This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record.
1. Trial at a Glance
| Feature | BAT |
|---|---|
| Condition | Bronchiectasis; Inflammation |
| Design | Randomized, parallel, quadruple masked |
| Primary purpose | Treatment |
| Interventions | Azithromycin and placebo |
| Sponsor | W.G.Boersma |
| Status | Completed |
2. Clinical Question
Population
Patients with bronchiectasis.
Intervention
Prolonged azithromycin treatment.
Comparator
Placebo.
Primary question
Does prolonged antibiotic treatment with AZM reduce bacterial exacerbations and improve lung function parameters?
3. Trial Design
The BAT study was a phase 3 randomized, parallel-group, quadruple-masked treatment trial with 72 participants and two treatment arms. The registry lists azithromycin and placebo as the study interventions.
| Design element | Description |
|---|---|
| Allocation | Randomized |
| Masking | Quadruple |
| Model | Parallel |
| Enrollment | 72 |
| Start date | 2008-04 |
| Primary completion date | 2009-12 |
4. Endpoints
| Endpoint | Time frame |
|---|---|
| Does prolonged antibiotic treatment with AZM reduce the number of bacterial exacerbations in patients with bronchiectasis? | 1 year |
| Does treatment with AZM increase lung function parameters (Δ FEV1, Δ FVC )? | 1 year |
5. Planned Analysis
The ClinicalTrials.gov record identifies the primary questions and measurement timeframe but does not report posted statistical analyses or numerical outcome results.
For an endpoint evaluating the number of bacterial exacerbations, an analysis would typically compare event frequency between randomized groups using a method appropriate for count outcomes, such as a rate-based model. For lung function changes such as Δ FEV1 and Δ FVC, statistical analysis would typically compare changes from baseline between groups using methods appropriate for continuous outcomes.
6. Statistical Methodology
Randomization
Randomization creates comparable treatment groups on average and provides the basis for estimating treatment effects without relying on measured baseline differences.
Masked treatment comparison
Quadruple masking reduces the potential for expectations about treatment assignment to influence treatment delivery, assessment, or interpretation.
Count outcomes and lung function measures
The trial contains two different endpoint types: bacterial exacerbation frequency and continuous lung function parameters. These require different statistical frameworks because they answer different questions.
7. Statistical Methods Explained
Why does randomization matter?
Randomization is intended to balance known and unknown factors between groups, allowing differences after treatment assignment to be attributed to the randomized comparison.
Why analyze exacerbations differently from FEV1?
Exacerbations represent clinical events occurring over follow-up, while FEV1 and FVC are numerical measurements of lung function. Event counts and continuous measurements generally require different statistical approaches.
What does a one-year endpoint mean?
A one-year timeframe defines when outcomes are evaluated. It does not by itself describe the size or direction of any treatment effect.
Why is masking important?
Masking helps limit bias when participants, investigators, or assessors may otherwise be influenced by knowledge of treatment assignment.
8. Limitations
- The registry does not report posted statistical analyses or numerical results for the primary endpoints.
- The available record does not provide effect estimates, confidence intervals, or p-values.
- Without posted analyses, the magnitude and precision of treatment differences cannot be evaluated from the registry information alone.
- The registry does not report subgroup analyses, safety results by arm, or additional statistical design details.
9. Why This Trial Matters Statistically
| Concept | Application |
|---|---|
| Randomized trial design | Comparison of azithromycin versus placebo |
| Masking | Quadruple-masked treatment evaluation |
| Endpoint selection | Clinical exacerbations and lung function measures |
| Different outcome types | Event-based and continuous outcomes require different analyses |
10. Sources
- ClinicalTrials.gov record: NCT00415350
- PubMed: 34974413
- PubMed: 23532241