Relationships between multiple self-reported nonadherence measures and pharmacy records

• Published in: Research in social and administrative pharmacy Vol. 3; no. 4; pp. 363 - 377
• Main Authors: Rickles, Nathaniel M., Svarstad, Bonnie L.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-12-2007
• Subjects: Adherence; Adult; Antidepressants; Antidepressive Agents - administration & dosage; Antidepressive Agents - therapeutic use; BMQ; Data Interpretation, Statistical; Drug Monitoring - statistics & numerical data; Female; Humans; Linear Models; Male; Medical Records - statistics & numerical data; Pharmacies; Pharmacists; Pharmacy records; Self-report; Surveys and Questionnaires; Telephone; Treatment Refusal - statistics & numerical data; Adherence; Pharmacy records; Antidepressants; Self-report; BMQ
• ISSN: 1551-7411; 1934-8150
• DOI: 10.1016/j.sapharm.2006.11.001

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.
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.
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.
Oral self-reported nonadherence estimates during weeks 4, 8, and 12 were significantly correlated with written self-reported nonadherence at week 12 (
P
≤
.05, week 4;
P
≤
.01, week 8; and
P
≤
.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
≤
.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
≤
.001).
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.