A symptom-based measure of the severity of chronic lung disease: results from the Veterans Health Study.

STUDY
OBJECTIVES: We developed a symptom-based measure of severity for chronic lung disease (CLD) that can be readily administered in ambulatory care settings and be used to supplement general health-related quality of life (HRQoL) assessments and pathophysiologic indicators in research and clinical care.
DESIGN: Cross-sectional data from the Veterans Health Study, an observational study of health outcomes in patients receiving Veterans Affairs (VA) ambulatory care.
SETTING: Four VA outpatient clinics. STUDY
SUBJECTS: Two hundred ninety-two participants with CLD were identified on the basis of patient report of having a physician's diagnosis of chronic bronchitis, emphysema, or asthma and either using inhaled medications or having a productive cough on most days for 3 months. MEASUREMENTS AND
RESULTS: Participants were scheduled for an in-person interview in which they completed a CLD questionnaire and measurements of peak expiratory flow rate (PEFR). They were also mailed an HRQoL questionnaire, the Short Form Health Survey (SF-36). The CLD questionnaire included six symptom items chosen by an expert panel (two items each for dyspnea, wheezing, and productive cough). The combination of these items yielded a CLD severity index that correlated significantly with all eight scales of the SF-36 (range of r, -0.19 to -0.37; p<0.01). In contrast, PEFR had statistically significant correlations only with two SF-36 scales: physical functioning and bodily pain.
CONCLUSIONS: The CLD severity index is a reliable and valid patient-administered instrument that may be used to evaluate the effects of CLD on general HRQoL and predict future health services utilization.