The 4 Factors in the BODE Index

Four different factors are evaluated as part of the BODE index. The reason for this index is that each of these factors can make some prediction about the prognosis of COPD, but added together the prediction is more accurate. The letters stand for:

Body Mass Index (BMI) is a calculation made by comparing height vs weight. Airway Obstruction: Airway obstruction is measured by evaluating FEV1 — the amount of air that can be forcefully exhaled in one second after a deep breath. Dyspnea refers to the degree of breathlessness someone experiences while living with COPD. Exercise tolerance refers to how well someone does on a 6-minute walk test.

Let’s look at each of these measures separately, and then put them together in measuring the BODE index.

B - Body Mass Index

BMI is a calculation that is made by comparing height in meters by weight in kilograms. There are calculators for determining BMI, as well as tables. BMI is an estimate of how overweight or underweight a person is. With COPD, being underweight or malnourished is a poor sign when it comes to prognosis.

O - Airway Obstruction

Forced expiratory volume in one second (FEV1) is a measure of the amount of air that can be forcefully exhaled in one second. The forced vital capacity (FVC) measurement shows the amount of air a person can forcefully and quickly exhale after taking a deep breath. The ratio FEV1/FVC, therefore, represents the total percentage of air that can be exhaled in one second. A normal FEV1/FVC ratio in adults is 0.70 or greater, while in children a normal ratio is 0.80 or greater. If there is an obstruction in the airways slowing or preventing this rapid exhalation of air, the ratio decreases.

D - Dyspnea

Dyspnea is the term that refers to the physical sensation of shortness of breath or breathlessness. Doctors may distinctions based on what someone may need to do —how active they are—before they become short of breath. At first, a person may only become breathless if they walk 5 miles. Later on, in COPD a person may note breathlessness with any movement at all. The modified Medical Research Council dyspnea scale (mMRC) is frequently used to evaluate dyspnea related to COPD. In this measurement, breathlessness is measured on a scale of 0 to 4:

mMRC Grade 0: Breathless with only strenuous exercisemMRC Grade 1: Short of breath when hurrying or walking up a slight hillmMRC Grade 2: Walks slower than peers on level ground because of breathlessness or has to stop for breath when walking at own pacemMRC Grade 3: Stops for breath after walking 100 meters or after a few minutesmMRC Grade 4: Too breathless to leave the house or breathless when dressing or undressing

E - Exercise Tolerance

Exercise tolerance refers to how active someone is able to be with the restrictions put forth by their lung disease. A test called a 6-minute walk test is used to obtain the value for the BODE index.

Values and Ranges

The following values are those that can be assigned to determine the BODE index. Note that a score can range from 0 to 10 total depending on how these add up.

Survival Rates

Approximate 4-year survival rates based on the BODE index point system above is as follows:

0-2 points: 80%3-4 points: 67%5-6 points: 57%7-10 points: 18%

Life Expectancy

The BODE index is one generalized measurement but survival varies tremendously when talking about individual people. Learn about some of the factors which influence COPD expectancy along with what you can do to improve your personal survival chance. If your disease is worsening, you may wish to learn as well about what you can expect with end-stage COPD.

NOTE: The BODE Index is meant to be used as a tool, for informational purposes only. It should not replace the advice of a healthcare professional.

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