Acute exacerbations of bronchiectasis are associated with variable outcomes depending on patient factors. Comorbidities such as COPD, diabetes, and cardiovascular disease, as well as disease severity scores, significantly influence hospitalization rates, length of stay, need for intensive care, and mortality. Understanding these associations helps in risk stratification, guiding management, and improving prognosis in affected patients.

Bronchiectasis is a chronic respiratory condition characterized by permanent and abnormal dilatation of the bronchi, often associated with recurrent infections, impaired mucociliary clearance, and progressive lung damage. Acute exacerbations represent a major clinical problem, contributing to significant morbidity, reduced quality of life, and increased healthcare burden.

The clinical outcomes of patients experiencing acute exacerbations of bronchiectasis are not uniform, and multiple factors influence their prognosis. Among these, comorbidities and disease severity play crucial roles. Comorbidities such as chronic obstructive pulmonary disease (COPD), asthma, cardiovascular diseases, diabetes mellitus, and chronic renal impairment can increase susceptibility to exacerbations and worsen their clinical course. The presence of these comorbid conditions is often linked to prolonged hospital stays, higher rates of intensive care admission, frequent readmissions, and increased mortality.

Similarly, the severity of underlying bronchiectasis, often assessed through validated scoring systems (e.g., Bronchiectasis Severity Index [BSI], FACED score), is strongly correlated with outcomes during exacerbations. Patients with more severe disease tend to experience more frequent and severe exacerbations, impaired lung function, greater need for intravenous antibiotics, and higher risk of complications.

Therefore, assessing both comorbidity burden and disease severity is critical in predicting outcomes, guiding clinical decision-making, and tailoring individualized management strategies for patients presenting with acute exacerbations of bronchiectasis. A comprehensive understanding of these relationships will aid in early risk stratification, optimization of treatment, and potentially reduction of adverse outcomes in this vulnerable patient population.

Inclusion Criteria:

• Adults (≥18 years) admitted with a diagnosis of "Bronchiectasis with acute exacerbation". The bronchiectasis exacerbation is diagnosed based on deterioration in three or more of the following main symptoms for 48h at least: cough, sputum volume or sputum consistency, purulent sputum, breathlessness or exercise tolerance, fatigue or malaise, hemoptysis, and the requirement of a change in the bronchiectasis treatment as determined by a clinician.

Exclusion Criteria:

• Patients younger than 18 years of age. Patients who refuse participation or whose medical records lack informed consent (if applicable).

The study population will include adult patients (≥18 years) diagnosed with bronchiectasis who are admitted to the hospital with acute exacerbations. Patients will be recruited from the Department of Chest Diseases at Sohag University Hospital (or your hospital name). All eligible patients during the study period will be included consecutively. Data regarding demographic characteristics, comorbidities, disease severity scores (BSI or FACED), and clinical outcomes will be collected and analyzed.

Individual participant data (IPD) will not be shared. The collected data will be used only for the current study purposes and will remain confidential according to institutional regulations.