Factors of success of low-dose macrolides in chronic sinusitis: Systematic review and meta-analysis

Objective To assess the prognostic factors that predict favorable outcomes of low-dose macrolides (LDMs) in treating chronic rhinosinusitis (CRS). Methods Randomized controlled trials studying the effects of LDMs in treating CRS were included. Data were pooled for meta-analysis. Primary outcome was Sino-Nasal Outcome Test (SNOT). Six prognostic factors: CRS subtypes, serum immunoglobulin (Ig)E level, membered lactone ring of macrolides, concurrent endoscopic sinus surgery (ESS), and dosage and duration of the LDMs were assessed by subgroup analyses. Results Ten studies (608 patients) met the inclusion criteria. LDMs and placebo were not different in SNOT improvement (standardized mean difference [SMD] = -0.23, 95% confidence interval [CI]: -0.69 to 0.24). Subgroup analyses showed that the effects favored LDMs in the patients with CRS without polyps (SMD = -0.64, 95% CI: -1.01 to -0.27) compared to CRS with polyps, and the patients receiving a half dose (SMD = -0.64, 95% CI: -1.01 to -0.27) compared to a very low dose. There was no difference in SNOT improvement between LDMs plus standard treatment compared to standard treatment (SMD = -0.52, 95% CI: -1.57 to 0.53). Subgroup analyses showed that the effects favored LDMs in the patients receiving LDMs for a duration of 24 weeks (SMD = -1.68, 95% CI: -2.40 to -0.95) compared to 8 and 12 weeks. There was no difference between the 14-membered and 15-membered ring LDMs. Assessment of concurrent ESS found mixed results. Serum IgE level could not be assessed. Conclusions LDMs provided favorable outcomes in patients with CRS without polyps. A half dose of macrolides should be given for a duration of 24 weeks. Level of Evidence 1a Laryngoscope, 129:1510-1519, 2019