[Diabetes and pharmacoeconomics. Efficiency of insulin injection methods available in Spain].

OBJECTIVES

In Spain today there are three ways of injecting insulin, the traditional syringe (TS) and two automatic methods: injector pens (IP) and preloaded syringes (PS). The main aim of the study was to compare their efficiency in normal use; and the second, to compare their effectiveness in terms of how they suited the clinical profile and needs of the users.

DESIGN

A pharmacoeconomical study to minimise costs.

SETTING

Two Primary Care clinics, one specialising in diabetes and the other not, and a third clinic, part of hospital out-patients.

PATIENTS AND OTHER PARTICIPANTS

Systematic examination of the insulin packages and the material used by 108 diabetics (3 groups of 36, divided by the method of injection) over an average period of 51 days.

MEASUREMENTS AND MAIN RESULTS

The average dose prescribed was 34.7 units (U) per day, supplied in 2.2 injections per day. The real average dose consumed was 41.4 U per day with an average daily loss of 3.1 U per injection and average re-use of needles at 7.1 times per patient. Type 11 diabetics, older patients and those with worse eye sight used TS more often. Younger and Type 1 diabetics and those who needed more injections generally used an automatic method, in particular IP. PS seemed to be used by both types of diabetic indifferently. There were significant differences found between users of TS, IP and PS regarding the doses taken (44.6, 45.1 and 34.5 U; p < 0.03), the daily loss per injection (4.5, 3.2 and 1.4 U; (p < 0.0004) and in the re-use of needles (4.1, 7.7 and 8.1 times; p < 0.02).

CONCLUSION

If we suppose similar efficacy, automatic systems are more efficient in reality than traditional syringes and insulin vials.