[Drug consumption in diabetes mellitus (V). Pharmacoeconomics and the acceptance of the hospital changeover to insulin U100. Group for the Study of Diabetes in Tarragona].

BACKGROUND

The U100 insulin (100 units [U]/ml) in only used in a minority of Spanish hospitals and is not ordinarily evaluated. To study the convenience of converting from U40 (40 U/ml) to U100 insulin in a first level hospital, the procedure, costs and professional acceptance were analyzed after one year of experience.

SUBJECTS AND METHODS

The chronology and the transfer method are described making an interannual pharmacoeconomical comparison of costs U40/U100 based on insulin intake and injection material. The primary source of information was the computerized base of admission, pharmacy and supply. The secondary source included the obligatory registries of daily medicine sheets. Nursing staff acceptance of the new system (preloaded U100 syringes) was analyzed with a predesigned quantitative scale questionnaire.

RESULTS

In the U40 phase, 69,600 U and 8,260 syringes were used to satisfy 136 diabetics at a mean prescription of 21 U/day for 10.9 days. In the U100 phase, 92,100 U and 1,682 syringes were used for 132 admissions with a mean dose of 20 U during 8.6 days. The insulin prescribed and injected was 45.5% and 24.7%, respectively with the consumption of non injected insulin in the center being 20.8%. On taking only the fraction injected into consideration, the mean daily cost per complete treatment was lower in U100 (116/84 and 1,368/809 pesetas; p < 0.0001) representing 0.53% (U40) and 0.36% (U100) of hospital stay costs. The total cost increased by 44 ptas./patient/day during the first year of conversion. Each section of the 67 questionnaires evaluated scored from 4 (greatest acceptance) to 20 (lowest acceptance). The general mean was 6.8 +/- 1.6 with no significant differences between the section of management/manipulation of U100 devices (6.7 +/- 2.1), learning and protocol (7.3 +/- 2.6) and patient education (6.5 +/- 1.8; p = 0.07, NS).

CONCLUSIONS

Current hospital conversion to U100 insulin requires the use of mechanized injection systems which represent a slight extra cost of scarce social relevance and are greatly accepted by users if adequate transfer procedures are applied.