Emphysema The outcome could be based on the ICD code for emphysema, on medical records, in-study diagnosis, or on self-report of physician diagnosis or history of the disease. Choice of outcome Where a study provided data for multiple acceptable definitions of an outcome, results were entered ...
Those who had made physician visits for traffic accidents (ICD-9 code: E800-E848) or acute gastroenteritis (ICD-9 code: 008.8; 009.1; 558.3; 558.9) the same year and who had never been diagnosed as having chronic bronchitis were considered potential study controls. Any case or control ...