Determinants of the modified incremental step test in patients with bronchiectasis

This study was conducted to investigate the determinants of the Modified Incremental Step Test (MAHBT) in patients with bronchiectasis. 46 clinically stable adult bronchiectasis patients participated in the study. Demographic and clinical information of the participants were recorded by the researcher. Dyspnea perception was determined by the Medical Research Council Scale (MRC) and the severity of the disease with the Bronchiectasis Severity Index (BSI). Functional exercise capacity; Modified Incremental Step Test and Incremental Shuttle Walk Test (AHMYT) were tested. 8 m Walking Speed (G-Walk accelerometer), Quadriceps Muscle Strength (hand-held dynamometer) and Physical Activity Level (Yamax CW-700 pedometer) were evaluated. Fatigue level was assessed Fatigue Severity Scale (FSS). Leichester Cough Questionnaire (LCQ) and St. George's Respiratory Questionnaire (SGRQ) were used to determine the quality of life. As a result of the study, MAHBT number of steps was found to be correlated with BSI score, quadriceps muscle strength, daily step count, walking speed, fatigue, SGRQ total score and LCQ total score (p <0.05). There was no correlation between the MAHBT number of steps and dyspnea perception and (p> 0.05). Multiple linear regression analysis indicated that BSI score, quadriceps muscle strength, number of daily steps and SGRQ total score were independent factors explaining 61.9% of the MAHBT number of steps in patient with bronchiectasis (p <0.05). The regression equation was found "MAHBT step number = 86.932 - (6.028 x BSI score) + (8.447 x quadriceps muscle strength) + (0.006 x pedometer daily step number)- (1.75 x SGRQ total score)". In conclusion, disease severity, quadriceps muscle strength, daily step count and SGRQ total score are determinants of MAHBT in patients with clinically stable bronchiectasis. The results of the study guide patients with bronchiectasis to plan their pulmonary rehabilitation programs. Keywords: bronchiectasis, exercise, step test, physical activity, quality of life