[A standardized amount indicator by equivalent patient to control outpatient pharmaceutical expenditure, Spain]

The outpatient pharmaceutical expenditure in developed countries represents a huge percentage of the total health budget, because of that, it is necessary to use tools aimed to control and guarantee an efficient use of these resources. Improving the current construction of the indicator of pharmaceutical expenditure in order to have a more adjusted tool of pharmaceutical expenditure control.

We introduce the concept of "equivalent patient" in the standardization of outpatient pharmaceutical expenditure, considering in its design several socio demographic variables in order to supersede the previous model which just considered the "Co-payment status" for adjusting the outpatient pharmaceutical expenditure. We considered variables as age, sex, co-payment status and nationality to elaborate the concept of equivalent patient.

By applying the standardization method we obtained 160 groups of consumption with weights from 0,10 to 4,39 equivalent patients.

We obtained a tool capable of improving the construction of Pharmaceutical Expenditure Indicators, which are essential for the design of measures aimed to stimulate the rational use of drugs. In a micro level of analysis, the new indicator is useful to establish economic incentives aimed to encourage good performance from physicians in the prescription field.