Types of overdiagnosis and misdiagnosis
| 1 | Physician COPD diagnosis despite normal spirometry |
| The physician did not use spirometry to establish a diagnosis of COPD (and a normal spirometry was later found in the study) | |
| The physician “ignored” a normal spirometry result | |
| 2 | Discordant results for COPD diagnosis based on different spirometry-based definitions for airflow obstruction (e.g. post-bronchodilator FEV1/FVC <0.7 or FEV1/FVC <LLN) |
| 3 | COPD diagnosis based on pre-bronchodilator spirometry results |
| 4 | Comorbidities (e.g. heart failure or asthma) that affect spirometry and have clinical features which overlap with COPD |
| 5 | Normalisation of abnormal (post-bronchodilator) spirometry at follow-up |