[Use of European Quality of Life-5 Dimensions (EQ-5D) questionnary to value the health related quality of life variation because of influenza].

OBJECTIVE

To describe self-perceived health status and health-related quality of life (HRQoL) in healthy individuals of working age, to measure changes due to influenza infection, and to evaluate the effect of influenza infection on HRQoL in monetary terms.

METHOD

We performed a descriptive observational study through questionnaires administered to 50 patients of working age infected with the influenza virus during the epidemiologic year 2004-2005 and living in private homes of the city of Logroño (Spain). The patients completed the questionnaires twice: with and without influenza. The dimensions and HRQoL indicators of the European Quality of Life-5 Dimensions (EQ-5D) questionnaire were evaluated. HRQoL utility indices were used to calculate lost quality-adjusted life years (QALYs).

RESULTS

On average, the reduction in the HRQoL utility index caused by influenza infection was between 0.37 and 0.65, on a scale from 0 (death) to 1 (perfect health). An influenza epidemic in 100,000 individuals could imply a loss of 137 QALYs, which in monetary terms could represent 2,722,609euro.

CONCLUSIONS

The EQ-5D dimension most negatively affected by influenza was <> while the least affected dimension was <<anxiety/depression>>. Influenza causes substantial losses in HRQoL among the population of working age. The results of the sensitivity analysis of the monetary effects of influenza infection yielded intervals showing a range of more than 5 times the mean value.