunities for nursing professionals. With a focus on critical care nurses, understanding the dynamics of professional autonomy and professionalism within this context is crucial for advancing nursing practice and improving patient care.
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J Mood Anxiety Disord
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Department of Psychiatry, New York University Grossman School of Medicine, 1 Park Ave, New York, NY, United States.
Anxiety disorders are highly comorbid with sleep disturbance and have also been associated with deficits in emotion regulation, the ability to control and express emotions. However, the extent to which specific dimensions of sleep disturbance and emotion regulation are associated with anxiety diagnosis is not well-explored. This study examined dimensions of emotion regulation and sleep disturbance that may predict greater likelihood of anxiety diagnosis using novel machine learning techniques.
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Background: Surgical site infections (SSI) following clean abdominal surgery in cattle pose significant economic and welfare concerns. Preoperative skin asepsis aims to minimize microbial load over the surgical field before and throughout surgery to minimize its risk. While chlorhexidine (CHX) and povidone-iodine (PVI) are commonly used antiseptics for this purpose, our study introduces the so far unexplored use of octenidine (OCT) in veterinary surgery.
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Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China.
Meat rabbits are a small herbivorous livestock and have been popularly raised in China for producing high-quality meat. Therefore, it is economically important to genetically improve both carcass performance and meat quality in meat rabbits. However, we still know less about the underlying candidate genes that may determine phenotypic variation on carcass and meat traits of meat rabbits.
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