Guidelines recommend the confirmation of a COPD diagnosis with spirometry. International Classification of Diseases, Ninth Revision, Clinical Modification, diagnostic codes are frequently used to identify patients with COPD for administrative purposes. However, coding the diagnosis of COPD does not require confirmation using spirometry. The purpose of this study was to determine how often the discharge diagnosis of COPD is supported by spirometric measurements in the Veterans Affairs (VA) health system.METHODS:
We reviewed records of patients hospitalized for COPD in a VA teaching hospital between 2005 and 2015. Individuals were counted once; rehospitalizations for COPD in the same time frame were excluded. Patient records were assessed for the presence of spirometric measurements and for spirometric evidence of COPD.RESULTS:
There were 1,278 discharges with the principal diagnosis of COPD and allied conditions in the time frame. A total of 826 discharged patients were included. Among them, 21% had no spirometric measurements, 12% were unable to perform the breathing maneuvers correctly, 56% had spirometric evidence of airways obstruction, and 11% had normal prebronchodilator or postbronchodilator FEV1/FVC measurements. Older patients were more likely to fail the spirometry test or have no documented spirometry. Younger patients were more likely to have the first spirometry conducted after their COPD hospitalizations.CONCLUSIONS:
Caution must be taken when using the discharge diagnosis database to measure health-care outcomes and determine resource management. Efforts are needed to assure that patients clinically suspected of having COPD are tested with spirometry to improve the accuracy of a COPD diagnosis.