Stroke Victim Compliance With Prescription Medication
Overview
Adherence to secondary prevention medications following an ischemic stroke or transient ischemic attack is crucial for reducing recurrence risk. This study assessed medication adherence over a three-year period post-stroke using prescription and dispensing data, and aimed to identify factors influencing suboptimal adherence.
Conducted as a multicenter, prospective cohort study, it involved patients from the STROKE 69 cohort—those admitted with suspected acute stroke between November 2015 and December 2016 in the Rhône area of France. Data were gathered on antihypertensives, antidiabetics, lipid-lowering drugs, and antithrombotics. Adherence was measured with the continuous medication acquisition index, and potential influencing factors were analyzed based on the World Health Organization’s five dimensions.
Of the 1512 patients eligible, 365 were included in the analysis. Optimal adherence (≥90%) was observed in 61%, 62%, and 65% of patients in the first, second, and third years, respectively. Factors such as a higher education level (high school diploma or above: OR = 3.24) and depression (Hospital Anxiety and Depression Scale–Depression scores of 8–10: OR = 1.90) were significantly linked to suboptimal adherence. Conversely, a history of heart rhythm disorder was associated with better adherence.
In conclusion, adherence to secondary prevention medications for stroke patients was generally good. Higher educational attainment and the presence of depression were associated with poorer adherence, while a history of heart rhythm disorders was associated with improved adherence.
Introduction
Patients who have experienced an ischemic stroke (IS) or transient ischemic attack (TIA) face a significant risk of recurrence both immediately and over their lifetime. To mitigate this risk, preventive lifestyle changes, such as quitting smoking, losing weight, and increasing physical activity, are essential. Additionally, secondary prevention medications (SPMs) play a crucial role. These medications, tailored to individual conditions and comorbidities, typically include antihypertensives, lipid-lowering agents, antithrombotics, and, if necessary, antidiabetics.
The effectiveness of these SPMs for stroke victims hinges on patient adherence, which refers to how well patients follow prescribed treatment regimens in terms of timing, dosage, and frequency. Non-adherence undermines treatment efficacy and heightens recurrence risk. A 2019 meta-analysis revealed that only 64.1% of patients adhered to their prescribed treatments, indicating a need for improvement to prevent recurrent events.
Medication adherence is influenced by various factors categorized by the World Health Organization into five dimensions: socioeconomic factors, patient-related factors, health system and healthcare team-related factors, condition-related factors, and therapy-related factors. To address these complexities, a thorough understanding and accurate measurement of adherence are essential. Traditional adherence measurement methods have often been based on self-reported data, which may not always be reliable. Our study aimed to enhance accuracy by using objective measures derived from prescription and dispensing data over a three-year period following IS/TIA. Additionally, we sought to identify factors from all five dimensions that contribute to suboptimal adherence in stroke patients.
Method
This study received approval from the Tours (France) ethics committee and the French National Commission on Data Protection (CNIL). It was registered on ClinicalTrials.gov under NCT03153020. The research was part of a multicenter, prospective study involving patients from the STROKE 69 cohort, which includes individuals suspected of acute stroke admitted to various healthcare facilities in the Rhône area of France between November 2015 and December 2016. Eligible participants were those admitted for ischemic stroke (IS) or transient ischemic attack (TIA), confirmed by imaging, and meeting additional criteria such as surviving for at least one year post-stroke, not residing in a nursing home, being capable of self-managing medication, and having no communication issues. Informed consent was required for follow-up interviews and data extraction from the national health insurance database.
Prescription data collected encompassed drug names, forms, doses, and durations for four specific medication classes: antihypertensives, oral antidiabetics, lipid-lowering drugs, and antithrombotics. These were based on the 2015 French national health authority guidelines, which aligned with international standards. Data collection included initial prescriptions at hospital discharge and subsequent self-reported medication details during follow-up interviews at 1, 2, and 3 years.
Administrative claims data for the three years following the index IS/TIA were sourced from the regional ERASME database, covering hospitalization reimbursements and community drug dispensation. Medication adherence was objectively measured using the Continuous Medication Acquisition (CMA) index, which evaluates both compliance and persistence with prescribed regimens. Adherence was calculated separately for the first year (CMA6) and the subsequent two years (CMA7) using prescription and refill data.
Potential factors affecting adherence were examined across five World Health Organization dimensions: socioeconomic, healthcare system-related, patient-related, condition-related, and therapy-related factors. These included demographic details, healthcare interactions, beliefs about medication, and clinical history.
Statistical Analysis
Statistical analyses included descriptive statistics, comparison tests, and logistic regressions to identify determinants of adherence. Sensitivity analyses were performed for education variables and adherence thresholds. All analyses utilized SAS version 9.4 and R 4.2.2.
Result
In the STROKE 69 cohort study of 2,347 patients with ischemic stroke (IS) or transient ischemic attack (TIA), 1,512 patients were eligible and invited to participate, with 365 actually included. cCMA (cumulative medication adherence) was measured for 341 patients in the first year, 251 in the second year, 208 in the third year, and 199 patients over all three years. Among these, 57.5% were admitted for IS and 42.5% for TIA. The median age was 71 years.
The median overall treatment adherence rates were 93%, 94%, and 94% in the first, second, and third years, respectively, with optimal adherence observed in 61%, 62%, and 65% of patients over these years. Among patients with data for all three years, adherence rates remained stable at around 67%, 65%, and 66% respectively. Notably, adherence to antiplatelets and lipid-lowering drugs declined significantly, while trends for antihypertensive therapies and anticoagulants showed increases.
Socioeconomic factors such as sex and age did not significantly impact adherence, though education level was associated with adherence. Those with at least a high school diploma or unknown education status had higher odds of suboptimal adherence. A significant relationship was found between depressive symptoms, measured by the Hospital Anxiety and Depression Scale-Depression (HAD-D), and adherence. Patients with higher HAD-D scores or unknown scores had increased odds of suboptimal adherence. A history of smoking showed a trend toward reduced adherence, but was not statistically significant.
Condition-related factors revealed that an initial diagnosis of ischemic stroke was linked to lower odds of suboptimal adherence compared to TIA. Additionally, a history of heart rhythm disorder was associated with better adherence. Sensitivity analyses adjusting the threshold for optimal adherence from ≥90% to ≥80% showed changes in significance levels for some factors, but the overall patterns remained consistent.
Conclusion
The study examined medication adherence in patients post-ischemic stroke (IS) or transient ischemic attack (TIA), finding generally good adherence, with nearly two-thirds of patients deemed optimal adherents in the first year. Adherence remained stable over three years, though variations were noted by therapeutic class. Antiplatelet adherence decreased from 71% in the first year to 56% in the third year, potentially due to side effects or reduced perceived need, though this rate remained higher than previously reported. Lipid-lowering drug adherence also decreased, from 82% to 64% over the same period, which may be linked to statin intolerance.
Socioeconomic and patient-related factors were significant in adherence. Surprisingly, higher education levels correlated with poorer adherence, possibly due to heightened medication concerns, contrary to initial assumptions. Depression, particularly moderate levels, was linked to poorer adherence, while history of heart rhythm disorders was associated with better adherence.
Health system and healthcare team-related factors did not significantly impact adherence in this stroke cohort. The study’s limitations include potential overestimation of adherence and a modest sample size due to non-consent and data linkage issues. The adherence threshold set at ≥90% was based on its association with optimal clinical outcomes, though sensitivity analysis suggested that this threshold moderately influenced findings.
In summary, adherence to secondary preventive medication post-stroke/TIA was generally good and stable, with specific factors influencing suboptimal adherence. Identifying these factors can help healthcare providers better manage adherence and improve patient outcomes. Future research should focus on qualitative studies to understand non-adherence reasons and intervention studies to develop strategies for improvement.