Društvo Atopijski dermatiits
Atopic Dictionary

Tiffeneau's index

The Tiffeneau index (TI) is the ratio between FEV1 and FVC. In spirometry, we measure the forced vital capacity (FVC), which represents the volume of exhaled air after a maximum long inhalation. When performing FVC, the forced expiratory volume in the first second (FEV1) is also measured, which is the volume of air that a person exhales in the first second of FVC. The ratio between FEV1 and FVC is called the Tiffeneau index, which in a healthy person is above 75%, meaning that a person with healthy lungs can exhale 3/4 of the air from the lungs in the first second of forced exhalation. These values vary depending on various factors, such as age, gender, and body height and weight.