RESUMEN
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.