[Antipsychotic Polypharmacy in the Treatment of Patients with Schizophrenia in Nine Psychiatric Hospitals of the Landschaftsverband Rheinland, Germany]

Abstract

Background: Antipsychotics are the cornerstone in the treatment of schizophrenia and are primarily recommended as monotherapy by evidence-based guidelines. Nevertheless, antipsychotic polypharmacy (APP) is prevalent in routine practice and APP is also used as a quality indicator since 2016 in quality management programs.

Objective: Based on routine data of nine psychiatric hospitals of the Landschaftsverband Rheinland (LVR)/Germany the prevalence of APP was determined and correlated with factors of routine healthcare in order to monitor the adoption of APP and to discuss its feasibility as a quality indicator.

Materials and methods: All cases with schizophrenia (ICD-10 F20.x; ≥ 18 years) discharged between June 1st, 2016, and June 1st, 2017, (in-patient and day clinic) were extracted from an established research database shared by all nine hospitals and analyzed regarding APP prevalence at the time of discharge.

Results: Based on 6,788 cases, the prevalence of APP was 55.5 % with an average of 2.4 antipsychotics (SD = 0.6) administered simultaneously. In multivariate analyses, significant predictors for APP were: gender (male > female), the number of days in hospital (long > short), involuntary treatment (no > yes) and the location of the hospital.

Conclusions: We found a high proportion of polypharmacy in inpatient schizophrenia patients and significant differences between hospitals. The use of the results as a quality indicator (criteria ≥ 2 antipsychotics) remains dependent on the background of the individual treatment courses, which cannot be adequately represented by the existing routine data. The LVR has been using the quality indicator of ≥ 3 antipsychotics since 2018, which is discussed as a more appropriate approach for future evaluations.