Prescribing of Clozapine and Antipsychotic Polypharmacy for Schizophrenia in a Large Medicaid Program

Abstract

Objective: Underuse of clozapine and overuse of antipsychotic polypharmacy are both indicators of poor quality of care. This study examined variation in prescribing clozapine and antipsychotic polypharmacy across providers, as well as factors associated with these practices.Methods: Using 2010-2012 Pennsylvania Medicaid data, prescribers were identified if they wrote antipsychotic prescriptions for ten or more nonelderly adult patients with schizophrenia annually. Generalized linear mixed models with a binomial distribution and a logit link were used to examine prescriber-level annual percentages of patients with clozapine use and with long-term ($90 days) antipsychotic polypharmacy and associated characteristics of prescribers' patient caseloads, prescriber characteristics, and Medicaid payer (fee-for-service versus managed care plans).Results: The study cohort included 645 prescribers in 2010, 632 in 2011, and 650 in 2012. In 2012, the mean prescriberlevel annual percentage of patients with any clozapine use was 7% (range 0%289%), and the mean percentage of patients with any long-term antipsychotic polypharmacy was 7% (range 0%245%) (similar rates were found during 2010-2012). Prescribers with high prescription volume, a smaller percentage of patients from racial or ethnic minority groups, and a larger percentage of patients eligible for Supplemental Security Income were more likely to use both clozapine and antipsychotic polypharmacy for treating schizophrenia. Prescriber specialty and Medicaid payer were also associated with prescribers' practices.Conclusions: Considerable variation was found in clozapine and antipsychotic polypharmacy practices across prescribers in their treatment of schizophrenia. Targeting efforts to selected prescribers holds promise as an approach to promote evidence-based antipsychotic prescribing.

Patterns of prescription of antipsychotics in Qatar

“…The presence of contraindications to clozapine in individual patients, as well as the reluctance of some patients to take it (given the mandatory blood monitoring), may explain a portion of the underuse. Still, the resistance of the psychiatrists themselves towards prescribing clozapine likely accounts for most of the underuse, worldwide [28], as well as in the Arabian Gulf region [29]. The low rate of clozapine use in Qatar, contrasting with the high rate of use of two or even more APs, also suggests that AP polypharmacy is likely used as an alternative to clozapine, despite the absence of evidence to support this practice [30].…”

How and when to use clozapine

“…A recent multi‐national survey found utilization rates of clozapine range between 189.2/100 000 individuals in Finland to 0.6/100 000 in Japan , with most of the surveyed countries having utilization rates far below the approximated incidence of TRS of 100/100 000 individuals . In fact, alternatives without consistent evidence for the treatment of TRS, such as antipsychotic polypharmacy , are much more commonly used than clozapine , which delays the use of an evidence‐based interventions in these patients .…”

Temporal trends in clozapine use at time of discharge among people with schizophrenia at two public psychiatric hospitals in Taiwan, 2006–2017

“…Keeping in mind that treatment resistance is seen in up to a third of schizophrenia patients 3 , it stands to reason that around 30% of schizophrenia patients should be prescribed clozapine. In addition, clozapine is the only antipsychotic proven effective for recurrent suicidal behavior in schizophrenia patients 37 . Therefore, with an average prescription rate of only 17.6%, clozapine may have been underutilized at the two study hospitals.…”