This BODE index for COPD calculator diagnoses and predicts the survival outcome in patients with chronic obstructive pulmonary disease. Below the form you can read more about the variables used in the score and its interpretation.
How does this BODE index for COPD calculator work?
This health tool is based on the multidimensional scoring system, the Body mass index, Obstruction, Dyspnea and Exercise Index and helps in the diagnosis of chronic obstructive pulmonary disease and in predicting the long term outcome of patients suffering from it.
This BODE index for COPD calculator takes into account the major factors of influence and the system nature of the disease and comprises of the following:
■ Body mass index - BMI result, as a variable dependant on the height and weight of the patient.
■ Obstruction of airflow - represented by the FEV1 variable (the forced expiratory volume in one second). It concerns the biggest amount of air that can breathed out during the first second of expiration.
- Stage 1 - mild: 64% or above (other symptoms are required to put a diagnosis).
- Stage 2 - moderate: 50 - 64%.
- Stage 3 - severe: 35 - 49%.
- Stage 4 - very severe: below 35%.
■ Dyspnea - based on the modified MRC dyspnea scale.
- Grade 0: Breathless only with strenuous exercise.
- Grade 1: Short of breath when hurrying on the level or walking up a slight hill.
- Grade 2: Slower than most people of the same age on the level because of breathlessness or have to stop for breath when walking at my own pace on the level.
- Grade 3: Stop for breath after walking about 100 meters or after a few minutes at my own pace on the level.
- Grade 4: Too breathless to leave the house or I am breathless when dressing.
■ Exercise capacity - the test of the distance walked in six minutes.
The BODE index is said to surpass even the results of spirometry testing (with the well known FEV1) in terms of outcome prediction and the progress monitoring of COPD. As this is amongst the most common causes of death after heart disease, stroke and cancer and a frequent comorbidity, significant progress has been done in trying to predict its outcomes.
Like other lung disease related indices, such as the CURB 65, it accounts for pulmonary and non pulmonary factors all together to predict survival. Other observations include major weight loss, anemia and relevant reductions in lean body mass.
BODE score interpretation
Once the assessment is performed, each of the choices is awarded the corresponding number of points which in turn are summed to reveal the final score. Results range from 0 to 10 and vary according to the criteria choices. The following table presents the points awarded to each of the criteria choices.
|FEV1||≥65||50 - 64||36 - 49||≤35|
|dyspnea scale||0 - 1||2||3||4|
|6 min walk (m)||≥350||250 - 349||150 - 249||≤149|
The results are based on an original study of 207 patients with COPD and on subsequent validations. The hazard ratio for all cause mortality is set at 1.34 for every one increment increase in the index. The hazard ratio for respiratory disease related mortality is set at 1.62 for every increase in one point in the BODE index.
|BODE index score||52 month mortality rate|
|0 – 2 points||20%|
|3, 4 points||60%|
|5, 6 points||70%|
|7 – 10 points||80%|
The above index is also used in the differential diagnosis with other diseases such as pneumoconiosis, bronchiectasis, allergic fibrosis, bronchopulmonary dysplasia or congestive heart failure (CHF).
The GOLD classification
The Global Initiative on Obstructive Lung Disease classification of COPD severity:
■ Stage 0: no diagnosis but at risk with chronic cough and sputum production present but with normal spirometry.
■ Stage I: mild COPD characterized by mild airflow limitation (FEV1/FVC less than 70% but FEV1 80% or more than predicted).
■ Stage II: moderate COPD, indicated by worsening airflow limitation (FEV1 50 - 79% predicted) and usually progression of symptoms, with shortness of breath on exertion.
■ Stage III: severe COPD characterized by further worsening of airflow limitation (FEV1 30 - 50% predicted), increased shortness of breath, and repeated exacerbations.
■ Stage IV: very severe COPD with severe airflow limitation (FEV1 less than 30% predicted) or the presence of chronic respiratory failure.
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