Comparing Spirometric Reference Values From Childhood to Old Age Estimated by LMS and Linear Regression Models

Area of Science:

• Pulmonary Medicine
• Biostatistics
• Population Health

Background:

• Accurate lung function testing requires appropriate reference values.
• The LMS (lambda, mu, sigma) procedure enables continuous population analysis, bridging childhood and adulthood.
• LMS calculations offer precise estimates of averages, dispersion, and lower limits of normality.

Purpose of the Study:

• To compare lung function reference equations derived using the LMS method with those from standard multiple linear regression.
• To evaluate LMS-derived equations against international Global Lung Function Initiative (GLI) equations for a Mexican population.

Main Methods:

• Compiled data from 9835 healthy Mexican residents aged 8-80 years.
• Applied the LMS procedure and multiple linear regression to generate reference equations.
• Utilized R software for statistical modeling.

Main Results:

• LMS models demonstrated a slightly better statistical fit compared to linear regression models.
• Residuals from LMS models showed a median closer to zero and smaller dispersion.
• Average spirometric values for the Mexican population were higher than GLI predictions.

Conclusions:

• Continuous reference equations using the LMS technique offer a slightly improved fit for the Mexican population.
• The LMS method provides a robust approach for establishing age- and sex-specific lung function norms.