Published: Applied Health Economics and Health Policy, 2010
Background
Compliance among patients with schizophrenia is typically poor. Consequently, treatments that are equally efficacious under trial-based conditions but face different compliance rates in clinical practice (e.g. due to adverse-effect profile, ease of use, reputation) may have differences in effectiveness not observed during trials. This study analyses the impact of differences in compliance with atypical antipsychotics using a pharmacoeconomic discrete-event simulation (DES) model, adapted to the Swedish treatment setting.
Methods
An existing 5-year DES model was adapted to reflect a Swedish setting; the analysis was conducted from a third-party payer perspective, with only direct costs included. The two treatment arms were identical except for percentage of compliant patients. Non-compliant patients experienced shorter time between relapses and had inferior symptom control than their compliant counterparts. The difference in compliance rates was varied from 0% to 15%, and incremental costs and effects were recorded and analysed.
Results
With a 5%, 10% and 15% difference in compliance rate, incremental effects increased to 0.021, 0.037 and 0.062, respectively, while generating cost savings of Swedish kronor (SEK)31 500, SEK62 000 and SEK104 500, respectively (SEK9.25 = 1, Euro year 2007 values). Hence, each percentage point of compliance gain is predicted to roughly result in a cost saving of SEK6000 and a QALY gain of 0.004. On average, the model predicts that, with a 15% increase in compliance, 0.5 relapses are prevented, the average Positive And Negative Syndrome Scale (PANSS) score decreases by 3.3 points and patients spend 22 fewer days in hospital over 5 years.
