| Methods |
Single centre randomised double blind cross‐over study. |
| Participants |
CF patients, aged 6‐20 years (mean, 11.7 years). |
| Interventions |
Azithromycin, 250 mg (or 500 if weight >40 kg) 3 times a week or placebo for 4 months, then following 2‐month washout period cross‐over to other arm for 4 months. |
| Outcomes |
Primary: comparative change in FEV1. Also QoL and nutritional parameters. Adverse events. |
| Notes |
Northern Ireland study. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Computer‐generated random numbers in pharmacy. |
| Allocation concealment (selection bias) |
High risk |
Placebo were coloured red and the intervention brown (known by pharmacy but not investigators, CF team or participants, but resulted in speculation). |
| Blinding (performance bias and detection bias)
All outcomes |
High risk |
See above, a concern. |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
21 randomised and completed first arm. 4 dropped out for second arm and not included in comparative analysis. |
| Selective reporting (reporting bias) |
Low risk |
All outcomes measured were reported. |
| Other bias |
Low risk |
None identified. |
