ArticleBMC family practice2009
The external validity of published randomized controlled trials in primary care.
Article in BMC family practice, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 21 papers, 1 of them a synthesis 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
21 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Exclusion rates in randomized controlled trials of treatments for physical conditions: a systematic review.Trials · 2020Pooled it
- Model of integrated mental health video consultations for people with depression or anxiety in primary care (PROVIDE-C): assessor masked, multicentre, randomised controlled trial.BMJ (Clinical research ed.) · 2024Trial
- The implementation and utility of patient screening logs in a multicentre randomised controlled oncology trial.Trials · 2020Trial
- Trial
- Trial
- Sustained effectiveness of a multifaceted intervention to reduce potentially inappropriate prescribing in older patients in primary care (OPTI-SCRIPT study).Implementation science : IS · 2016Trial
- Effectiveness of a Multifaceted Intervention for Potentially Inappropriate Prescribing in Older Patients in Primary Care: A Cluster-Randomized Controlled Trial (OPTI-SCRIPT Study).Annals of family medicine · 2015Trial
- Trial
- Implementation of self management support for long term conditions in routine primary care settings: cluster randomised controlled trial.BMJ (Clinical research ed.) · 2013Trial
- Eligibility of patients with chronic obstructive pulmonary disease for inclusion in randomised control trials investigating triple therapy: a study using routinely collected data.Respiratory research · 2024Article
- Policy brief: Improving national vaccination decision-making through data.Frontiers in public health · 2024Article
- Data Challenges for Externally Controlled Trials: Viewpoint.Journal of medical Internet research · 2023Article
- Clinical drug trials in general practice: how well are external validity issues reported?BMC family practice · 2017Review
- Eligibility of real-life patients with COPD for inclusion in trials of inhaled long-acting bronchodilator therapy.Respiratory research · 2016Article
- Meeting the Challenges of Intervention Research in Health Science: An Argument for a Multimethod Research Approach.The patient · 2016Article
- How to assess the external validity and model validity of therapeutic trials: a conceptual approach to systematic review methodology.Evidence-based complementary and alternative medicine : eCAM · 2014Review
- SPIRIT 2013 explanation and elaboration: guidance for protocols of clinical trials.BMJ (Clinical research ed.) · 2013 · on this mapArticle
- Article
- The importance of primary care research in the management of respiratory disease.Primary care respiratory journal : journal of the General Practice Airways Group · 2012Article
- To whom do the results of the multicenter, randomized, controlled INSECT trial (ISRCTN 24023541) apply?--assessment of external validity.BMC surgery · 2012Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors.
Funding
Abstract
backgroundA criticism of Randomized Controlled Trials (RCTs) in primary care is that they lack external validity, participants being unrepresentative of the wider population. Our aim was to determine whether published primary care-based RCTs report information about how the study sample is assembled, and whether this is associated with RCT characteristics.
methodsWe reviewed RCTs published in four primary care journals in the years 2001-2004. Main outcomes were: (1) eligibility fraction (proportion eligible of those screened), (2) enrolment fraction (proportion randomised of those eligible), (3) recruitment fraction (proportion of potential participants actually randomised), and (4) number of patients needed to be screened (NNS) in order to randomize one participant.
resultsA total of 148 RCTs were reviewed. One hundred and three trials (70%) reported the number of individuals assessed by investigators for eligibility, 119 (80%) reported the number eligible for participation, and all reported the actual number recruited. The median eligibility fraction was 83% (IQR 40% to 100%), and the median enrolment fraction was 74% (IQR 49% to 92%). The median NNS was 2.43, with some trials reportedly recruiting every patient or practice screened for eligibility, and one trial screening 484 for each patient recruited. We found no association between NNS and journal, trial size, multi- or single-centre, funding source or type of intervention. There may be associations between provision of sufficient recruitment data for the calculation of NNS and funding source and type of intervention.
conclusionRCTs reporting recruitment data in primary care suggest that once screened for eligibility and found to match inclusion criteria patients are likely to be randomized. This finding needs to be treated with caution as it may represent inadequate identification or reporting of the eligible population. A substantial minority of RCTs did not provide sufficient information about the patient recruitment process.
Indexed as
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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.