Antiviral treatment of Bell's palsy based on baseline severity: A systematic review and meta-analysis.

PURPOSE: We conducted a systematic review with meta-analysis to evaluate efficacy of antiviral agents on complete recovery of Bell's palsy. METHODS: We searched CENTRAL, EMBASE, MEDLINE, International Pharmaceutical Abstracts, and sources of unpublished literature to November 1, 2014. Primary and secondary outcomes were complete and satisfactory recovery, respectively. To evaluate statistical heterogeneity, we performed subgroup analysis of baseline severity of Bell's palsy as well as between-study sensitivity analyses based on risk of allocation and detection bias. RESULTS: The 10 included randomized controlled trials (2419 patients; 807 with severe Bell's palsy at onset) had variable risk of bias, with nine trials having high risk of bias in at least one domain. Complete recovery was not statistically significantly greater with antivirals versus no antivirals in the random-effects meta-analysis of 6 trials (relative risk (RR) 1.06, 95% confidence interval (CI) 0.97-1.16; I2 = 65%). Conversely, random-effects meta-analysis of 9 trials showed a statistically significant difference in satisfactory recovery (RR 1.10, 95% CI 1.02-1.18; I2 = 63%). Response to antiviral agents did not differ visually or statistically between patients with severe symptoms at baseline and those with milder disease (test for interaction, p = 0.11). Sensitivity analyses did not show a clear effect of bias on outcomes. CONCLUSIONS: Antiviral agents are not efficacious in increasing the proportion of patients with Bell's palsy who achieved complete recovery, regardless of baseline symptom severity.