The Risk of Falling in Patients with Chronic Obstructive Pulmonary Disease

Activities-Specific Balance Confidence (ABC) scale will be used for evaluating the confidence in maintaining the balance in activities daily living. It provides information on the level of concern about falls during16 community-based and home-based activities. Scale scores between 0 (unsafe) to 100 (completely safe) and the total score (0-1600) is divided by 16 to obtain an individual's ABC score, with higher scores indicating greater balance confidence. In patients with COPD, the ABC scale has demonstrated construct validity as well as criterion validity for falls. In addition, the participants will be also questioned concerning the occurrence of falls and the risk of falling during the activity in each item of the ABC scale.

Fall frequency will be investigated by asking patients to report any fall event in the last one month and the last 12-months. Participants will be asked: "Have you had any fall including a slip or trip in which you lost your balance and landed on the floor or ground or lower level?" Details about the circumstances of the fall and any resultant injury will be questioned.

Berg Balance Scale (BBS) will be used to assess the balance and determine the risk of falling in participants. It consists of 14-item evaluating a patient's ability to safely balance during a series of physical tasks. Scale scores between 0 (unable/unsafe) to 4 (independent/safe) and the total score ranges from 0 to 56, with higher scores indicating better balance control. The BBS has been demonstrated construct validity in patients with COPD.

London Chest Activity of Daily Living (LCADL) scale is used for assessing the level of dyspnea during daily activities. It is a 15-item scale comprised 4 domains: self-care (4 items), domestic (6 items), physical (2 items), and leisure (3 items). Each item scored between 0 (I wouldn't do it anyway) to 5 (I need help in doing this or someone to do it for me) and the total score ranges from 0 to 75, with higher scores indicating a more significant limitation in daily activities. The LCADL scale is a reliable, valid, and responsive instrument to assess limitations in performing daily activities in COPD patients. asked to rate each item in terms of risk of falling using a five-point scale, where 1=very low, 2=low, 3=moderate, 4=high, and 5=very high.

The COPD Assessment Test (CAT) will be used for evaluating the global impacts of COPD symptoms on overall health status. Each item scores between 0 to 5 and the total score ranges from 0 to 40, with higher scores indicating the more severe impact of COPD on health status.

The strength of quadriceps femoris of both sides will be measured with a hand-held dynamometer (kg.N-1) ''Nicholas Manual Muscle Tester" (model 01160, The Lafayette Instrument Company, Lafayette, Indiana). Each limb will assessed 3 times, with a recovery period of 30 seconds and the mean value will be calculated.

The Modified Medical Research Council Dyspnea (mMRC) scale will be used to determine how dyspnea limits the patients' daily activities performance. Itis a five-level rating scale consisting of just five items containing statements about the impact of dyspnea on the patients' daily activities performance and leading to a grade from 1 to 5. Higher scores indicate a greater impact of dyspnea on the patients' daily activities performance.

Six-Minute Walking Test (6MWT) is a reliable and valid test for evaluating functional capacity. Two 6MWTs will be performed according to the guidelines of the American Thoracic Society. The distance in meters covered over the 6 minutes of the test (6MWD) will be recorded.