Objective: To estimate the natural history of acute rhinosinusitis and the impact of antimicrobial therapy on clinical outcomes.
Data sources: MEDLINE and Cochrane Trial Registry through February 2007 combined with manual review of retrieved article bibliographies.
Review methods: Systematic review and random-effects meta-analysis of double-blind, randomized, controlled trials comparing placebo vs oral antimicrobial for initial therapy of uncomplicated acute rhinosinusitis in patients aged 12 years or older.
Results: Thirteen trials met inclusion criteria and had data suitable for pooling. Clinical cure occurred in 8% of patients who received placebo after 3 to 5 days, rising to 35% by 7 to 12 days and 45% by 14 to 15 days. Antimicrobials increased cure rates at 7 to 12 days, with an absolute rate difference of 15% (95% CI, 4%-25%). Clinical improvement occurred in 30% of patients who received placebo after 3 to 5 days, rising to 73% by 7 to 12 days and 14 to 15 days. Antimicrobials increased improvement rates at 7 to 12 days by 14% (95% CI, 1%-28%) and at 14 to 15 days by 7% (95% CI, 2%-13%). Diarrhea and adverse events were about 80% more common in patients who received antimicrobials (P < 0.03).
Conclusions: Over 70% of patients with acute rhinosinusitis are improved after 7 days, with or without antimicrobial therapy. About 7 patients must be treated to achieve one additional positive outcome at 7 to 12 days above and beyond spontaneous resolution. Generalizability of results is limited because nearly all trials involved a primary care setting and some trials excluded patients with severe illness.