Age-related differences in factors associated with the underuse of recommended medications in acute coronary syndrome patients at least one year after hospital discharge

BACKGROUND: Few studies have evaluated age-related predictors associated with the underuse of medications in patients with coronary heart disease (CHD). The objective of this study was to identify age-related differences in the factors associated with the underuse of recommended medications in patients diagnosed with acute coronary syndrome (ACS). METHODS: From August 2009 to April 2011, we recruited 469 consecutive ACS patients from a cardiac center at a university hospital. We divided the patients into older (65 years of age and older, n = 202) and younger groups (younger than 65 years of age, n = 267). Data on socio-demographic characteristics, depressive symptoms, and medication use were obtained from a telephone survey administered 18 to 24 months after hospital discharge. Additionally, we asked the patients to provide reasons for not taking their medications. RESULTS: A significantly increased underuse of medication was noted in older patients compared with younger patients, including aspirin (24.8% vs. 37.1%, p = 0.005), beta-blockers (20.3% vs. 34.8%, p = 0.001), ACE inhibitor/angiotensin receptor blockers (27.2% vs. 36.7%, p = 0.030), and statins (21.8% vs. 29.6%, p = 0.005). Among older patients, the factors associated with the underuse of medications included low education level (odds ratio [OR], 3.93), greater number of comorbidities (OR, 1.64), and total number of discharge medications (OR, 1.31). The reasons provided by older patients for not taking medication included the fact that the medication was considered to be non-essential and the large number of medications. Among younger patients, low income (OR, 3.97) and depression (OR, 2.62) were predictors for underuse of medication, and the reasons provided for not taking medications included high costs and the fear of adverse effects. CONCLUSIONS: At least one year after ACS hospital discharge, the underuse of recommended medications is related to low education level, comorbidities, and the total number of discharge medications in elderly patients, whereas underuse in younger patients is associated with low income and depression. The disparities related to these different predictors may have implications for age-related interventions targeting secondary preventions in CHD patients to improve their use of medication.