Aligning Lung Function Equipment and Reference Values in Adults.

Area of Science:

• Pulmonary Function Testing
• Biomedical Engineering
• Clinical Laboratory Science

Background:

• Introducing new equipment or reference equations in lung function labs can cause systematic z-score deviations.
• Local population and equipment variations contribute to these discrepancies.

Purpose of the Study:

• To propose and validate a practical method for aligning lung function reference equations with laboratory-specific equipment.
• To ensure accurate and reliable pulmonary function test results across different equipment and populations.

Main Methods:

• Utilized two equipment transition cases as a testbed.
• Lung function testing was performed on a control group of 40 young adults (20 male/20 female, 20-30 years old).
• The lambda-mu-sigma (LMS) method was employed to adapt reference values by adjusting the M coefficient for indices with z-scores exceeding ±0.5.

Main Results:

• Following a transition reducing instrumental dead space, the lung clearance index z-score shifted from -1.9 to -0.1 after adaptation.
• Similar alignment was observed for standard lung function equipment transitions in both control and a wider age-ranging test group (81 subjects, 20-80 years).

Conclusions:

• A method for aligning local equipment with external reference values or post-equipment change data was proposed and verified.
• Measuring a small young adult group is key to identifying indices needing adaptation, enabling laboratory-specific reference values applicable across all ages.