Primary outcome

Balance assessment. The choice of the balance tests depends on the objective of the assessment. Searching the literature, we found that the most commonly used tests are: the Berg Balance Scale (BBS), Timed Up and Go (TUG), and single-leg stance test (SLS) [35]. Often Activities Balance Confidence scale (ABC) is considered as a part of the clinical balance assessment.

Berg Balance Scale (BBS). The BBS is the most widely accepted and psychometrically robust clinical measure of balance for COPD patients [36]. It measures 14 different tasks based on activities such as transfers, reaching, flipping, and single-leg; each attitude was scored on a scale from 0 (unable/unsafe) to 4 (independent/effective/safe), with higher total scores indicating better balance control and a total score out of 56. The threshold was 46, and scores <46 identifies a risk of falling [37].