April 1, 2004 -- Less than half of the more than 2 million Americans living with schizophrenia are taking their antipsychotic medications as directed, a new study shows.
Despite recent improvements in drugs available to treat the potentially devastating condition, researchers found that only 41% of people with schizophrenia take their antipsychotic medications regularly.
But researchers say they were surprised to find that not only do many patients fail to take their drugs on a regular basis, nearly one in five may be overmedicating themselves by filling their prescriptions more frequently than prescribed.
The study also showed that outpatient and hospital medical costs were significantly higher in the schizophrenia patients who did not take their medications as directed.
Schizophrenia Patients Seldom Follow Doctor's Orders
In the study, which appears in the April issue of the American Journal of Psychiatry, researchers looked at prescriptions for oral antipsychotic medications filled by 1,600 schizophrenia patients who received treatment from San Diego County Adult Mental Health Services.
After analyzing prescription records, researchers divided the patients into four groups based on how often they took their medications as directed:
- Non-adherent: 24%
- Partially adherent: 16%
- Adherent: 41%
- Excess fillers:19%
Researchers found that a little more than half of the excess fillers who refilled their prescriptions more often than necessary were using multiple antipsychotic medications.
Failure to Comply Increases Medical Costs
The study also showed that medication adherence was strongly associated with medical costs. Schizophrenic patients who were non-adherent were 2.5 times more likely to be hospitalized than those who were adherent.
Patients who were partially adherent were 80% more likely to be hospitalized than those who took their medications as prescribed.
"Estimating the medical costs of non-adherence might also provide an incentive for insurers to allocate resources to improve adherence in patients with schizophrenia," says researcher Dilip Jeste, MD, a professor of psychiatry and neurosciences at the University of California, San Diego, in a news release. "Hospital expenditures, for example, are more than three times higher among those who are non-adherent than are expenditures for patients who take their medication on schedule."
Medication Use Linked to Living Situation
In addition, the study showed that adherence was closely related to the patient's living situation.
The highest rates of compliance were among those that lived with family or in an assisted living facility. But the more than half of the study participants who were living independently or homeless were much less likely to take their medications as directed.
"Of course, those living independently or homeless are least likely to receive medication supervision, to have the support of family members, and to have access to outpatient care," says Jeste.
Researchers say the results indicate a need for increased interventions to help people with schizophrenia take their medications as prescribed.