Topical corticosteroids for chronic rhinosinusitis with nasal polyposis: GRADE systematic review and network meta-analysis

Background: Chronic rhinosinusitis with nasal polyposis (CRSwNP) is associated with a significant disease burden. The optimal use of and administration route for intranasal corticosteroids (INCS) when managing CRSwNP are unclear. Objective: We systematically synthesized the evidence addressing INCS for CRSwNP. Methods: We searched studies archived in Medline, Embase, and Central from database inception until September 1, 2021, for randomized controlled trials comparing INCS using any delivery method to placebo or other INCS administration types. Paired reviewers screened records, abstracted data, and rated risk of bias (CLARITY revision of Cochrane Risk of Bias version 1 tool) independently and in duplicate. We synthesized the evidence for each outcome using random effects network meta-analyses. We critically appraised the evidence following the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) approach. Results: We analyzed 61 randomized controlled trials (7176 participants, 8 interventions). Sinusitis-related quality of life might improve with INCS rinse (mean difference [MD] −6.83, 95% confidence interval [CI] −11.94 to −1.71) and exhalation delivery system (EDS) (MD −7.86, 95% CI −14.64 to −1.08) compared to placebo (both low certainty evidence). Nasal obstruction symptoms are likely improved when receiving INCS via stent/dressing (MD −0.31, 95% CI −0.54 to −0.08), spray (MD −0.51, 95% CI −0.61 to −0.41), and EDS (MD −0.35, 95% CI −0.51 to −0.18) (all moderate to high certainty) compared to placebo. We found no important differences in adverse effects among interventions (moderate certainty for INCS spray, very low to low certainty for others). Conclusions: Multiple delivery forms of INCS are viable therapeutic options for CRSwNP, resulting in improvement of patient-important outcomes. INCS via stent, spray, and EDS appear to be beneficial across the widest range of considered outcomes.