Chronic Obstructive Pulmonary Disease (COPD): Classification

Early COPD is present when:

  • Age <50 years
  • EV1/FVC < 0.70, FEV1 > 50% of target value
    • Low COPD activity = no symptoms, no exacerbations.
    • High COPD activity = symptoms and > 2 exacerbations/year.

Assess severity of COPD by lung function impairment (GOLD criteria; Global Initiative for Chronic Obstructive Lung Disease):

Patients with FEV1/FVC<0.70 (based on FEF1 after administration of a bronchodilator/”asthma spray”).
Severity Risk group FEV1
Severity I (GOLD 1) Mild FEV1 ≥ 0.80% of the target value
Severity II (GOLD 2) Moderate 50 % ≤ FEV1 < 80 % of the target value
Severity III (GOLD 3) Severe 30 % ≤ FEV1< 50 % of the target value
Severity IV (GOLD 4) very severe FEV1 <30% of the set point

Legend

  • FEV1 = forced expiratory one-second volume.
  • FVC=forced expiratory vital capacity (= lung volume that can be exhaled at maximum rate (forced) after maximum inspiration (inhalation)).

For everyday practice, the BODE index has become widely accepted:

Parameter 0 points 1 point 2 points 3 points
FEV 1 (%) ≥ 65 64-50 49-36 ≤ 35
Walking distance in 6 min (in m) ≥ 350 349-250 249-150 ≤ 149
mMRC Dyspnea Scale 0-1 2 3 4
Body mass index (BMI; kg/m²) > 21 ≤ 21

Legend

  • FEV1 = forced expiratory one-second volume.
  • MMRC Dyspnea Scale =scale used to classify dyspnea (see below).

The BODE index is used for prognosis and follow-up of COPD.

Evaluation:

  • Correlation with all-cause mortality: the higher the score, the higher the mortality (mortality).

In the revised guidelines, exacerbation history plays a greater role, along with GOLD classification and symptomatology:

Risk Classificationby GOLD Number of exacerbations in the last 12 months
High risk C D 43
  • ≥ 2 or
  • ≥ 1, which led to hospital admission
Low risk A B 21
  • 0 or 1 that did not result in hospital admission.
less symptoms more symptoms
mMRC 0-1CAT < 10 mMRC ≥ 2CAT ≥ 10

CAT = COPD Assessment Test

mMRC = (Modified British Medical Research Council): classification of dyspnea (shortness of breath) in COPD patients according to mMRC:

mMRC grade Description
0 Dyspnea (shortness of breath) during heavy exertion
I Dyspnea during rapid walking or during gentle ascents
II Walking slower than peers due to dyspnea
III Dyspnea at walking distance around 100 m
IV Dyspnea during dressing/dressing

The higher the grade, the more severe the dyspnea.