Utility and Barriers to Clozapine Use: A Joint Study of Clinicians' Attitudes From Singapore and Hong Kong.

Objective: This study aimed to survey clinicians' attitudes in Singapore and Hong Kong toward clozapine and elucidate the barriers to its prescription in patients with treatment-resistant schizophrenia. Methods: All clinicians in psychiatry in both regions were invited through email to participate in an anonymous online survey. The survey collected information on the participants' characteristics, their experience with clozapine initiation, perceived usefulness of clozapine, barriers to clozapine initiation, and factors that might improve clozapine use. Data collection took place between December 2018 and March 2019 in Singapore and September 2019 and February 2020 in Hong Kong. Results: A total of 261 clinicians (156 in Singapore, 105 in Hong Kong) responded to the survey. The majority of participants believed that clozapine was an effective and satisfactory treatment for schizophrenia. Clinicians were most concerned about the need for frequent blood monitoring (84.5% in Singapore; 87.5% in Hong Kong), clozapine's tolerability (51.9% in Singapore; 61.6% in Hong Kong), and medical complications (54.8% in Singapore; 49.1% in Hong Kong). Compared to Hong Kong, more clinicians in Singapore endorsed an underutilization of clozapine (67.9% in Singapore; 51.4% in Hong Kong) and a greater need for outpatient resources in terms of clinic and administrative support (74.4% in Singapore; 59.0% in Hong Kong) to improve clozapine prescription. Conclusions: The underutilization of clozapine in treatment-resistant schizophrenia remains a concern in both regions. An integrated clozapine service that addresses the system barriers and clinicians' confidence in prescribing clozapine and managing its adverse effects would greatly improve the utilization of clozapine.