Low adherence also tied to cost; physician, pharmacy access;
MONDAY, Sept. 12 (HealthDay News) -- Low patient adherence to daily medication regimens before percutaneous coronary intervention (PCI) is a good predictor of low clopidogrel adherence after PCI, according to a study published in the Sept. 15 issue of The American Journal of Cardiology.
Paul Muntner, Ph.D., from the University of Alabama in Birmingham, and colleagues examined factors associated with low clopidogrel adherence 30 days after PCI in 284 patients. The eight-item Morisky Medication Adherence Scale (MMAS-8) was used to assess adherence to daily medications before PCI, and categorized as low (score, <6), medium (score, 6 to <8), or high (score, 8). Low adherence to clopidogrel was determined at an interview 30 days post-PCI.
The investigators found that 11 percent of the patients had low clopidogrel adherence 30 days post-PCI; 21 had an MMAS-8 score <6 and 11 discontinued clopidogrel. Patients who, before PCI, reported taking smaller doses of medication because of cost, had difficulty filling prescriptions, had difficulty contacting their primary physician, and were not comfortable asking for physician instructions had increased likelihood of low adherence to clopidogrel (odds ratio [OR], 3.78, 3.06, 2.46, and 3.36, respectively). Patients with medium and low adherence to daily medications before PCI were more likely to have low clopidogrel adherence post-PCI compared to those with high adherence before PCI (OR, 6.13 and 10.9, respectively). The c-statistic correlated with MMAS-8 scores before PCI for predicting low clopidogrel adherence at 30 days post-PCI was 0.733.
"Adherence to daily medications before PCI may be a useful indicator for identifying patients who will have low clopidogrel adherence after PCI," the authors write.
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