Ethnic Differences in Post-Stroke Medication Adherence

Background: Post-stroke medication adherence reduces stroke recurrence risk. We assessed ethnic differences in medication adherence 3 months post-stroke in a population-based study, as possible explanation for the increased stroke recurrence risk in Mexican Americans (MAs) compared with non-Hispanic whites (NHWs). Methods: Stroke cases during 2008-2015 from the Brain Attack Surveillance in Corpus Christi (BASIC) project in Texas, USA were followed prospectively for three months post-stroke to assess medication adherence. Medications in five drug-classes were analyzed: statins, anti-platelets, anticoagulants, antihypertensives, and anti-depressants. For each drug class, patients were considered adherent if they reported never missing a dose in a typical week. Chi-square or Kruskal-wallis non-parametric tests were used for ethnic comparisons of demographics, risk factors and medication adherence. Multivariable logistic regression models were constructed for the association of ethnicity and medication adherence. Results: This study included 781 MAs and 477 NHWs. MAs were younger (median 66 years versus 70 years, p<0.001) and had more diabetes (p<0.001), and hypertension (p<0.001) and less atrial fibrillation (p <0.001) and smoking (p=0.002) than NHWs. Sex, insurance status, high cholesterol, previous stroke history, smoking status, excessive alcohol use, tPA treatment, NIHSS score, and comorbidity index did not significantly differ by ethnicity. There was no significant difference in medication adherence for any of the five drug classes between MAs and NHWs (table). The multivariable models showed only older age consistently associated as protective of non-adherence. Conclusions: Medication non-adherence is common and a potential important target for reducing stroke recurrence rates. This study did not find ethnic differences in medication adherence. Other reasons for the excessive stroke recurrence burden in MAs should be explored.