Recent advances in lung function standard value prediction equations: Comparison with the Global Lung Initiative...

To accurately interpret lung function test (LFTs) results, it is necessary to appropriately select the lung function reference value prediction equation implemented in the measuring equipment of each medical institution. The American Thoracic Society (ATS) and European Respiratory Society (ERS) task force, known as the Global Lung Function Initiative (GLI), recommends the use of a lung function standard value prediction equation that can calculate continuous standard values across a wide age range. Generalized additive models for location, scale, and shape (GAMLSS) are statistical techniques used to create accurate percentiles for a wide age range. This prediction equation was created using the lambda, mu, and sigma (LMS) method, a subtype of a statistical method known as generalized additive models for location, scale, and shape (GAMLSS). Lung function equations created using the LMS method can be used to calculate the z-score, which can contribute to a more accurate interpretation of the results. As for the contents of this review, an overview of the development of equations for predicting lung function using GAMLSS, such as spirometry, diffusion capacity, and static lung volume, is provided in the first portion of this review. The second section of this review compiles the statistical knowledge required to develop lung function reference-value prediction algorithms based on GAMLSS. This section briefly explains how to calculate the z-score and provides advice on addressing ethnic diversity in the lung function standard value prediction equations.