BASE: Bronchiectasis Severity and Exacerbation Risk Study
Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age18+
SponsorAssiut University
About this trial
Non-cystic fibrosis bronchiectasis (NCFB) is a chronic airway disease characterized by permanent bronchial dilatation, impaired mucus clearance, recurrent infection, airway inflammation, and repeated exacerbations. Existing bronchiectasis severity tools are clinically useful, but many depend on prior exacerbation history, hospitalization history, subjective symptom assessment, or culture-based microbiological classification.
This prospective observational cohort study aims to develop and validate the Bronchiectasis Assessment of Severity and Exacerbations (BASE) framework. BASE is designed to classify current bronchiectasis severity and predict 12-month exacerbation risk using objective baseline functional, radiological, oxygenation, and inflammatory variables. Detailed methodological specifications, including variable definitions, scoring architecture, endpoint hierarchy, development-validation governance, and analytical integrity rules, are archived in a restricted-access Zenodo record: https://doi.org/10.5281/zenodo.20143505
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Participants will receive routine clinical care, and no treatment or intervention will be assigned by the study protocol. Patients will be followed for 12 months to record bronchiectasis exacerbations, hospitalization, lung-function change, inflammatory marker change, and clinical outcomes. The Bronchiectasis Assessment of Severity and Exacerbations (BASE) framework includes two linked baseline models: the BASE Severity model (BASE-S) for current bronchiectasis severity classification and the BASE Prognostic model (BASE-P) for prediction of 12-month exacerbation risk. Both models will be derived in the development cohort and applied unchanged to the validation cohort.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Adult patients aged 18 years or older.
Diagnosis of non-cystic fibrosis bronchiectasis (NCFB) based on clinical assessment and high-resolution computed tomography (HRCT).
Clinically stable or routinely assessed patients with non-cystic fibrosis bronchiectasis (NCFB) eligible for baseline severity and risk assessment.
Patients attending outpatient clinic, inpatient ward, or respiratory follow-up services at Assiut University Hospitals during the study enrollment period.
Disqualifiers
Cystic fibrosis-related bronchiectasis.
Traction bronchiectasis due to advanced fibrotic interstitial lung disease as the dominant respiratory diagnosis.
Active pulmonary tuberculosis at enrollment.
Active nontuberculous mycobacterial pulmonary disease requiring specific treatment at enrollment.
Trial population
Adult patients with non-cystic fibrosis bronchiectasis (NCFB) attending outpatient clinics, inpatient wards, or respiratory follow-up services at Assiut University Hospitals during the study enrollment period will be prospectively screened for eligibility. Eligible participants will have clinically and radiologically confirmed non-cystic fibrosis bronchiectasis (NCFB) and will undergo baseline assessment using the Bronchiectasis Assessment of Severity and Exacerbations (BASE) framework, followed by 12-month follow-up for bronchiectasis exacerbations, hospitalization, functional change, inflammatory marker change, and clinical outcomes. Participants will receive routine clinical care, and no treatment or intervention will be assigned by the study protocol.
Trial design
Design model
Cohort
Time perspective
Prospective
Treatments tested in this trial
Not listed
Trial groups
750 Participants
are grouped into 2 trial groupsGroup A: Development Cohort
Group B: Validation Cohort
Trial outcomes
Primary outcomes
1
Twelve-Month Bronchiectasis Exacerbation Risk Predicted by the BASE Prognostic Model (BASE-P)
Occurrence of at least one bronchiectasis exacerbation during 12-month follow-up, used as the primary clinical endpoint for development and validation of the BASE Prognostic model (BASE-P). BASE-P is the 12-month risk-prediction component of the Bronchiectasis Assessment of Severity and Exacerbations (BASE) framework for adults with non-cystic fibrosis bronchiectasis (NCFB). Specific point ranges and risk categories have not yet been established and will be derived in the development cohort before locked validation. Higher BASE-P predicted risk values indicate higher expected exacerbation risk. Unit of Measure: Percentage of participants.
Time frame
Baseline to 12 months follow-up.Secondary outcomes
1
Current Bronchiectasis Severity Classification by the BASE Severity Model (BASE-S)
Baseline bronchiectasis severity classification using the BASE Severity model (BASE-S). BASE-S is the current severity-classification component of the Bronchiectasis Assessment of Severity and Exacerbations (BASE) framework for adults with non-cystic fibrosis bronchiectasis (NCFB). Specific severity point ranges and categories have not yet been established and will be derived in the development cohort before locked validation. Higher BASE-S severity categories indicate greater baseline bronchiectasis disease burden. Unit of Measure: Percentage of participants.
Time frame
Baseline Day 12
Time to First Bronchiectasis Exacerbation
Time from baseline assessment to the first recorded bronchiectasis exacerbation during follow-up. Participants without exacerbation will be censored at the last available follow-up date or at 12 months. Shorter time to first bronchiectasis exacerbation indicates earlier clinical deterioration and worse outcome. Unit of Measure: Days.
Time frame
Baseline to 12 months follow-up.3
Number of Bronchiectasis Exacerbations During Follow-Up
Total number of bronchiectasis exacerbations recorded for each participant during the 12-month follow-up period. Higher exacerbation count indicates greater disease instability and worse clinical outcome. Unit of Measure: Number of events.
Time frame
Baseline to 12 months follow-up.4
Severe Bronchiectasis Exacerbation Requiring Hospitalization
Occurrence of at least one bronchiectasis exacerbation requiring hospital admission during the 12-month follow-up period. Hospitalization-requiring exacerbation indicates more severe clinical deterioration and worse outcome. Unit of Measure: Percentage of participants.
Time frame
Baseline to 12 months follow-up.Other outcomes
1
Discrimination Performance of the Bronchiectasis Assessment of Severity and Exacerbations (BASE) Framework for Twelve-Month Bronchiectasis Exacerbation Risk
Evaluation of the discrimination performance of the Bronchiectasis Assessment of Severity and Exacerbations (BASE) framework for prediction of bronchiectasis exacerbation during 12-month follow-up using area under the receiver operating characteristic curve analysis. BASE is a novel baseline disease-signature model undergoing prospective derivation and validation in adults with non-cystic fibrosis bronchiectasis (NCFB). Specific bedside thresholds and operational risk categories have not yet been established and will be derived in the development cohort before locked validation. Unit of Measure: Area under the receiver operating characteristic curve (0-1 scale). Higher values indicate better discrimination performance.
Time frame
Baseline to 12 months follow-up.2
Calibration Performance of the Bronchiectasis Assessment of Severity and Exacerbations (BASE) Framework for Twelve-Month Bronchiectasis Exacerbation Risk
Assessment of calibration performance of the Bronchiectasis Assessment of Severity and Exacerbations (BASE) framework for prediction of bronchiectasis exacerbation during 12-month follow-up. Calibration performance will be assessed using calibration intercept and calibration slope where applicable. BASE is a novel baseline disease-signature model undergoing prospective derivation and validation in adults with non-cystic fibrosis bronchiectasis (NCFB). Unit of Measure: calibration slope values closer to 1 indicate better calibration performance.
Time frame
Baseline to 12 months follow-up.3
Clinical Utility of the Bronchiectasis Assessment of Severity and Exacerbations (BASE) Framework
Assessment of clinical utility of the Bronchiectasis Assessment of Severity and Exacerbations (BASE) framework using decision curve analysis and net benefit across clinically relevant threshold probabilities for prediction of bronchiectasis exacerbation during 12-month follow-up. BASE is a novel baseline disease-signature model undergoing prospective derivation and validation in adults with non-cystic fibrosis bronchiectasis (NCFB). Unit of Measure: Net benefit (unitless). Higher net benefit indicates greater clinical utility across the evaluated threshold probability range.
Time frame
Baseline to 12 months follow-up.4
Risk-Band Separation of the Bronchiectasis Assessment of Severity and Exacerbations (BASE) Framework
Assessment of separation between predefined Bronchiectasis Assessment of Severity and Exacerbations (BASE) risk categories for 12-month bronchiectasis exacerbation outcomes. BASE risk categories will be derived in the development cohort before locked validation. Outcome differences across risk categories will be assessed using exacerbation occurrence, exacerbation burden, and hospitalization-related outcomes where applicable. Unit of Measure: Percentage of participants. Higher observed event rates in higher BASE risk categories indicate better risk-band separation.
Time frame
Baseline to 12 months follow-up.Sponsors and contacts
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Source ClinicalTrials.gov