Han, O., Tan, H.W., Julious, S. orcid.org/0000-0002-9917-7636 et al. (5 more authors) (2022) A descriptive study of samples sizes used in agreement studies published in the PubMed repository. BMC Medical Research Methodology, 22 (1). 242. ISSN 1471-2288
Abstract
Introduction
A sample size justification is required for all studies and should give the minimum number of subjects to be recruited for the study to achieve its primary objective. The aim of this review is to describe sample sizes from agreement studies with continuous or categorical endpoints and different methods of assessing agreement, and to determine whether sample size justification was provided.
Methods
Data were gathered from the PubMed repository with a time interval of 28th September 2018 to 28th September 2020. The search returned 5257 studies of which 82 studies were eligible for final assessment after duplicates and ineligible studies were excluded.
Results
We observed a wide range of sample sizes. Forty-six studies (56%) used a continuous outcome measure, 28 (34%) used categorical and eight (10%) used both. Median sample sizes were 50 (IQR 25 to 100) for continuous endpoints and 119 (IQR 50 to 271) for categorical endpoints. Bland–Altman limits of agreement (median sample size 65; IQR 35 to 124) were the most common method of statistical analysis for continuous variables and Kappa coefficients for categorical variables (median sample size 71; IQR 50 to 233). Of the 82 studies assessed, only 27 (33%) gave justification for their sample size.
Conclusions
Despite the importance of a sample size justification, we found that two-thirds of agreement studies did not provide one. We recommend that all agreement studies provide rationale for their sample size even if they do not include a formal sample size calculation.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Author(s) 2022. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. |
Keywords: | Agreement; Design; Method Comparison; Sample size; Test-retest |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Medicine, Dentistry and Health (Sheffield) > School of Health and Related Research (Sheffield) > ScHARR - Sheffield Centre for Health and Related Research |
Funding Information: | Funder Grant number NATIONAL INSTITUTE FOR HEALTH RESEARCH nan DEPARTMENT OF HEALTH AND SOCIAL CARE UNSPECIFIED DEPARTMENT OF HEALTH AND SOCIAL CARE UNSPECIFIED SHEFFIELD TEACHING HOSPITALS NHS FOUNDATION TRUST SIRCF2020/21-GoodacreWaltersSI NATIONAL INSTITUTE FOR HEALTH RESEARCH nan |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 04 Oct 2022 13:19 |
Last Modified: | 04 Sep 2024 20:07 |
Status: | Published |
Publisher: | Springer Science and Business Media LLC |
Refereed: | Yes |
Identification Number: | 10.1186/s12874-022-01723-5 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:191134 |