Prediction equations for spirometry in adults from northern India

Area of Science:

• Pulmonary Medicine
• Respiratory Physiology
• Clinical Epidemiology

Background:

• Existing Indian spirometry prediction equations are outdated, using obsolete equipment and standards.
• Population lung health may have changed, questioning the validity of older equations.

Purpose of the Study:

• Develop updated spirometry prediction equations for North Indian adults.
• Utilize the 2005 American Thoracic Society/European Respiratory Society (ATS/ERS) standardization guidelines.

Main Methods:

• Spirometry performed on 685 healthy non-smoking adults (≥18 years).
• Equations developed using multiple linear regression on a training set (70%) and validated on a test set (30%).
• Compared new equations with those from the 1960s.

Main Results:

• New equations developed for FVC, FEV1, FEV1/FVC, and FEF75, separately for males and females.
• Significant differences in spirometry parameters between males and females noted.
• Current equations predict substantially higher FVC than 1960s equations, particularly in older adults.

Conclusions:

• Validated spirometry prediction equations for North Indian adults are now available.
• Findings suggest improved lung health in middle-aged and elderly Indian populations.
• These equations will enhance the evaluation of respiratory diseases in India.