Using tests for interaction, we analyzed the primary outcome of AKI in the following 4 prespecified subgroups: antipsychotic drug type (quetiapine, risperidone, or olanzapine);antipsychotic drug dose (high or low [high dose was defined by a higher-than-median starting daily dose for
the study cohort [25 mg/d for quetiapine, 0.5 mg/d for risperidone, and 2.5 mg/d for olanzapine]); evidence of chronic kidney disease; and residential status (community-dwelling or long-term care).