What is the robustness of randomized controlled trials supporting rhinosinusitis guidelines?

Purpose: To determine the robustness of randomized controlled trials (RCTs) supporting the current rhinosinusitis guideline; International Consensus Statement on Allergy and Rhinology: rhinosinusitis (ICAR-RS). Materials & methods: RCTs referenced by ICAR-RS with primary dichotomous outcomes were analyzed. The Fragility Index (FI) was calculated for trials with statistically significant findings. Trial characteristics, the FI, and FI minus number lost to follow-up (LTF) were assessed for associations. Results: A total of 317 RCTs were identified, with 38 trials possessing a primary dichotomous outcome. Thirty-one percent evaluated surgical interventions and 24 % were industry-sponsored. The mean sample size was 116 with 9 patients, on average, LTF. Sixty-three percent were eligible for FI calculation and had a median FI of 2.5 (IQR 1, 4.25). Sixty-seven percent of trials had an FI ≤ 3, indicating low robustness. No difference in FI was observed between trials with and without industry support (p = 0.577). The FI was less than or equal to the number of patients LTF in 33 % of trials (n = 8). Higher FI was strongly correlated with higher sample size, total number of events, p-value, and grade of recommendation (p < 0.001). After adjusting for covariates, higher sample size and total number of events were associated with higher FI. Conclusion: The RCTs used to support the ICAR-RS have an overall low robustness and future rhinosinusitis trials should report FI measures to provide improved context of their results.