(HealthDay News) — Dose and duration of therapy are associated with mortality for new antipsychotic users, according to a study published online May 10 in the Journal of the American Geriatrics Society.
Linda Simoni-Wastila, Ph.D., from the University of Maryland in Baltimore, and colleagues conducted a retrospective cohort study of Medicare beneficiaries who had a Minimum Data Set 2.0 clinical assessment completed between 2007 and 2009. The authors identified three mutually exclusive cohorts of new antipsychotic users with evidence of severe mental illness (SMI; 5,621 participants); dementia with behavioral symptoms (dementia + behavior) without SMI (1,090 participants); or delirium without SMI or dementia + behavior (2,100 participants). The dose (modified standardized daily dose [mSDD]) and duration of therapy with antipsychotic were assessed monthly.
The researchers found that mortality risk was significantly lower for new antipsychotic users with a mSDD of ≤1 versus those with a mSDD >1 (hazard ratio [HR]SMI, 0.77; HRdementia + behavior, 0.52; and HRdelirium, 0.61, respectively). Significantly lower mortality was seen with longer duration of antipsychotic use (91 to 184 days for SMI and delirium) versus short duration of use (≤30 days for SMI; ≤7 days for delirium). In the SMI cohort, the interaction between dose and duration was statistically significant (P < 0.001).
“Prescribers should monitor antipsychotic dosage throughout the course of antipsychotic treatment and customize dose and duration regimens to an individual’s indications,” the authors write.