Cost-effectiveness study on influenza prevention in Hong Kong.

INTRODUCTION

Recent studies confirm that influenza vaccination confers health benefits and reduces direct and indirect costs associated with the illness. However, these studies did not examine the situation in southern China, a hypothetical influenza epicentre for the emergence of pandemic influenza viruses.

METHODS

Surveillance data were collected in Hong Kong in 1993/94 and used economic model was used to estimate the medical and social costs associated with influenza-like illness (ILI) and to predict the cost-effectiveness of implementing an influenza prevention programme.

FINDINGS

The estimated ILI incidence was 110/1000. It was highest in those between 1 and 25 years of age while the rate of hospitalization was highest in the elderly. Influenza occurred throughout the study period, which was a mild influenza year. The model predicted more than 660000 ILI cases in a non-epidemic year, in which influenza B virus predominated, with an average ILI-associated cost of HK$283/case (US$36) and vaccination-associated costs of HK$74 (US$9.50) per vaccinated individual.

CONCLUSION

The medical, social and monetary costs of ILI in Hong Kong were not observed to be large when compared with those in more developed countries where there is a clearly defined influenza season and recognized disease burden. From the perspective of a susceptible individual, the vaccine was cost-effective but from the perspective of society it was not, even with the most cost-effective strategy of targeting the elderly. However, if the vaccine were effective in controlling newly emerging and highly virulent strains, targeted vaccination programmes might be highly cost-effective.