Evidence map›Paper›PMID 27184938›Full record

ArticleBiometrical journal. Biometrische Zeitschrift2017

Determination of the optimal sample size for a clinical trial accounting for the population size.

Nigel Stallard, Frank Miller, Simon Day, Siew Wan Hee, Jason Madan, Sarah Zohar, Martin Posch

Abstract read
In one paragraph

Article in Biometrical journal. Biometrische Zeitschrift, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 15 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
15citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from 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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

15 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Bayesian Approaches for Confirmatory Trials in Rare Diseases: Opportunities and Challenges.International journal of environmental research and public health · 2021
    Pooled it
  2. Review
  3. Article
  4. Review
  5. Review
  6. Article
  7. Article
  8. Bayesian Methods in Regulatory Science.Statistics in biopharmaceutical research · 2020
    Article
  9. Article
  10. Vinpocetine regulates levels of circulating TLRs in Parkinson's disease patients.Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2019
    Article
  11. DELTATrials · 2018
    Article
  12. DELTABMJ (Clinical research ed.) · 2018
    Article
  13. Review
  14. Article
  15. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Nigel StallardStatistics and Epidemiology, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK.
Frank MillerDepartment of Statistics, Stockholm University, Stockholm, Sweden.
Simon DayClinical Trials Consulting and Training Limited, Buckingham, UK.
Siew Wan HeeStatistics and Epidemiology, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK.
Jason MadanClinical Trials Unit, Warwick Medical School, University of Warwick, Coventry, UK.
Sarah ZoharINSERM, U1138, team 22, Centre de Recherche des Cordeliers, Université Paris 5, Université Paris 6, Paris, France.
Martin PoschSection of Medical Statistics, CeMSIIS, Medical University of Vienna, Austria.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The problem of choosing a sample size for a clinical trial is a very common one. In some settings, such as rare diseases or other small populations, the large sample sizes usually associated with the standard frequentist approach may be infeasible, suggesting that the sample size chosen should reflect the size of the population under consideration. Incorporation of the population size is possible in a decision-theoretic approach either explicitly by assuming that the population size is fixed and known, or implicitly through geometric discounting of the gain from future patients reflecting the expected population size. This paper develops such approaches. Building on previous work, an asymptotic expression is derived for the sample size for single and two-arm clinical trials in the general case of a clinical trial with a primary endpoint with a distribution of one parameter exponential family form that optimizes a utility function that quantifies the cost and gain per patient as a continuous function of this parameter. It is shown that as the size of the population, N, or expected size, N∗ in the case of geometric discounting, becomes large, the optimal trial size is O(N1/2) or O(N∗1/2). The sample size obtained from the asymptotic expression is also compared with the exact optimal sample size in examples with responses with Bernoulli and Poisson distributions, showing that the asymptotic approximations can also be reasonable in relatively small sample sizes.

Indexed as

Population DensityBayes TheoremClinical Trials as TopicHumansPoisson DistributionSample SizeBayesianClinical trial designDecision theoryExponential family formOptimal sample size

Identifiers

PMID27184938
PMCPMC5516263

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Registered trials

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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.