2000 OPEN FORUM Abstracts
CLINICAL UTILITY FOR MEASURES OF BREATHLESSNESS
Deborah L. Cullen, EdD, RRT, FAARC, Respiratory Therapy Program, School of Allied Health Sciences, Indiana University School of Medicine, Indianapolis, IN
Background: Measures of dyspnea have been debated in the medical community as to their clinical utilization. Although breathlessness may be evaluated through multiple instruments, the most effective measure for a specific patient population or for measuring treatment effectiveness remains uncertain. Understanding primary and corollary validation work for these instruments may provide a key to appropriate clinical application. The purpose of this study was to evaluate the validity, reliability and responsiveness for measures of breathlessness. Methods: Scientific studies describing the original patient population and methods related to validity, reliability and responsiveness were chosen for analysis. The dyspnea measures analyzed included the Borg Scale, Visual Analogue Scale (VAS), Oxygen Cost Diagram (OCD), Medical Research Council Breathlessness Scale MRC), Baseline/Transition Dyspnea Index (BDI/TDI), Chronic Respiratory Questionnaire (CRQ/dyspnea scale), St George's Respiratory Questionnaire (SGRQ/activity domain). Content analysis for six constructs was carried out from the data presented in each study. All data was sorted by commonalities resulting in rating for clinical utility among the various measures of breathlessness. Results: Measures of dyspnea varied as to evidence of generalizability to various patient populations (COPD, asthma, lung transplant), concurrent and construct validity, internal consistency, inter-observer reliability and responsiveness. The Borg, VAS, OCD, MRC were more appropriate for dyspnea related to exercise, ADL's, and benchmarks. The BDI/TDI, SGRC, CRQ were clinically applicable to dyspnea related to outcomes, responsiveness and clinical trials. Conclusion: Since instrument construction and validation may limit the effectiveness for measuring clinical change (intra-patient sensitivity) as well as comparison among patients (inter-patient sensitivity), instrument appropriateness should be a primary consideration for selection.