Effects of medication adherence on hospitalizations and healthcare costs in patients with schizophrenia in Thailand.

BACKGROUND This study was conducted to determine the impacts of medication adherence on hospitalization and direct healthcare cost in patients with schizophrenia in Thailand. METHODS A retrospective study was undertaken. Patients with schizophrenia aged 18-65 years who visited a University hospital and received antipsychotics from April 2011 to October 2011 were included. Propensity score-adjusted logistic regression was used to determine the impacts of medication adherence on schizophrenia-related and all-cause hospitalizations. RESULTS A total of 582 patients were included. Three out of 224 patients (1.3%) were hospitalized with schizophrenia in optimal adherence group, while 10 of 140 (7.1%) were hospitalized in under-adherence group, and 7 of 218 (3.2%) were hospitalized in over-adherence group. Based on propensity score-adjusted multivariate logistic regression, the adjusted odds ratio was 5.86 (95% confidence interval = 1.53-22.50) for schizophrenia-related hospitalization and 8.04 (95% confidence interval = 2.20-29.40) for all-cause hospitalization. The average annual direct healthcare costs in patients with optimal adherence, under-adherence, and over-adherence were US$371 ± US$836, US$386 ± US$734, and US$508 ± US$2168, respectively. CONCLUSION An initiation of interventions to maintain optimal adherence in patients with schizophrenia would significantly impact the healthcare system.