Medication Dosing Schedules, Medication Knowledge, and Dosing Errors of Adults Taking Complex Drug Regimens

This study examined how patients take complex medication regimens at home. Participants were primary care patients, 21 years or older, and prescribed three or more medications. Interviews assessed medication dosing schedules, medication knowledge, and dosing errors. Participants (N=441) were middle aged (mean 56.9); the majority were Hispanic/Latino (73.4%), had limited English proficiency (59.0%), and had limited health literacy (89.0%). One in five participants dosed medication five or more times per day, although no participants in the sample had a label instructing them to take medication more than times times daily. On average, participants correctly identified the purpose of 65% of their medications. Half of participants made one or more dosing errors. Less than high school education and a regimen size of six or more medications were independently associated with less medication knowledge, whereas language discordant label instructions were associated with dosing errors. Screening for regimen dosing complication and interventions to simplify dosing schedules are needed.