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Assessment and Measurement of Medication Adherence: ONS PEP Oral Anti-Cancer Agents
Oncology Nursing Society (2015)
  • Sandra Spoelstra, Grand Valley State University
Significance: Oral anti-cancer agent (OA) adherence is often sub-optimal and may influence cancer treatment success. Clinicians are challenged to find ways to assess and measure adherence to OAs.
Problem & Purpose: When assessing and measuring OA adherence, it is essential to evaluate the timing, dosage, frequency, and duration of the regimen. The purpose of this paper is to report on the Oncology Nursing Society (ONS) Putting Evidence Into Practice (PEP) initiative to examine tools to assess and measure medication adherence.
Framework: Not applicable.
Methods: A review of the literature on tools using MEDLINE, the National Library of Medicine database, CINAHL, and the Cochrane Database was conducted, and tools were reviewed and critiqued.
Findings: Morisky Medication Adherence Scale (MMAS) predictive validity is 0.75 for adherence and 0.47 for nonadherence, with sensitivity of 0.81, specificity of 0.44, and floor or ceiling effects are likely.  The Adherence Estimator has sensitivity of 0.88 and specificity of 0.59. MMAS and Adherence Estimator may only be effective at predicting risk of nonadherence. The Beliefs about Medication Questionnaire (BMQ) has sensitivity and specificity below 0.50, and the  Medication Adherence Report Scale (MARS) has internal consistency of α=0.77, sensitivity of 0.53 to 0.13, specificity of 0.57 to 0.94, and are unlikely to be effective. ASK- 12® (Adherence Starts with Knowledge) has internal consistency reliability (α=0.75), test-retest reliability (r=0.79), and convergent validity (r= -0.74; p<0.001), and the Brief Adherence Rating Scale (BARS) has internal reliability (α=0.92), sensitivity (0.73), and specificity (0.74), and are likely to be effective for predicting nonadherence and measuring adherence rates. 
Implications: The MMAS, Adherence Estimator, ASK-12, and BARS may be useful at predicting risk of medication nonadherence, and ASK-12 and BARS may be useful for measuring rates of adherence. Nurses need to assess and measure whether a patient is following the OA regimen as prescribed. Future research needs to focus on testing tools that are sensitive and specific to cancer patients prescribed OAs. Tools could be modified to a specific clinical setting, and used in a standardized format to assess risk of medication nonadherence and measure OA adherence rates.
Publication Date
Summer 2015
Citation Information
Sandra Spoelstra. "Assessment and Measurement of Medication Adherence: ONS PEP Oral Anti-Cancer Agents" Oncology Nursing Society (2015)
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