Relationships between multiple self-reported nonadherence measures and pharmacy records.
BACKGROUND
Nonadherence is a momentous problem that confounds optimal medication therapy outcomes. Measuring nonadherence presents a number of methodological conundrums. Pharmacists and other health practitioners might benefit from a simple tool for measuring adherence that correlates well with other, more systematic methods.


OBJECTIVE
To determine (1) the concordance between monthly oral 7-day self-reported nonadherence estimates and a written 7-day self-reported estimate of nonadherence at 3 months, (2) the concordance between oral and written self-reported nonadherence measures and pharmacy records, and (3) the extent to which oral and written self-reported nonadherence measures predict current and future medication nonadherence.


METHODS
Recruitment involved 8 Wisconsin community pharmacies within a large managed care organization (MCO) and 63 patients with new antidepressant prescriptions. Oral and written self-report measures were modified from the Brief Medication Questionnaire. Pharmacy records were obtained from the pharmacies and MCO.


RESULTS
Oral self-reported nonadherence estimates during weeks 4, 8, and 12 were significantly correlated with written self-reported nonadherence at week 12 (P< or =.05, week 4; P< or =.01, week 8; and P< or =.001, week 12). Oral self-reported nonadherence during weeks 8 and 12 was significantly correlated with and predictive of adherence measured via pharmacy records from months 1 to 6 (P< or =.05). Oral self-reported nonadherence at week 4 was significantly correlated to nonadherence from months 1 to 6 but only predictive of future nonadherence from months 1 to 3. Written self-report of nonadherence at week 12 was significantly correlated with and predictive of nonadherence from months 1 to 6 (P< or =.001).


CONCLUSIONS
Oral and written self-report measures have moderate to strong concordance with pharmacy records. Both self-report methods are significant predictors of medication nonadherence over 6 months. This study highlights the strong relationship between simple oral questions about medication use and current and future nonadherence. Such brief questions help identify sources of nonadherence and trigger appropriate interventions.
Rickles
Nathaniel M
NM
Department of Pharmacy Practice and Administration, School of Pharmacy, Northeastern University, 360 Huntington Avenue, 206 Mugar Life Sciences Building, Boston, MA 02115, USA. n.rickles@neu.edu
Svarstad
Bonnie L
BL
D000328:Adult; D000928:Antidepressive Agents / Q000008:administration & dosage / Q000627:therapeutic use; D003627:Data Interpretation, Statistical; D016903:Drug Monitoring / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008499:Medical Records / Q000706:statistics & numerical data*; D010594:Pharmacies; D010595:Pharmacists; D011795:Surveys and Questionnaires; D013689:Telephone; D016312:Treatment Refusal / Q000706:statistics & numerical data*
D000928:Antidepressive Agents