[Pharmaco-epidemiology of antipsychotic prescription practices for schizophrenic patients (1995 and 1998 cross sectional surveys)].

OBJECTIVE

The two cross-sectional surveys reported here concern the field of pharmaco-epidemiology of prescription practices. The objective is to describe and understand these practices in regard to antipsychotics and their evolution in all indications which go beyond the field of psychotic pathology. The research presented here only concerns schizophrenic pathology.

METHODOLOGY

These 2 cross-sectional surveys were carried out in public psychiatric sectors in 1995 and 1998 applying the same methodology in the same services. On a given day, in each sector, they concern all patients aged from 18 to 64 and receiving an antipsychotic prescription. A hospital unit and a consultation unit were included to take into account practices which could be different in these two places of care. A comparison was made between the 1995 stage and the 1998 one for a better understanding of evolution in practical terms. An unvaried analysis was carried out to test the differences observed between 1995 and 1998 as well as a correlation test to evaluate evolution according to age and duration.

RESULTS

The main results were as follows: the number of antipsychotics slightly decreased significantly from 1.74 (+/- 0.02) in the 1995 survey to 1.69 (+/- 0.04) in the 1998 one (p<0.05); the number of patients receiving antiparkinsonian medicines, correcting extra pyramidal effects, decreased from 60% in 1995 to 50% in 1998. The following associated factors were noted concerning prescription of antipsychotics. Women received a mean number of antipsychotics significantly lower than that of men. For each sex the mean number was lower in the 1998 survey, but not significantly so. In the two surveys, there was a positive correlation between the mean number of antipsychotics and age; it increased as the patient grew older. The mean number of antipsychotics tended to increase significantly with length of illness, in 1995 as well as in 1998. It was for the shortest periods that the mean number of antipsychotics was lowest. The mean number of antipsychotics was significantly higher in the hospital field as compared to the ambulatory. The greater was the mean number of antipsychotics, the greater was the proportion of patients who received antiparkinsonian medication. Firstly, these surveys shed light on what may underlie prescription practices such as sex and age of the patient, length of illness and the place of care. Secondly, the evolution of practices in time can be followed, taking into account the increase of knowledge concerning this subject.