Dyspnea scales in the assessment of illiterate patients with chronic obstructive pulmonary disease

Background: Multiple physiological, psychological, social and environmental factors may affect the perception of dyspnea. Although different scales ha ve been used to record the severity of dyspnea in subjects with chronic obs tructive pulmonary disease (COPD), none has reported evaluating the propert ies of such tools in illiterate patients. The objective of this study was t o evaluate the reliability and features of concurrent validity of 4 dyspnea scales in illiterate (IL) subjects with COPD. Methods: One hundred COPD pa tients submitted to spirometry and were asked to score their breathlessness using a visual analogue scale (VAS), a numerical rating scale (NRS), the B org scale (BS), and the basal dyspnea index (BDI). Each scale was presented to the patients before and after they had performed spirometry and measure ment of residual volume. The obtained scores were analyzed according to the literacy status of the patients. Results: Thirty-three patients were class ified as IL and 67 as literate (L). Both groups showed similar respiratory impairment and median scores of dyspnea (VAS, L = 45.0, IL = 49.0; NRS, L = 5.0, IL = 5.0; ss, L = 3.0, IL = 3.0; BDI, L = 5.0, IL = 4.0). No signific ant differences were found between the dyspnea scores obtained before and a fter spirometry for all scales in both groups. The degree of correlation be tween forced expiratory volume in 1 second (FEV1) and usual dyspnea evaluat ed by BDI did not show a statistical difference between the two groups (L, r = 0.37; IL, r = 0.51). Conclusion: The employed dyspnea scales showed com parable reliability in both L and IL COPD subjects.