Table 1 Trial design

The MACRO trial [11]

Design: Three-arm parallel-group RCT.

Setting: Outpatient Ear, Nose and Throat (ENT) departments in tertiary care.

Participants: Adults with uncomplicated Chronic Rhinosinusitis with or without nasal polyps.

Interventions: Participants randomised to receive: (1) intranasal medication plus ESS, (2) intranasal medication plus clarithromycin (250 mg) or (3) intranasal medication plus a placebo. The placebo consisted of an inert substance encapsulated in a red capsule. In order to achieve double blinding, the antibiotic clarithromycin was encapsulated in identical red capsules and all packaging was identical.

Intranasal medication (current standard medical care) is defined as a spray or drops of intranasal corticosteroids and saline irrigations.

Primary outcome measure: change at 6 months in the the SNOT-22 questionnaire, which assesses disease-specific health-related quality of life.

Study sample size: pilot phase n = 3. Main trial n = 600.