For Publishers
DiscoveryMetadataPeer reviewHostingPublishing
For Researchers
JoinPublishReviewCollect
Register
Blog
About
Search
Advanced search
My ScienceOpen
Search
For Publishers
For Researchers
Blog
About
7
views
10
references
 Top references
cited by
0
    
0 reviews
 Review
0
comments
 Comment
0
recommends
+1 Recommend
0 collections
    0
    shares
      226
      similar
       All similar
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Group-sequential analysis may allow for early trial termination: illustration by an intra-observer repeatability study

      brief-report

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Background

          Group-sequential testing is widely used in pivotal therapeutic, but rarely in diagnostic research, although it may save studies, time, and costs. The purpose of this paper was to demonstrate a group-sequential analysis strategy in an intra-observer study on quantitative FDG-PET/CT measurements, illuminating the possibility of early trial termination which implicates significant potential time and resource savings.

          Methods

          Primary lesion maximum standardised uptake value (SUVmax) was determined twice from preoperative FDG-PET/CTs in 45 ovarian cancer patients. Differences in SUVmax were assumed to be normally distributed, and sequential one-sided hypothesis tests on the population standard deviation of the differences against a hypothesised value of 1.5 were performed, employing an alpha spending function. The fixed-sample analysis ( N = 45) was compared with the group-sequential analysis strategies comprising one (at N = 23), two (at N = 15, 30), or three interim analyses (at N = 11, 23, 34), respectively, which were defined post hoc.

          Results

          When performing interim analyses with one third and two thirds of patients, sufficient agreement could be concluded after the first interim analysis and the final analysis. Other partitions did not suggest early stopping after adjustment for multiple testing due to one influential outlier and our small sample size.

          Conclusions

          Group-sequential testing may enable early stopping of a trial, allowing for potential time and resource savings. The testing strategy must, though, be defined at the planning stage, and sample sizes must be reasonably large at interim analysis to ensure robustness against single outliers. Group-sequential testing may have a place in accuracy and agreement studies.

          Electronic supplementary material

          The online version of this article (10.1186/s13550-017-0328-6) contains supplementary material, which is available to authorized users.

          Related collections

          Most cited references10

          • Record: found
          • Abstract: found
          • Article: found
          Is Open Access

          Statistical Methods Used to Test for Agreement of Medical Instruments Measuring Continuous Variables in Method Comparison Studies: A Systematic Review

          Rafdzah Zaki, Awang M Bulgiba, Roshidi Ismail … (2012)
          Background Accurate values are a must in medicine. An important parameter in determining the quality of a medical instrument is agreement with a gold standard. Various statistical methods have been used to test for agreement. Some of these methods have been shown to be inappropriate. This can result in misleading conclusions about the validity of an instrument. The Bland-Altman method is the most popular method judging by the many citations of the article proposing this method. However, the number of citations does not necessarily mean that this method has been applied in agreement research. No previous study has been conducted to look into this. This is the first systematic review to identify statistical methods used to test for agreement of medical instruments. The proportion of various statistical methods found in this review will also reflect the proportion of medical instruments that have been validated using those particular methods in current clinical practice. Methodology/Findings Five electronic databases were searched between 2007 and 2009 to look for agreement studies. A total of 3,260 titles were initially identified. Only 412 titles were potentially related, and finally 210 fitted the inclusion criteria. The Bland-Altman method is the most popular method with 178 (85%) studies having used this method, followed by the correlation coefficient (27%) and means comparison (18%). Some of the inappropriate methods highlighted by Altman and Bland since the 1980s are still in use. Conclusions This study finds that the Bland-Altman method is the most popular method used in agreement research. There are still inappropriate applications of statistical methods in some studies. It is important for a clinician or medical researcher to be aware of this issue because misleading conclusions from inappropriate analyses will jeopardize the quality of the evidence, which in turn will influence quality of care given to patients in the future.
          Article 0 comments Cited 89 times – based on 0 reviews     Review now
            Bookmark
            • Record: found
            • Abstract: not found
            • Article: not found

            The Design and Analysis of Sequential Clinical Trials.

            J. Whitehead (1997)
            Article 0 comments Cited 48 times – based on 0 reviews     Review now
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              [18F]Fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET)/Computed Tomography (CT) in Suspected Recurrent Breast Cancer: A Prospective Comparative Study of Dual-Time-Point FDG-PET/CT, Contrast-Enhanced CT, and Bone Scintigraphy.

              Lisbet Larsen, Henrik Petersen, Oke Gerke … (2016)
              To prospectively investigate the diagnostic accuracy of [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) with dual-time-point imaging, contrast-enhanced CT (ceCT), and bone scintigraphy (BS) in patients with suspected breast cancer recurrence.
              Article 0 comments Cited 28 times – based on 0 reviews     Review now
                Bookmark
                All references

                Author and article information

                Contributors
                Oke Gerke:
                ORCID: http://orcid.org/0000-0001-6335-3303
                +45 3017 1885 , oke.gerke@rsyd.dk
                Mie H. Vilstrup: mie.holm.vilstrup@rsyd.dk
                Ulrich Halekoh: uhalekoh@health.sdu.dk
                Malene Grubbe Hildebrandt: malene.grubbe.hildebrandt@rsyd.dk
                Poul Flemming Høilund-Carlsen: pfhc@rsyd.dk
                Journal
                Journal ID (nlm-ta): EJNMMI Res
                Journal ID (iso-abbrev): EJNMMI Res
                Title: EJNMMI Research
                Publisher: Springer Berlin Heidelberg (Berlin/Heidelberg )
                ISSN (Electronic): 2191-219X
                Publication date (Electronic): 26 September 2017
                Publication date PMC-release: 26 September 2017
                Publication date Collection: 2017
                Volume: 7
                Electronic Location Identifier: 79
                Affiliations
                [1 ]ISNI 0000 0004 0512 5013, GRID grid.7143.1, Department of Nuclear Medicine, , Odense University Hospital, ; J.B. Winsløws Vej 4, 5000 Odense C, Denmark
                [2 ]ISNI 0000 0001 0728 0170, GRID grid.10825.3e, Centre of Health Economics Research, , University of Southern Denmark, ; Campusvej 55, 5230 Odense M, Denmark
                [3 ]ISNI 0000 0001 0728 0170, GRID grid.10825.3e, Epidemiology, Biostatistics and Biodemography, , University of Southern Denmark, ; J.B. Winsløws Vej 9b, 5000 Odense C, Denmark
                [4 ]ISNI 0000 0001 0728 0170, GRID grid.10825.3e, Department of Clinical Research, , University of Southern Denmark, ; Winsløwparken 19, 5000 Odense C, Denmark
                Author information
                http://orcid.org/0000-0001-6335-3303
                Article
                Publisher ID: 328
                DOI: 10.1186/s13550-017-0328-6
                PMC ID: 5615083
                PubMed ID: 28952076
                SO-VID: bcc801d1-917b-4fda-bbe3-37a7600e1756
                Copyright © © The Author(s). 2017
                License:

                Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License ( http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

                History
                Date received : 14 June 2017
                Date accepted : 19 September 2017
                Categories
                Subject: Short Communication
                Custom metadata
                issue-copyright-statement © The Author(s) 2017

                ScienceOpen disciplines: Radiology & Imaging
                Keywords: agreement,bland-altman plot,repeatability,reproducibility,sample size
                Data availability:
                ScienceOpen disciplines: Radiology & Imaging
                Keywords: agreement, bland-altman plot, repeatability, reproducibility, sample size

                Comments

                Comment on this article