Primary outcome
Survival without physiologically defined moderate or severe chronic lung disease at 36 weeks’ postmenstrual age.
For researchers & clinicians
AZTEC scientific resources
Trial design, statistical methods, follow-up methodology, microbiology, antimicrobial resistance and peer-reviewed publications from the AZTEC programme.
Trial design
Multicentre, double-blind, randomised, placebo-controlled
The main AZTEC trial recruited 799 infants born before 30 weeks’ gestation. Three complete withdrawals left 796 participants in the final analysis. The intervention was a 10-day course of intravenous azithromycin compared with matched placebo.
Clinical outcomes
Neonatal morbidity, adverse events, respiratory outcomes and other clinically important endpoints.
Mechanistic studies
Respiratory inflammation, Ureaplasma, microbiome and antimicrobial-resistance analyses.
Core documents
Protocols and methods
Protocol
Main AZTEC protocol
Detailed rationale, eligibility, intervention, outcomes, sampling and trial procedures.
Statistical analysis plan
Clinical outcomes SAP
Pre-specified statistical methods for the principal clinical analyses.
Follow-up protocol
AZTEC-FU study protocol
Respiratory outcomes at 1 year and neurodevelopmental, growth, mortality and safety outcomes through 2 years’ corrected age.
Microbiology & AMR
A major scientific strand of AZTEC
The programme was designed not only to test clinical efficacy but also to understand the biological and antimicrobial consequences of neonatal azithromycin exposure.
Baseline resistance
The gut microbiota of preterm infants already contained substantial macrolide resistance before or early in trial exposure, an important context for interpreting antibiotic effects.
Respiratory resistance
Subsequent analyses examine macrolide resistance within the respiratory tract during treatment and after exposure.
Trial archive
Operational study resources
The original AZTEC website contains study guidance, data-collection forms, treatment preparation information, sampling and shipment guidance, training materials and historical newsletters. These remain useful as an archive of trial delivery.