gms | German Medical Science

Background: Although it is widely acknowledged that long acting injectables (LAIs) are superior to oral medications in treating patients with schizophrenia in terms of re-hospitalizations (Kishimoto et. al 2013), there is limited data available for Germany. Therefore, we aim to analyze the impact of LAI treatment initiation on outcome measure such as number of hospitalizations, lengths of stay (LoS), outpatient office visits and associated costs.

Methods: Utilizing a large German claims data base, we adopt a mirror image study design to compare costs and resource utilization for the 12 months before the index date (first initiation of LAIs) and the 12 months after the index date. Patients were included who were diagnosed with schizophrenia in the period between 2012 and 2015. The database covers 5 million patients of the German statutory health insurance with an age and sex distribution that resembles that of the general population insured with statutory health insurance. To be eligible for the study cohort patients had to have an ICD-10 F20.x diagnosis in the quarter of index date or in the preceding quarter, be 18 years of age or older at the index date, had at least 365 days of continuous enrollment prior to the index date, and at least 365 days of continuous enrollment after the index date. We excluded patients with comorbidities of ADHD, epilepsy, and dementia in quarter of the index date or in a preceding quarter. We did so, because patients with those diagnoses often receive off-label antipsychotic medications.

Results: We identified 850 patients who switched from an oral medication to a LAI with mean age of 45 years. 54% of the patients were male. The following LAIs were prescribed: Haloperidol (n=96), Flupentixol (n=129), Zuclopenthixol (n=19), Fluspirilen (n=76), Olanzapin (n=76), Risperidon (n=176), Aripiprazol (n=66), Paliperidon (n=230). Overall, total annual treatment costs were reduced from 13,776 EURO in the pre-index period to 10,418 EURO after the initiation of LAIs indicating net savings of 3,358 EURO for the German healthcare system. While the acquisition costs of antipsychotics increased from 508 EURO to 3,458 EURO, we observed a considerable decrease in hospitalization costs (from 11,908 EURO to 5,345 EURO). This cost reduction was due to a decrease of days spent in hospitals (from 73 to 59 days). Costs for outpatient service slightly increased from 581 EURO to 789 EURO.

Conclusions: This is the first claims data base analysis for Germany that studied the cost impact of a treatment initiation with LAIs in a large cohort of schizophrenia patients. In line with results from other countries we found significant savings from a health insurance point of view that calls for a wider use of LAIs in Germany. A notable limitation of this study is that disease severity is not observable in claims data sets and for this reason, we are not able to fully control for potential confounders.