[Mathematical models for economic evaluation: dynamic models based on differential equations].

The joint utilization of both decision trees and epidemiological models based on differential equations is an appropriate method for the economic evaluation of preventative interventions applied to infectious diseases. These models can combine the dynamic pattern of the disease together with health resource consumption. To illustrate this type of model, we adjusted a dynamic system of differential equations to the epidemic behavior of influenza in Spain, with a view to projecting the epidemiologic impact of influenza vaccination.

[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.

Dynamic modelling of infectious diseases: an application to the economic evaluation of influenza vaccination.

Objective: To evaluate the economic efficiency of influenza vaccination using both dynamic and static modelling approaches.

Setting: The Spanish National Health System.

Design And Methods: We modelled the progress of an influenza epidemic in Spain according to the epidemiological pattern of susceptible-->infective-->resistant, employing a non-linear system of ordinary differential equations that enables the measurement of epidemiological effects of an anti-influenza vaccination.