Patient characteristics and process factors associated with antipsychotic polypharmacy in a nationwide sample of psychiatric inpatients in Italy

Purpose: The present study investigated: (i) the rate of prescription of antipsychotic (AP) polypharmacy (APP) in a large, representative sample of psychiatric inpatients; and (ii) the relationship between APP prescription and the characteristics of patients and facilities. Methods: The sample included 1022 psychiatric patients scheduled to be discharged from acute inpatient facilities with drug therapies including AP. Demographic and clinical data were obtained from the treating physician or retrieved from patients' records through a standardized Patient Form. Patients were administered the 24-item Brief Psychiatric Rating Scale. Three indicators were used to describe the process of care in the facilities: a Restrictiveness score, a Standardization score, and a Treatment score. A multilevel mixed-effect logistic regression was used to predict APP using patient and facility as the variables. Results: APP was prescribed to 333 (32.5%) patients, the most common patterns being a first-generation and a second-generation AP (n=178, 17.6%) or of two first-generation APs (n=80, 7.8%). Patients with a diagnosis of schizophrenia and poorer insight into illness at admission were significantly more likely to receive APP. The availability of more complex therapeutic interventions in the facility was also associated with APP. Conclusions: In our nationwide sample of psychiatric inpatients, APP was frequently prescribed to treat the more severe patients. However, it was also associated with process of care characteristics such as delivery of more complex therapeutic interventions, and was therefore not used only to control patient behavior.