Uno studio di drug utilisation delle statine nella recente prassi terapeutica italiana

Summary

Introduction

Cardiovascular diseases remain the major cause of death in the world, with extensive public health expenditures. Lipid lowering agents are widely used for prevention, among which statins are dominant. The statins market is steadily expanding in Italy. It is however possible that some prescriptions are not justified; as well as, on the other hand, that consumption does not meet the necessary compliance. Confronting such questions, the present work performs a drug utilisation study of statins in Italy, according to current practices and in the perspective of the compliance to treatment.

Materials and methods

Observational data were collected in a Health Unit located in Northern Italy, via its administrative database. Patients were considered eligible who had received at least one prescription of statins in the course of the five years period 2000–2004. The drug utilisation was evaluated year by year and in different ways, that is: 1) by the RDD (Received Daily Dose), which is an indicator of the average quantity of drug actually received by a patient; 2) by the PDD (Prescribed Daily Dose), an indicator of the intention to treat by the practitioner in charge; 3) by the number of days of treatment per year, calculated based both on DDDs (Defined Daily Dose, i.e. the World Health Organisation standard for the daily intake of a drug) and PDDs.

Results

40,583 patients were recruited (mean age 61 years, 47% males). A 44% drop-out was assessed among patients in their first year of treatment. Average RDDs resulted generally lower than the respective DDDs, all RDDs showing a positive growth trend. The same positive trend was observed with PDDs, which, on the other side, were always higher than the respective DDDs. The general average value for days of treatment was 248 (when calculated based on DDDs). Also such parameter was steadily, substantially growing along the years of the observation period. The analysis of compliance (measured in terms of days of treatment as percent of 365 days in a year) showed that the share of patients was decreasing with a compliance until 50%, constant with a compliance 50 to 75%, and increasing with a higher compliance.

Discussion and conclusions

Several studies are available where compliance is estimated with reference to one point in time (e.g. one year). Though valuable, this is static information. On the contrary, a potential contribution by the present study is in having analysed the drug utilisation of statins also in its dynamics, so providing data not only about levels but also about trends. On this issue, one could agree there is a general, positive tendency in Italy towards a more correct treatment practice; this is shown by drug utilisation increasing levels, which are approaching those recommended for therapeutical efficacy.