OBJECTIVES : To characterize the economic burden of 2009 pandemic H1N1 influenza in mainland China through a systematic review and modelling study.

METHODS : We used below terms to search the economic burden per capita and number of patients published between 2009 to 2020 in PubMed, Web of science, CNKI, and Wanfang, including “influenza A H1N1”, “pandemic”, “cost”, “economic”, “burden”, “China”. We pooled the costs per capita attributable to 2009 pandemic H1N1 influenza. For the provinces without data, we extrapolated the pooled results weighted by region-specific GDP per capita. Then a multiplier model was built to estimate the national economic burden of the pandemic.

RESULTS : We identified 16 economic studies in Chinese and English. Of 13 studies, the study participants were lab-confirmed cases of 2009 pandemic H1N1 influenza. The direct medical cost of outpatients was CNY 45-381 per capita, and CNY 2,347-16,936 for inpatients. 4 studies reported the cost per capita in different clinical subtypes. The direct cost of mild outpatients and mild inpatients was CNY 303-357, and CNY 4,282, respectively. The direct cost of severe/critical cases was CNY 13,754-19,739, and CNY 50,955 for fatal cases. The indirect cost per capita was CNY 963 for outpatients, and CNY 1,059-5,596 for inpatients. By extrapolating these estimates to the national level, the adjusted outpatient cost per capita was CNY 528, and that of inpatients was CNY 9,950 in China. As of July 4, 2010, a total of 127,885 lab-confirmed cases were reported, among which 31,615 were hospitalized. We estimated that the total costs were over CNY 365 million.

CONCLUSIONS : Considering the direct and indirect cost, 2009 pandemic H1N1 influenza caused heavy economic burden in mainland China. The economic burden of inpatients is much higher than that of outpatients. Better preparedness towards influenza is needed to prevent the impacts of potential pandemic in the future.