Children with bronchiectasis and age-matched healthy controls will be evaluated with sit-to-stand test and six-minute walk test and utilization of STST in determining functional capacity will be investigated.

Bronchiectasis (BE) is a chronic condition which is characterized by the permanent abnormal widening of the bronchi as a result of repetitive airway infections and inflammation. Disabling cough and shortness of breath, excess mucus production, progressive airway obstruction and loss of skeletal muscle mass are the primary factors that impairs exercise tolerance in BE patients. Imaging modalities and pulmonary function test are insufficient to determine disease burden or the prognosis thus it is stated that exercise tolerance and quality of life should also be evaluated in these patients.

Exercise tolerance can be evaluated using cardiopulmonary exercise test by directly measuring oxygen consumption but the field tests such as six-minute walk test (6MWT), shuttle walk test or stair climbing tests also provides reliable data on exercise tolerance by measuring functional capacity. Among field tests, 6MWT is the most commonly used test for evaluating functional capacity in cardiopulmonary patients. Although 6MWT is easy to apply and does not require any special equipment, it still requires a 30-m long corridor and a total testing time of approx. 20 minutes considering the pre- and post-test resting periods which may impair its feasibility in some clinical settings.

Sit-to-stand test (STST) is firstly developed for older population to measure mobility related function and physical performance. Today, it is widely used in various populations including cardiopulmonary diseases such as cystic fibrosis, chronic obstructive pulmonary disease and heart failure. The investigator's aim in this study is to investigate whether STST is utilizable for evaluating functional capacity in children with BE.

Inclusion Criteria:

• Diagnosis of non-cystic fibrosis bronchiectasis

Exclusion Criteria:

• Hospitalization history in past month
• Diagnosis of other chronic pediatric diseases which may impair exercise tolerance such as cerebral palsy or neuromuscular disease
• Candidates for lung transplantation or history of lung transplantation

Children diagnosed with non-cystic fibrosis bronchiectasis and age matched healthy volunteers who do not have any diagnosed chronic diseases