Antipsychotic adherence, switching, and health care service utilization among Medicaid recipients with schizophrenia

To evaluate health care resource utilization in patients with schizophrenia who continued newly prescribed antipsychotic medications, compared with those switching to different treatments.

Adults with schizophrenia in the California Medicaid (MediCal) database who initiated treatment with index medications in 1998-2001, were classified as having: 1) abandoned antipsychotic medications; 2) switched to another medication; or 3) continued with the index antipsychotic, for up to 6 months after the index date.

Of 2300 patients meeting eligibility criteria, 1382 (60.1%) continued index medications, 480 (20.9%) switched, and 438 (19.0%) abandoned antipsychotic treatment. Utilization in several resource categories occurred significantly more frequently among patients whose regimens were switched (vs those continuing index medications). These included using psychiatric (24.2% vs 14.5%; P < 0.001) or nonpsychiatric (31.5% vs 24.3%; P < 0.05) emergency services; being admitted to a hospital (10.6% vs 7.4%; P < 0.05); making nonpsychiatric outpatient hospital visits (43.3% vs 36.4%; P < 0.05) or nonpsychiatric physician visits (62.7% vs 56.4%; P < 0.05); and using other outpatient psychiatric (53.3% vs 40.7%; P < 0.001) or nonpsychiatric (82.7% vs 74.6%; P < 0.001) services.

Switching antipsychotic medications is associated with significantly increased health care resource utilization (vs continuing treatment).