[Repeatability of spirometry's expiratory flows].

Area of Science:

• Pulmonary Function Testing
• Respiratory Medicine
• Medical Diagnostics

Context:

• Spirometry is crucial for assessing lung function.
• Ensuring the quality of spirometry measurements is essential for accurate diagnosis.
• Established criteria for spirometry acceptability and repeatability guide quality assessment.

Purpose:

• To evaluate the repeatability of quality A spirometry measurements.
• To determine if the consensus criterion of < 0.150 L for repeatability is met in high-quality spirometry.
• To validate the < 0.150 L repeatability criterion for clinical use.

Summary:

• This study analyzed 630 spirometry curves from 210 subjects (age 60 ± 15 years, 53.8% female).
• Repeatability was assessed using mean difference (bias) and intraclass correlation coefficient (ICC) for forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC).
• Results showed excellent repeatability, with differences < 0.150 L and high ICC values (e.g., FEV1 1 vs. 2 maneuver: ICC 0.997), validating the criterion.

Impact:

• The findings validate the < 0.150 L repeatability criterion for quality A spirometry.
• This supports the consistent and reliable use of spirometry in clinical practice for diagnosing and monitoring respiratory diseases.
• Accurate spirometry enhances patient management and treatment efficacy for conditions like COPD.