How accurate is the self-reported diagnosis of chronic bronchitis?

Background: Although it is defined as cough and sputum production for at least 3 months per year for at least 2 consecutive years, difficulties exist in the use of the term chronic bronchitis for clinical diagnosis. In particular, the relationship between diagnosis and symptoms has been difficult to ascertain. Study objectives: To determine, in a large epidemiologic study, the degree to which a new self-reported diagnosis of chronic bronchitis (NCBR) satisfies the symptom criteria for that diagnosis, and to determine the relationship between self-reported physician-confirmed diagnoses and symptom criteria. Methods: We analyzed data obtained from the Tucson Epidemiologic Study of Obstructive Lung Diseases. Using responses to standardized respiratory questionnaires administered to 4,034 subjects, those with NCBRs were selected and assessed as to whether they met symptom criteria for that diagnosis. Descriptive statistics pertaining to gender, age, and smoking status were obtained. Furthermore, we determined how often symptom criteria were met among a subset of subjects with physician-confirmed self-reported diagnoses. Results: Of 481 subjects with NCBRs, only 56 subjects (11.6%) met the required symptom criteria. Men compared with women and current smokers compared with ex-smokers or neversmokers were more likely to meet symptom criteria. Four hundred fifteen of 481 subjects with NCBRs had physician-confirmed self-reported diagnoses. Of these, only 52 subjects (12.5%) met symptom criteria. Within the subgroup of subjects who met symptom criteria, higher percentages were observed in the older age groups, but this was not statistically significant. Conclusion: Only a minority of subjects with NCBRs satisfy the symptom criteria of cough and sputum production for at least 3 months per year for at least 2 consecutive years. This relationship holds true even among those with physician-confirmed self-reported diagnoses.