Objective evidence is coded where the diagnosis is supported by current use of chronic lung disease pharmacological therapy (e.g. inhalers, theophylline, aminophylline, or steroids), or a forced expiratory volume in 1 second (FEV1) less than 80% predicted FEV1/forced vital capacity (FVC) less than 0.7 (post bronchodilator). Respiratory failure partial pressure of oxygen (PaO2) less than 60 mmHg (8kPa), or partial pressure of carbon dioxide (PaCO2) greater than 50 mmHg (6.7 kPa).
For each Person—concurrent clinical condition (acute coronary syndrome), code NN, the data elements Person—clinical evidence status(chronic lung disease), code N; Person—clinical evidence status(heart failure), code N; Person—clinical evidence status(stroke), code N; Person—clinical evidence status(peripheral arterial disease), code N; Person—clinical evidence status(sleep apnoea syndrome), code N must also be recorded.
The diagnosis rests on the airflow limitation, which is not fully reversible. Consider treating as asthma if airflow limitation is substantially reversible. (The Thoracic Society of Australia & New Zealand and the Australian Lung Foundation, Chronic Obstructive Pulmonary Disease (COPD) Australian & New Zealand Management Guidelines and the COPD Handbook. Version 1, November 2002.)