| A | Specific COPD code only:Diagnostic COPD code or record of acute exacerbation of COPD in either primary care or secondary care data using previously validated Read or SNOMED-CT or International Classification of Diseases, Tenth Revision (ICD-10) codes11 (see Supplementary Tables S1 and S2 for additional codes used to identify COPD and COPD exacerbations using SNOMED-CT codes) |
| B | Specific COPD code and record of spirometry:Record of spirometry being performed at any time in a patient's medical history |
| C | Specific COPD code and medication prescribed within 4 weeks of a diagnostic code |
| D | Specific COPD code, presence of spirometry and medication prescribed within 4 weeks of a diagnostic code |
| E | Specific COPD code with post-bronchodilator spirometry confirmed obstruction(forced expiratory volume [FEV]1/forced vital capacity [FVC] <0.7) |
| F | Specific COPD code with post-bronchodilator spirometry confirmed obstructionFEV1/FVC < lower limit of normal (LLN) |