Patterns of, and factors associated with, atypical and typical antipsychotic prescribing by general practitioners in the UK during the 1990s

Aims: This paper estimates the rate of change in primary care prescribing of atypical antipsychotics in the treatment of schizophrenia and schizoaffective disorder and assesses the link between these changes and the individual characteristics of patients. Methods: Analyses use the UK-based General Practice Research Database for the years 1993 to 1999. Data were linked across years for each individual. A panel logistic regression model was used to identify factors influencing the choice between typical and atypical antipsychotics. Results: A total of 4,391 people were included in the dataset. Atypical antipsychotics prescribing in general practice grew from 1.8% in 1993 to 20.8% in 1999. Older patients were less likely to be prescribed an atypical as compared to a typical antipsychotic. Patients who had an inpatient stay in the previous year were over 1.5 times as likely to receive atypical antipsychotics, as were patients who had visited their GP six or more times in the previous year. Conclusions: Empirical results suggest that, over time, factors other than those warranted by the needs of patients may influence the class of antipsychotic they are prescribed. As prescribing of atypical antipsychotics increases, more evidence is needed to determine what factors are impacting upon the choice of antipsychotic medication.