CHANGES IN DYSPNEA, HEALTH-STATUS, AND LUNG-FUNCTION IN CHRONIC AIRWAY DISEASE

The purpose of this study was to examine longitudinal changes in clini cal parameters in patients with chronic obstructive pulmonary disease (COPD). We postulated that progressive dyspnea and decline in lung fun ction over time would influence or impact patient's health status. Cli nical ratings of dyspnea, general health status, and physiologic lung function were measured every 6 mo over a 2-yr period in an original gr oup of 110 male patients with stable but symptomatic COPD and no signi ficant comorbidity. At enrollment, age was 67 +/- 8 yr(mean +/- SD), f orced expiratory volume in one second (FEV(1)) was 1.28 +/- 0.59 l (44 +/- 17% of predicted), and forced vital capacity (FVC) was 2.84 +/- 0 .84 l (68 +/- 18% of predicted). A total of 34 patients ''dropped out' ' because of death (n = 20), relocation (n = 7), and other reasons (n = 7). Dyspnea was measured using the transition dyspnea index (TDI), w hich represented changes from the baseline state; general health statu s was measured using the Medical Outcomes Study (MOS) 20-item short-fo rm survey; physiologic lung function was assessed by spirometry (FVC a nd FEV(1)) and inspiratory muscle strength (P-lmax) Statistical analys es were performed using all available data for each patient, including results until the time at which patients died or were lost to follow- up. Repeated measures analysis of covariance showed there were signifi cant decreases in the TDI focal score (-0.7 +/- 2.9; p = 0.04), P-lmax (from 59.0 +/- 25.0 to 55.6 +/- 26.2 cm H2O; p < 0.001), and physical functioning score of the MOS survey (from 32.7 +/- 26.4 to 25.7 +/- 2 7.2; p < 0.001) over the 2-yr period. Although changes were also noted for FVC (p < 0.02) and FEV(1) (p < 0.02), these measures did not incr ease or decrease consistently over time. The five other health compone nts of the MOS showed no significant change over time. The changes in dyspnea were significantly related to changes in lung function. Regres sion analysis revealed that the TDI focal score was a significant pred ictor for all components of general health; status whereas FEV(1) was a significant predictor of five of the six components of health. We co nclude that dyspnea, P-lmax, and physical functioning decline over 2 y r in a cohort of patients with symptomatic COPD Both dyspnea ratings a nd lung function, particularly FEV(1), were significant predictors of various components; of general health status. It is possible that phys ical functioning is the initial health component to. decline in patien ts with COPD, whereas a longer time period may be required to demonstr ate changes, in other components. Alternatively, patients with COPD ma y adapt to deterioration in dyspnea and physiologic function by adjust ing their lifestyle to maintain role and social functioning, mental he alth, and health: perceptions and minimize pain.