Pulmonary Function Test: Spirometry

The spirometry test or pulmonary function test measures Forced Expiratory Volume in 1 second (FEV1) and the Forced Vital Capacity (FVC) which are used in determining the COPD stage the patient is in using either the GOLD System or the BODE Index. The doctor then uses the COPD stage the patient is in for predicting their longevity. Determining the longevity of a COPD patient is very difficult since so many factors play a part in determining their life expectancy.

GOLD COPD Staging System

There are currently two methods of determining a patient’s COPD stage. The first, and most commonly used method is called the GOLD System. GOLD is an acronym that stands for the Global Initiative for Obstructive Lung Disease.

The Gold System uses only one metric in determining the stage of a COPD patient, FEV1. FEV1 is the Forced Expiratory Volume in 1 second as determined by a Pulmonary Function Test, generally the Spirometry test.

A COPD patient’s stage is then determined by the following:

Stage I Mild COPD FEV1 ≥ 80% normal
Stage II Moderate COPD 50% ≤ FEV1 < 80% normal
Stage III Severe COPD 30% ≤ FEV1 < 50% normal
Stage IV Very Severe COPD FEV1 < 30% normal

So in the GOLD System of staging for COPD, you are in Stage I if your forced expiratory volume in 1 second (FEV1) is greater than or equal to 80% of your total exhaled breath which is referred to as your “Forced Vital Capacity” or FVC.

You may also see this expressed as FEV1/FVC in which case the number will be in decimal form. For Stage I COPD the number would be expressed as 0.80. So charts that use this FEV1/FVC would show Stage I COPD as: FEV1/FVC < 0.70 or 0.80 of normal.

The problem with the GOLD System is that it is just not accurate enough in predicting life expectancy or future symptoms. GOLD only considers the degree of airflow obstruction when other factors may play a big role in determining the actual life expectancy of COPD patients that are relying solely on medications when treating their COPD.

Alternative treatments are available that can greatly affect and improve a COPD patient’s life expectancy. Those alternative COPD treatments are covered in detail on the Alternative COPD Treatments page of this web site.

Below is a link to a complete description of the GOLD System. It is a downloadable PDF if you would like additional informaiton regarding the GOLD System of staging COPD.

Global Initiative for Chronic Obstructive Lung Disease

The BODE Index COPD Staging

The problem with using the GOLD System in predicting the life expectancy of COPD patients who are relying solely on medications for the treatment of their COPD is that it does not take into account the Body Mass Index of the COPD patient, their degree of breathlessness or the amount and degree of exercise the COPD patient can perform. A newer and much more accurate system for staging COPD patients was developed called the BODE Index.

BODE is also an acronym which stands for BMI (Body Mass Index), Obstruction, Dyspnea (breathlessness), Exercise Capacity (health index). The BODE Index uses 4 metrics in determining the stage of a COPD patient.

Determining Your BODE Index Score

The BODE Index score is calculated by adding the 4 metrics mentioned above. You will see below that the lower your BODE Index score, the longer your life expectancy. Put another way, the higher your BODE Index score means the further your COPD has progressed. Theoretically, if a COPD patient used alternative treatments that resulted in a full recovery, their BODE Index score would gradually decrease until it reached “0.” This occurred with my mother after the alternative treatments were implemented into her daily regimen.

We currently have patients in our COPD Focus Group who are scoring a “2” on their BODE Index score. Most of them were scoring a “9” or “10” a year earlier.

Body Mass Index

The first of 4 metrics used in BODE Index scoring is the body mass index. Most people have heard of body mass index or BMI but are unsure how it is calculated.

BMI or Body Mass Index is calculated by dividing your weight in kilograms by the square of your height in meters.

BMI = weight (Kg)/height (m2) If you need the calculation for BMI in pounds and inches here it is:

Calculate BMI by dividing weight in pounds (lbs) by height in inches (in2) squared and multiplying by a conversion factor of 703.


Weight = 150 lbs
Height = 5'5" or 65"

Calculation: [150 ÷ (65)2] x 703 = 24.96

When we incorporate the body mass index calculation into the BODE Index score we use the following scoring criteria:

Body Mass Index (BMI)

0 Points: BMI >21 (Body Mass Index greater than 21.)
1 Points: BMI ≤ 21 (Body Mass Index less than or equal to 21.)

So we see for our example above with a calculated BMI of 24.96 we would add “0” points to our BODE Index score.

For some people this seems backwards. It seems like you should add 1 point if your body mass index is above 21 and add 0 points if it is less than or equal to 21. The reason it is the opposite of what you may have thought it would be is that COPD patients generally lose weight as their COPD progresses. Therefore, in general, the lighter they are or the more weight they have lost, the worse off they are and the more their COPD has progressed.

Pulmonary Obstruction

The second metric utilized in calculating the BODE Index score is “obstruction” or more specifically, pulmonary obstruction. The more obstruction a COPD patient has, the lower their FEV1 or “Forced Expiratory Volume in 1 second.” FEV1 is generally determined by a Spirometry test done in the doctor’s office. Remember that this is the only metric used in determining your COPD stage when using the GOLD System.

Use the following criteria when determining the value you should add to your BODE Index score:

0 Points: FEV1 >64%
1 Points: FEV1 50-64%
2 Points: FEV1 36-49%
3 Points: FEV1 <36%

MRC Dypsnea Scale

Dypsnea means “shortness of breath.” An episode of extreme shortness of breath is called an “exacerbation.” You will see both of these words thorughout the information detailing COPD, emphysema, chronic bronchitis, bronchiectasis and asthma.

The MRC Breathlessness Scale

The MRC Breathlessness Scale is to be used by you when assigning the correct grade number to your own breathlessness. You will, of course, want to give yourself an honest assessment. You may also want to discuss this number with your doctor and get their opinion. After assigning a “Grade” to your breathlessness or dypsnea, then use the following criteria in determining what number or value you should add to your BODE Index score.

MRC Dyspnea Index

0 Points: Dyspnea Index Grade 0-1
1 Points: Dyspnea Index Grade 2
2 Points: Dyspnea Index Grade 3
3 Points: Dyspnea Index Grade 4-5

Dyspnea is difficult to quantify but it is necessary if the symptoms of a particular group are to be summarized and compared with others.

Researchers addressed this problem when studying the respiratory problems of Welsh coal miners at the Medical Research Council Pneumoconiosis Unit in the 1940s.

They devised a short questionnaire that allowed a numeric value to be placed on each subject's exercise capacity.

The questions were first published in 1952 and rapidly developed into the (Medical Research Council) MRC Dypsnea Scale. They have been in widespread use since that time.

Exercise Capacity

The fourth and final metric included in the BODE Index score calculation is exercise capacity. This is determined by measuring the distance the COPD patient can walk in 6 minutes. This is easily done at Pulmonary Rehab on a treadmill.

Points are assigned with regards to the total distance the COPD patient can cover in 6 minutes.

Six-Minute Walk Test:

0 Points: Walks >349 meters
1 Points: Walks 250-349 meters
2 Points: Walks 150-249 meters
3 Points: Walks <150 meters

We can see that when the COPD patient can walk more than 349 meters or about 3 and a half football fields, in 6 minutes we add “0” points to their BODE Index score. Remember a “0” BODE Index score total means a full recovery.

Calculating the BODE Index Score

Now that we have all 4 metrics, we can simply add them together and arrive at our BODE Index score. See the following example below for clarification.

John Doe
BMI = 19
Obstruction or FEV1 = 40%
dypsnea Grade = 4
6 minute walk distance = 160 meters

We calculate John Doe’s BODE Index score by adding the following:

BMI = 19 which if we look at the criteria we see that this will add a value of “1” to his BODE Index score.

His FEV1 = 40% so we look at our criteria and see that this will add a value of “2” to his BODE Index score.

His MRC Dypsnea Grade was a “4” which adds a value of “3” to his BODE Index score.

His exercise capacity was 160 meters in 6 minutes which adds a value of “2” to his BODE Index score.

John Doe’s BODE Index score is then calculated by adding the values for each metric as follows:

Value for BMI + Value for FEV1 + Value for Dypsnea + Value for Exercise Capacity

The values for John’s metrics are shown below with his BODE Index score calculated as an 8.

1 + 2 + 3 + 2 = 8

The medical industry uses this BODE Index score when predicting the longevity of a COPD patient. Remember, these predictions assume the COPD patient will rely solely on the prescribed drugs and not incorporate any effective alternative treatments into their treatment regimen. For this reason and the difference in the lifestyles of COPD patients, these predictions are not realistic or accurate much of the time. Much of it depends on whether you take an active role in your recovery or sit passively on the sidelines.

The medical industry uses the following statistical data as a general rule:

• More than 80% of people with mild COPD are alive after four years.

• 60% to 70% of people with moderate COPD are alive after four years.

• Among people with severe COPD (FEV1< 35% normal), about 50% are alive after four years.

• People with the worst possible COPD symptoms including the inability to walk through the house without getting winded along with severe weight loss, have the shortest COPD life expectancy. This is the stage my mother was in when we started the alternative treatments that ultimately saved her life.

According to WebMD,
“Those with stage 1 or 2 COPD lose at most a few years of life expectancy at age 65 compared with persons with no lung disease, in addition to any years lost due to smoking. But current smokers with stage 3 or 4 COPD lose about six years of life expectancy, in addition to the almost four years lost due to smoking.”

COPD Life Expectancy

Remember that COPD life expectancy varies widely, even between people with the same GOLD System scores (from their Spirometry or pulmonary function tests) and BODE index scores. Even with the most severe emphysema, the odds of surviving one year are higher than 90%. Your primary doctor or Pulmonary Specialist (lung doctor) can provide more detailed information.

By far, the most important determinant of emphysema prognosis and emphysema life expectancy is whether someone continues smoking. Quitting smoking is the single most important treatment that will improve emphysema life expectancy. Check out the Alternative Treatments page for information on increasing life expectancy and even reversing COPD completely.

Your Doctor Will Take Notice

Once you get used to calculating your own score in both the BODE Index and the GOLD System, you will be on a level playing field when talking to your doctor about what COPD stage you are in.

Trust me, they will take notice! The vast majority of their other patients do not know any of this information and can be easily swayed. You, on the other hand, are going in with the information and understanding of what is actually occurring with your COPD and how you calculate what COPD stage you are in.

Following is an article detailing the study on COPD Life Expectancy

"Life expectancy and years of life lost in chronic obstructive pulmonary disease: Findings from the NHANES III Follow-up Study"

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