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.