## What are predicted values in spirometry?

The Predicted column compares the actual total volume breathed out during the test to an average of the normal total volume for a person of the same gender, height, and age. This is expressed as a percentage, with normal test values falling between 80% and 120% of the average (predicted) values.

## What are normal values for spirometry test results?

SPIROMETRY TEST NORMAL ABNORMAL
FVC and FEV1 Equal to or greater than 80% 70-79% 60-69% less than 60%
FEV1/FVC Equal to or greater than 70% 60-69% 50-59% less than 50%

What is predicted lung function?

What will the results look like? Lung volume is measured in litres. Your predicted total lung capacity (TLC) is based on your age, height, sex and ethnicity, so results will differ from person to person. Normal results typically range between 80% and 120% of the prediction.

### What is FEV1 predicted value?

Your FEV1 value is an important part of evaluating chronic obstructive pulmonary disease (COPD) and monitoring progression of the condition….How is FEV1 used to stage COPD?

GOLD Stage of COPD Percentage of predicted FEV1 value
mild 80%
moderate 50%–79%
severe 30%–49%
very severe Less than 30%

### What is predicted FEV1?

FEV1 is calculated by converting the spirometer reading to a percentage of what would be predicted as normal based on standardization that’s calculated for your height, age, gender, and race. For example, your FEV1 could be 80% of your predicted value.

How many mL is normal on a spirometer?

The typical value for a young adult male of normal size is about 3000 mL. C. The expiratory reserve volume, ERV, is the additional volume of air that can be expired after a normal or tidal expiration. A typical value is about 1100 mL for a young adult male.

#### What is FEV1 percent predicted?

This represents the percentage of your lung capacity that you can expel in one second. The higher your percentage, the larger your lung capacity and the healthier your lungs. Your doctor will diagnose COPD if your FEV1/FVC ratio falls below 70 percent of the predicted value.

#### How do you predict FVC and FEV1?

A very strong, age-independent linear relationship between FEV1 and FVC was found in healthy individuals (the correlation coefficient r = 0.96). It can be described with the equation FEV1 = A x FVC + C, where A = 0.84 and C = −0.23 (−0.36) for females (males).

How do you calculate predicted FEV1 FVC?

The FEV1/FVC ratio is the ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lungs….Formulas

1. FEV1 = Race x 1.08 x [(0.0395 x Height) – (0.025 x Age) – 2.6]
2. FVC = Race x 1.15 x [(0.0443 x Height) – (0.026 x Age) – 2.89]
3. FEV1/FVC Ratio = FEV1 / FEVC.

## How do you interpret spirometry results?

Your result is considered “normal” if your score is 80 percent or more of the predicted value. Spirometry measures two key factors: expiratory forced vital capacity (FVC) and forced expiratory volume in one second (FEV1). Your doctor also looks at these as a combined number known as the FEV1/FVC ratio.