A scoping review of studies comparing the medication event monitoring system (MEMS) with alternative methods for measuring medication adherence

Different methods are available for measuring medication adherence. In this paper, we conducted a scoping review to identify and summarize evidence of all studies comparing the Medication Event Monitoring System (MEMS) with alternative methods for measuring medication adherence. A literature search was performed using the open database www.iAdherence.org that includes all original studies reporting findings from the MEMS. Papers comparing methods for measuring adherence to solid oral formulations were included. Data was extracted using a standardized extraction table. A total of 117 articles fulfilled the inclusion criteria, including 251 comparisons. Most frequent comparisons were against self-report (n = 119) and pill count (n = 59). Similar outcome measures were used in 210 comparisons (84%), among which 78 used dichotomous variables (adherent or not) and 132 used continuous measures (adherence expressed as percentage). Furthermore, 32% of all comparisons did not estimate adherence over the same coverage period and 44% of all comparisons did not use a statistical method or used a suboptimal one. Only eighty-seven (35%) comparisons had similar coverage periods, similar outcome measures and optimal statistical methods. Compared to MEMS, median adherence was grossly overestimated by 17% using self-report, by 8% using pill count and by 6% using rating. In conclusion, among all comparisons of MEMS versus alternative methods for measuring adherence, only a few used adequate comparisons in terms of outcome measures, coverage periods and statistical method. Researchers should therefore use stronger methodological frameworks when comparing measurement methods and be aware that non-electronic measures could lead to overestimation of medication adherence.

Effect of Adherence to Oral Anticoagulants on Risk of Stroke and Major Bleeding Among Patients With Atrial Fibrillation

BACKGROUND

In comparison to warfarin, non-vitamin K antagonist oral anticoagulants (NOACs) have the advantages of ease of dosing, fewer drug interactions, and lack of need for ongoing monitoring. We sought to evaluate whether these advantages translate to improved adherence and whether adherence is associated with improved outcomes in patients with atrial fibrillation.

METHODS AND RESULTS

We performed a retrospective cohort analysis by using a large US commercial insurance database to identify 64 661 patients with atrial fibrillation who initiated warfarin, dabigatran, rivaroxaban, or apixaban treatment between November 1, 2010, and December 31, 2014. During a median of 1.1 y of follow-up, 47.5% of NOAC patients had a proportion of days covered of ≥80%, compared with 40.2% in warfarin patients (P<0.001). Patients with CHA2DS2-VASc (risk based on the presence of congestive heart failure, hypertension age 65-74 y, age ≥75 y, diabetes mellitus, prior stroke or transient ischemic attack, vascular disease, sex category) score ≥4 were at increased risk of stroke when they were not taking anticoagulation ≥1 month versus <1 week (1-3 months: hazard ratio [HR] 1.96, 3-6 months: HR 2.64, ≥6 months: HR 3.66; all P<0.001). Patients with CHA2DS2-VASc score 2 or 3 were at increased risk of stroke when they were not taking anticoagulation ≥6 months (HR 2.73, P<0.001). In these patients with CHA2DS2-VASc score ≥2, nonadherence was not associated with intracranial hemorrhage. Among patients with CHA2DS2-VASc score 0 or 1, time not taking anticoagulation was not associated with stroke, but not taking anticoagulation ≥3 months was associated with a significant reduction of bleeding.

CONCLUSIONS

Adherence to anticoagulation is poor in practice and may be modestly improved with NOACs. Adherence to therapy appears to be most important in patients with CHA2DS2-VASc score ≥2, whereas the benefits of anticoagulation may not outweigh the harms in patients with CHA2DS2-VASc score 0 or 1.

Trends in antithrombotic drug use and adherence to non-vitamin K oral anticoagulants in the Netherlands

BACKGROUND

Non-vitamin K oral anticoagulants (NOACs) became available in the Netherlands in 2008, providing another antithrombotic treatment besides vitamin K antagonists (VKAs) and antiplatelet agents (APAs).

OBJECTIVE

To describe the patterns of antithrombotic drug use between 2008 and 2013 by examination of dispensing data form community pharmacies in the Netherlands; to determine the concomitant use of NOACs with VKAs and APAs and switching between the drug classes; and to compare adherence to NOACs with adherence to APAs.

SETTING

An observational retrospective study was conducted using routinely collected dispensing data from Dutch community pharmacies.

METHODS

For each calendar year, the numbers of NOAC, VKA, and APA users were calculated. Adherence was determined for NOACs and APAs by the percentage of days covered by medication (PDC). Information on the prescribed daily dose of VKAs was unavailable.

MAIN OUTCOME MEASURES

Comparison of age, sex, and co-medications of users of the three drug classes; concomitant use of different antithrombotic drug classes and switching between these in each year; and mean PDC and percentages of all users with a PDC above 80 %.

RESULTS

NOAC use increased during the study period to 29,687 users in 2013. In that year there were 484,024 VKA users and 1313,032 APA users. Compared with users of VKAs, NOAC users were slightly younger and more frequently used antiarrhythmic drugs and beta blockers as co-medications. Substantial numbers of patients were dispensed potentially harmful combinations in 2013: 820 subjects were dispensed NOACs together with VKAs, and 684 subjects were dispensed NOACs, VKAs, and APAs concomitantly. Mean adherence to NOACs was 84.2 % compared with 87.3 % to APA. One in four NOAC users had a PDC lower than 80 % compared with one in five APA users.

CONCLUSION

Our findings show increasing use of NOACs by outpatients. The number of patients taking potentially harmful combinations of antithrombotic drugs was substantial. Adherence to NOACs in daily practice may be suboptimal to prevent thrombotic events.

Stroke Prevention in Atrial Fibrillation - The Use of NOACs in Everyday Clinical Practice

Non-antivitamin K oral anticoagulants (NOACs) have recently emerged as a new class of antithrombotic drugs. Four large-scale, randomised controlled trials (RCT) accredited dabigatran, rivaroxaban and edoxaban with evident advantages for stroke prevention in atrial fibrillation (AF) compared with warfarin. The superiority concerns not only the manageability but also the antithrombotic efficacy and safety. Aspects of real-life clinical experience with NOAC for stroke prevention in AF are analysed in an attempt to underline some practical differences. If at present the individualisation of the NOAC class drugs is still a subject of debate it is probable that in the near future we will be able to adapt the drug and dosages to individual patient's profile.

Edoxaban: a review in nonvalvular atrial fibrillation

The factor Xa inhibitor edoxaban (Lixiana(®)) is a new direct oral anticoagulant recently approved in the EU for the prevention of stroke and systemic embolic events (SEE) in patients with nonvalvular atrial fibrillation and one or more risk factors. In the large, randomized, double-blind, double-dummy, ENGAGE AF-TIMI 48 trial, oral edoxaban dosages of 30 and 60 mg once daily for a median treatment duration of 907 days in patients with moderate-to-high-risk nonvalvular atrial fibrillation were noninferior to warfarin for the incidence of first stroke or SEE. Both high-dose and low-dose edoxaban were associated with significantly lower rates than warfarin of major bleeding, including intracranial haemorrhage, and death from cardiovascular causes. Edoxaban has a rapid onset of action, a short half-life, few drug interactions and offers the convenience of oral, once-daily, fixed-dose administration, without the need for coagulation monitoring and without regard to food. Therefore, edoxaban is an effective and well tolerated therapeutic option in patients with nonvalvular atrial fibrillation.

Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation

The current manuscript is an update of the original Practical Guide, published in June 2013[Heidbuchel H, Verhamme P, Alings M, Antz M, Hacke W, Oldgren J, et al. European Heart Rhythm Association Practical Guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation. Europace 2013;15:625-51; Heidbuchel H, Verhamme P, Alings M, Antz M, Hacke W, Oldgren J, et al. EHRA practical guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation: executive summary. Eur Heart J 2013;34:2094-106]. Non-vitamin K antagonist oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with non-valvular atrial fibrillation (AF). Both physicians and patients have to learn how to use these drugs effectively and safely in clinical practice. Many unresolved questions on how to optimally use these drugs in specific clinical situations remain. The European Heart Rhythm Association set out to coordinate a unified way of informing physicians on the use of the different NOACs. A writing group defined what needs to be considered as 'non-valvular AF' and listed 15 topics of concrete clinical scenarios for which practical answers were formulated, based on available evidence. The 15 topics are (i) practical start-up and follow-up scheme for patients on NOACs; (ii) how to measure the anticoagulant effect of NOACs; (iii) drug-drug interactions and pharmacokinetics of NOACs; (iv) switching between anticoagulant regimens; (v) ensuring adherence of NOAC intake; (vi) how to deal with dosing errors; (vii) patients with chronic kidney disease; (viii) what to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a risk of bleeding?; (xi) management of bleeding complications; (x) patients undergoing a planned surgical intervention or ablation; (xi) patients undergoing an urgent surgical intervention; (xii) patients with AF and coronary artery disease; (xiii) cardioversion in a NOAC-treated patient; (xiv) patients presenting with acute stroke while on NOACs; and (xv) NOACs vs. VKAs in AF patients with a malignancy. Additional information and downloads of the text and anticoagulation cards in >16 languages can be found on an European Heart Rhythm Association web site (www.NOACforAF.eu).

Adherence to and persistence with non-vitamin K-antagonist oral anticoagulants: does the number of pills per day matter?

Once daily dosing schedule is associated with increased adherence to and persistence with cardiovascular therapies. Such feature has been claimed responsible for the significantly lower (both temporary and permanent) discontinuation of oral anticoagulation with rivaroxaban (which is given once daily) compared to dabigatran (which is given twice daily) in a large, real-world dataset of patients with atrial fibrillation (AF) in the United States. While a cause-effect relationship between dosing schedule and adherence and persistence could not be established, the above finding supports nonetheless the preferential selection of the non vitamin-K-antagonists oral anticoagulant (NOAC) with the easiest and most convenient regimen. Given however, the differences in efficacy and safety observed with the various NOACs compared to warfarin in the phase III clinical trials in non-valvular AF, careful individualization of treatment should be pursued, being dosing schedule only one of the variables to be taken into account. Maximal effort instead, should be put in implementing measures to enhance patient's adherence to and persistence with treatment.