Full Text Full Text (PDF) Table Alert me when this article is cited Alert me if a correction is posted Citation Map Email this article to a Colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to My Articles & Searches Download to citation manager Citing Articles via Google Scholar Articles by Pfeiffer, P. N. Articles by Valenstein, M. Search for Related Content PubMed Citation Articles by Pfeiffer, P. N. Articles by Valenstein, M. Veterans Atypical Neuroleptics Conventional Neuroleptics Schizophrenia Spectrum Disorders

Dosing Frequency and Adherence to Antipsychotic Medications

Dr. Pfeiffer, Dr. Valenstein, and Ms. Ganoczy are affiliated with the Serious Mental Illness Treatment Research and Evaluation Center, Department of Veterans Affairs, Ann Arbor, Michigan. Dr. Pfeiffer and Dr. Valenstein are also with the Department of Psychiatry, University of Michigan, Ann Arbor. Send correspondence to Dr. Pfeiffer at SMITREC/VA Ann Arbor Center for Excellence, P.O. Box 130170, Ann Arbor, Michigan 48113-0170 (e-mail: ppfeiffe{at}med.umich.edu). An earlier version of this study was presented at the annual meeting of the American Psychiatric Association, May 19–24, 2007, San Diego.

OBJECTIVES: This study investigated whether dosing frequency affects antipsychotic medication adherence among patients with schizophrenia. METHODS: Databases from the Department of Veterans Affairs were used to assess adherence among patients with a diagnosis of schizophrenia. Adherence was measured by using antipsychotic medication possession ratios (MPRs). Adherence was compared among patients who experienced an increase or decrease in dosing frequency and among patients on stable regimens of once-daily or more than once-daily dosing. RESULTS: Among patients with a dose increase (N=1,639), those with increases in dosing frequency (N=258) had a mean change in MPRs of -.105, compared with -.002 for those without a dosing frequency change (N=1,381) (p<.001). Patients with decreases in dosing frequency (N=1,370) had a small but significant increase in mean MPRs (MPR change=.045) when compared with 2,740 patients without a dosing frequency change (MPR change=-.018) (p<.001). Among patients on stable regimens (N=32,612), there were no significant differences in MPRs between those receiving once-daily dosing (MPR=.80) and those receiving more than once-daily dosing (MPR=.80). CONCLUSIONS: Among patients on less stable dosing regimens, increases in dosing frequency may result in modest decreases in adherence.

Get information about faster international access.

Privacy Policy

Copyright © 2008 American Psychiatric Association. All rights reserved.

Home | Search | Current Issue | Past Issues | Subscribe | All APPI Journals | Help | Contact Us