Annals of Internal Medicine
April 3, 2012; 156 (7)
http://www.annals.org/content/current

Antivirals for Treatment of Influenza: A Systematic Review and Meta-analysis of Observational Studies
Jonathan Hsu, Nancy Santesso, Reem Mustafa, Jan Brozek, Yao Long Chen, Jessica P. Hopkins, Adrienne Cheung, Gayane Hovhannisyan, Liudmila Ivanova, Signe A. Flottorp,
Ingvil Sæterdal, Arthur D. Wong, Jinhui Tian, Timothy M. Uyeki, Elie A. Akl, Pablo Alonso-Coello, Fiona Smaill, and Holger J. Schünemann
Ann Intern Med April 3, 2012 156:512-524; published ahead of print February 27, 2012,

Abstract
Antiviral therapy may reduce complications and mortality associated with influenza, but there have been concerns that randomized trials might not reflect that. This review of 74 observational studies found that oral oseltamivir may reduce mortality in high-risk populations compared with no treatment. Either oral oseltamivir or inhaled zanamivir might reduce hospitalizations and symptom duration. Costs and targeting strategies, however, were not evaluated. The studies focused on drug-sensitive infections, so the results may not be applicable if antiviral-resistant viruses are prevalent. Antivirals might improve outcomes in some situations, but more evidence is needed to guide decision making about when and in whom to use particular agents.