Assessment of non-adherence to cardiovascular medications in Iraq by 8-items Morisky Medication Adherence Scale and analysis of dried blood spots
Medication non-adherence is common in chronic conditions such as cardiovascular diseases (CVD). According to the WHO, over 50% of patients are non-adherent to CVD medications, which results in poor health outcomes, hospital readmissions, high mortality rates and avoidable costs. The aim of this study was to assess medication non-adherence to target CVD medications via the eight-item Morisky Medication Adherence Scale (MMAS-8) and quantification of drug concentrations in blood microsamples collected on Whatman 903 cards and a volumetric absorptive microsampling device (VAMS) for the same patients using liquid chromatography–high resolution mass spectrometry (LCHRMS). Iraqi patients who had been taking one or more of nine commonly prescribed cardiovascular medications (amlodipine, atenolol, atorvastatin, bisoprolol, diltiazem, lisinopril, losartan, simvastatin, and valsartan) for at least six months were enrolled in this study. MMAS-8 scores for individual patients were determined, and whole blood microsamples assessed via LC-HRMS. To estimate overall medication non-adherence, MMAS-8 (score < 6) and the results of quantitative LC-HRMS analysis were compared. 303 patients were recruited for this study (mean age 54) taking an average of four CVD medications. Non-adherence assessed via MMAS-8 was 18.2%, as compared to the 49.2% determined via LC-HRMS analysis of blood microsamples. Both approaches showed no significant correlation between non-adherence and age or gender, but was significantly associated with the number of medications or tablets being taken daily. Quantitative LC-HRMS results obtained via the two microsampling methods (VAMS and 903 cards) were generally consistent and comparable, confirming good reproducibility. MMAS-8 was subject to overestimation and was unable to identify non-adherence to multiple medications in the regimens. Conversely, LC-HRMS gave valuable information about non-adherence to each medication in each patient’s regimen. In subsequent clinician-led patient interviews the main reasons for medication non-adherence were side effects, dose frequencies, complicated regimens, medication cost, patient beliefs, patient knowledge/understanding, and forgetfulness. The impact of using a combination approach of patient MMAS-8 data and objective blood drug concentration data with faceto-face interviews conducted by the specialist in Iraq has the potential to provide Iraqi clinicians with a novel approach to improving patients’ health and reducing the costs of treatment by monitoring and optimising CVD medications in routine clinical practice.
- PhD