Predictors of Low Clopidogrel Adherence Following Percutaneous Coronary Intervention (original) (raw)

2011, The American Journal of Cardiology

Few data are available on factors associated with low adherence or early clopidogrel discontinuation following percutaneous coronary intervention (PCI). Patients (n=284) were evaluated prior to hospital discharge following PCI to identify factors associated with low adherence to clopidogrel 30 days later. Pre-PCI adherence to daily medications was assessed using the 8-item Morisky Medication Adherence Scale (MMAS-8) and categorized as low, medium, or high (scores <6, 6 to <8 and 8, respectively). Low adherence to clopidogrel was defined as a MMAS-8 score < 6 (n=21) or having discontinued clopidogrel (n=11), both ascertained during a 30-day post-PCI interview. At 30 days post-PCI, 11% of patients had low adherence to clopidogrel. The odds ratios (95% confidence interval) for low adherence to clopidogrel was 3.78 (1.09-13.1), 3.06 (1.36-6.87), 2.46 (0.97-6.27) and 3.36 (0.99-11.4) for patients who reported, prior to PCI, taking smaller doses of medication due to cost, had difficulty filling prescriptions, had difficulty reaching their primary physician and were not comfortable asking their doctor for instructions, respectively. The odds ratios (95% CI) for low clopidogrel adherence following PCI among patients with medium and low, versus high adherence, to daily medications prior to PCI was 6.13 (1.34-28.2) and 10.9 (2.46-48.7), respectively. The c-statistic associated with pre-PCI MMAS-8 scores for discriminating low clopidogrel adherence at 30 days post-PCI