Bland-Altman analysis: A paradigm to understand correlation and agreement

The rapid increase in the number of new laboratory methods has led to the necessity of reliable verification methods. Validation of a new measurement method for application to medical practice requires comparison with gold standard techniques. The Bland-Altman analysis is a frequently applied technique in studies that investigate the agreement between two methods of the same medical measurement. In this review, potential areas of usage of Bland-Altman analysis is elaborated from a clinical viewpoint, and possible pitfalls in study designs are discussed in statistical perspective.