Antipsychotic use among persons with schizophrenia in Sweden and Finland, trends and differences

OBJECTIVES: To compare the differences in prevalence of antipsychotic and adjunctive pharmacotherapy use among individuals with schizophrenia between Sweden and Finland during 2006-2016. METHODS: Nationwide register-based data were utilized for constructing two separate cohorts: all persons in Finland with a diagnosis of schizophrenia treated in inpatient care during 1972-2014, and persons in Sweden aged 16-64 with recorded diagnoses of schizophrenia in inpatient or specialized outpatient care, sickness absence or disability pension during 2005-2013. The prevalence of use was assessed as a point prevalence on 31 October each year 2006-2016, based on drug use periods modelled with the PRE2DUP method. In 2016, the Finnish cohort included 37,780 persons and Swedish cohort 25,433 persons. RESULTS: The most commonly used antipsychotic in 2016 was oral olanzapine in both countries (22.7% [95% CI 21.6-22.4] in Finland, 20.9% [20.4-21.4] in Sweden), followed by clozapine which was more frequently used in Finland (22.0%, 21.6-22.4) than in Sweden (14.8%, 14.4-15.3). Long-acting injectable (LAI) use was almost two times more likely in Sweden (21.6%, 95% CI 21.1-22.1) than in Finland (12.8%, 12.5-13.1), a difference which was due to more common use of FG-LAIs in Sweden. A four-fold difference was observed in Z-drugs use (19.9% in Sweden versus 5.0% in Finland). CONCLUSION: Potential explanations for the observed discrepancies include differences in national treatment guidelines, methods of data collection, patient characteristics and/or attitudes towards treatment among both patients and physicians.