ArticleTrials2018
A study of target effect sizes in randomised controlled trials published in the Health Technology Assessment journal.
Article in Trials, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 37 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
37 citing papers in PubMed, 2 syntheses or guidelines pooled it.
- Effects of mindfulness-based interventions on food craving in adults: a systematic review and meta-analysis of controlled clinical trials.BMC psychology · 2025Pooled it
- A systematic survey of randomised trials that stopped early for reasons of futility.BMC medical research methodology · 2020Pooled it
- Short-Term Effects of Manual Therapy Combined with Functional Magnetic Stimulation in Individuals with Lumbar Disk Herniation with Radiculopathy: A Randomized Clinical Trial.Medicina (Kaunas, Lithuania) · 2026Trial
- Extracorporeal Shockwave Therapy for Diabetes Related Foot Ulcers: A Pilot Three-Arm Double-Blinded Randomised Controlled Trial.International wound journal · 2025Trial
- Effectiveness of a group intervention to improve mental health in siblings of children with chronic disorders: a cluster randomized controlled trial.Journal of pediatric psychology · 2025Trial
- Communication Bridge-2 randomized controlled trial: Recruitment and baseline features.Alzheimer's & dementia : the journal of the Alzheimer's Association · 2025Trial
- Chan-Chuang and resistance exercise for drug rehabilitation: a randomized controlled trial among Chinese male methamphetamine users.Frontiers in public health · 2023Trial
- Exercise versus usual care after non-reconstructive breast cancer surgery (UK PROSPER): multicentre randomised controlled trial and economic evaluation.BMJ (Clinical research ed.) · 2021Trial
- Mind over Matter: Testing the Efficacy of an Online Randomized Controlled Trial to Reduce Distraction from Smartphone Use.International journal of environmental research and public health · 2020Trial
- Feasibility and Acceptability of Mindfulness-based Stress Reduction and Prenatal Sleep Classes for Poor Prenatal Sleep Quality: Pilot Randomized Controlled Trial.Behavioral sleep medicineTrial
- A feasibility randomised controlled trial of Empowered Conversations: training family carers to enhance their relationships and communication with people living with dementia.Pilot and feasibility studies · 2026Article
- How is missing data handled in cluster randomized controlled trials? A review of trials published in the NIHR Journals Library 1997-2024.Clinical trials (London, England) · 2026Review
- The role of research ethics committees in addressing optimism in sample size calculations: a meta-epidemiological study.Research integrity and peer review · 2025Article
- Trial Sequential Analysis for dichotomous outcomes - a practical guide for systematic review protocols.BMC medical research methodology · 2025Article
- The Relationship between Mindful Eating and the Choice of Surgical or Non-Surgical Treatment in Patients with Obesity.Obesity surgery · 2025Article
- Statistical Power in Musculoskeletal Research: A Meta-Review of 266 Randomised Controlled Trials.Sports medicine - open · 2025Review
- Bilateral Prefrontal Cortex Activation During Sensorimotor Tasks in People with Subacute Stroke - An Exploratory Functional Near-Infrared Spectroscopy Study.NeuroRehabilitation · 2025Article
- Primary endpoint acceptance and its association with benefit ratings and market access in German health technology assessments: a retrospective cohort study.The Lancet regional health. Europe · 2025Article
- Comparison of statistical methods for the analysis of patient-reported outcomes (PROs), particularly the Short-Form 36 (SF-36), in randomised controlled trials (RCTs) using standardised effect size (SES): an empirical analysis.Health and quality of life outcomes · 2025Article
- A Mobile Health Intervention in Caregivers of Patients Undergoing Hematopoietic Cell Transplantation: A Randomized Controlled Trial to Examine Health-Related Quality of Life.BMC digital health · 2025Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors.
Funding
Abstract
backgroundWhen designing a randomised controlled trial (RCT), an important consideration is the sample size required. This is calculated from several components; one of which is the target difference. This study aims to review the currently reported methods of elicitation of the target difference as well as to quantify the target differences used in Health Technology Assessment (HTA)-funded trials.
methodsTrials were identified from the National Institute of Health Research Health Technology Assessment journal. A total of 177 RCTs published between 2006 and 2016 were assessed for eligibility. Eligibility was established by the design of the trial and the quality of data available. The trial designs were parallel-group, superiority RCTs with a continuous primary endpoint. Data were extracted and the standardised anticipated and observed effect size estimates were calculated. Exclusion criteria was based on trials not providing enough detail in the sample size calculation and results, and trials not being of parallel-group, superiority design.
resultsA total of 107 RCTs were included in the study from 102 reports. The most commonly reported method for effect size derivation was a review of evidence and use of previous research (52.3%). This was common across all clinical areas. The median standardised target effect size was 0.30 (interquartile range: 0.20-0.38), with the median standardised observed effect size 0.11 (IQR 0.05-0.29). The maximum anticipated and observed effect sizes were 0.76 and 1.18, respectively. Only two trials had anticipated target values above 0.60.
conclusionThe most commonly reported method of elicitation of the target effect size is previous published research. The average target effect size was 0.3. A clear distinction between the target difference and the minimum clinically important difference is recommended when designing a trial. Transparent explanation of target difference elicitation is advised, with multiple methods including a review of evidence and opinion-seeking advised as the more optimal methods for effect size quantification.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.