[Adjustment of several spirometric reference equations to a population-based sample in Mexico]

Area of Science:

• Pulmonary Medicine
• Clinical Physiology

Background:

• Accurate spirometry reference equations are crucial for diagnosing respiratory diseases.
• Existing equations may not accurately reflect lung function in diverse populations, including Mexicans.

Purpose of the Study:

• To evaluate and compare the fit of various forced spirometry reference equations within a Mexican population sample.
• To identify the most appropriate equations for predicting lung function in Mexico City adults.

Main Methods:

• Compared spirometric values (FEV1, FVC) from 225 healthy adults (≥40 years) in Mexico City to multiple reference equations.
• Calculated differences between observed and expected values, performed concordance analysis, and determined the percentage of subjects below the lower limit of normal.

Main Results:

• NHANES III (for Mexican-Americans/Euro-Americans) and PLATINO equations showed the best fit for FEV1 and FVC.
• Knudson equations underestimated values, while Cruz-Mérida overestimated them.
• The PLATINO reference values resulted in a percentage of subjects below the lower limit of normal closest to the expected 5%.

Conclusions:

• Recommends the use of NHANES III (for Mexican-Americans or European-Americans) and PLATINO reference values for spirometry in Mexico.
• These equations provide a better fit for predicting lung function in the studied Mexican population.