Abstract
BACKGROUND: Method comparison studies are conducted to examine the level of agreement between two instruments measuring physiological continuous parameters. The inclusion of repeated measurements in such studies poses additional challenges. The Bland & Altman limits of agreement (LOA) approach has been adapted to account for the correlation between repeated measurements and is widely used in method comparison studies. Alternate statistical methods are not always appropriate for the analysis of such data, and there is a paucity of evidence and guidelines pertaining to statistical methods that inform the analysis of method comparison studies that include repeated measurements. This scoping review aimed to identify methodological publications that propose statistical methods to inform the analysis of method comparison studies that include repeated measurements of continuous clinical data and that may be compared with the LOA method. METHODS: Six online databases were searched from inception to November 2022 using a peer-reviewed search strategy. Searching of grey literature and books, as well as backward citation searching were performed to identify additional sources of evidence. Screening and data abstraction were done by two independent reviewers. Results were synthesized narratively. RESULTS: Twenty-nine publications were included in this review. Thirty-two independent statistical methods were identified from the included publications, including variants of the LOA method. Four included publications compared findings from different versions of the LOA method. Four different approaches to handling repeated measurements in the context of method comparison studies were identified and were used to group findings from the included publications. Reported strengths and limitations of the LOA method were summarized. CONCLUSION: This scoping review provides a synthesis of existing statistical approaches to inform the analysis of method comparison studies with repeated measurements of clinical data, as well as how the various statistical methods perform when compared with various version of the LOA method. Based on the findings, it is generally advisable to consider using adjusted LOAs or modified mixed-effect LOAs in analyzing method comparison studies with repeated measurements. TRIAL REGISTRATION: The protocol was registered on Open Science Framework ( https://osf.io/4p8ut ).