There is a need for standardising influenza-related cost components so that the economic burden of seasonal influenza virus infections and influenza pandemics can be assessed across lower- and middle-income countries (LMIC), according to authors of a systematic review published in Vaccine.

An all-language literature search across five databasesFootnote 1 was used to identify cost analyses on seasonal influenza infections, influenza-like illnesses or pandemic influenza conducted between 1950 and 2013.

Of 62 studies identified, most were from the Caribbean, East Asia, Latin America or the Pacific. Only 39 studies provided quantitative data on direct costs, 12 studies reported productivity costs, and 19 studies reported social and economic impacts. Of 21 cost-effectiveness or cost-benefit analyses, only four met all six quality criteria.

Direct costs were lower in patients with influenza in LMIC than in high-income countries and productivity losses were higher. Studies on the social and economic impacts of influenza assessed the impact on the national economy, access to health services, medical insurance policies, investment choices made by national policy makers and international donors, and legal provisions and the security of the country with regard to measures around pandemic outbreaks.

"There is a strong need for standardizing research, data collection and evaluation methods for both direct and indirect cost components," concluded the authors. "In order to be able to make . . . comparisons robust, economic burden studies of influenza need to reflect a consensus set of guidelines about methodological approaches to cost estimation. The WHO is currently consulting on developing such tools and we plan to test them in selected pilot countries from different regions where burden of influenza disease studies are planned or ongoing, for example under the WHO Pandemic Influenza Preparedness (PIP) Framework," they said.