gms | German Medical Science

Background: Bland-Altman Limits of Agreement (BA LoA) are a popular and widespread means of analyzing the agreement of two methods, instruments, or raters in quantitative outcomes. Agreement analysis could be reported as stand-alone research articles but are more often than not conducted as a minor quality assurance project in a subgroup of patients in a larger diagnostic accuracy study, clinical trial, or epidemiological survey, leading to brief descriptions and few details in the main report [1]. To this end, reporting items for Bland-Altman analysis have been proposed in different medical areas.The aim of this study was to identify such reporting standards proposals for BA agreement analysis, consolidate experiences across fields, and exemplify reporting standards for BA LoA by means of a recently conducted interrater Bland-Altman analysis from our institution.

Methods: MEDLINE/PubMed was searched for (((reporting) OR checklist)) AND (((("method comparison") OR bland-altman) OR (bland AND altman)) OR agreement). All papers that proposed a list of items for standardizing BA plots were included, irrespective of article type (systematic reviews, narrative reviews, original articles, commentaries, editorials, letters, and case studies). The latest publication date included was March 3, 2020. The Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement was consulted but could only be applied to a limited extent due to the methodological nature of papers to be included in this review.

Results: The literature search resulted in 5,600 hits. Seven proposals were identified, three of which were derived from reviewing anesthesia journals. Four studies leaned on publications within 2-year time frames, and the number of included publications varied from 0 to 394 (median: 50). Across included studies, 16 reporting items were proposed. Broad consensus was seen for the a priori establishment of acceptability benchmarks, the estimation of repeatability of measurements, description of the data structure, visual assessment of the normality and homogeneity assumption, and plotting and numerically reporting of both bias and Bland-Altman Limits of Agreement including respective 95% confidence intervals. The work of Abu-Arafeh et al. turned out to be the most comprehensive and prudent list, identifying 13 key items for reporting [2].

Conclusion: The unbowed popularity of BA plots (as judged by the number of citations of the seminal papers [3], [4] and a pedagogical update [5]), the limited extent as to which BA plots are reported and interpreted in the literature, and the associated need for standardization as evidently expressed by the included proposals obligate researchers to more diligence and warrant journal editors to consider the work of Abu-Arafeh et al. [2] as an essential supplement to GRRAS [1] with respect to statistical analysis of agreement with BA plots.

The authors declare that they have no competing interests.

The authors declare that an ethics committee vote is not required.