Nursing Strategies for Improving Adherence to Anticoagulation Therapy in Atrial Fibrillation Patients

Introduction

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia encountered in clinical practice and is associated with a substantially elevated risk of ischemic stroke, largely attributable to thrombus formation within the fibrillating left atrium. Oral anticoagulant therapy, whether delivered through a vitamin K antagonist such as warfarin or through one of the direct oral anticoagulants (DOACs), reduces stroke risk by approximately two-thirds when taken consistently and as prescribed (Kirchhof et al., 2016). Despite this well-established efficacy, real-world adherence to anticoagulation therapy remains disappointingly low, with published estimates of non-adherence ranging from 20% to 60% depending on the anticoagulant class, measurement method, and follow-up duration.

Non-adherence to anticoagulation carries distinct and asymmetric risks depending on its direction. Missed or delayed doses restore thrombotic risk and increase the likelihood of stroke or systemic embolism, while excessive or duplicated dosing, sometimes arising from confusion between anticoagulant regimens, increases bleeding risk. Unlike many chronic disease medications, anticoagulants therefore demand a particularly narrow margin of adherence error, and the consequences of non-adherence are frequently severe, irreversible, and costly (Shore et al., 2014). The transition from warfarin, which requires frequent laboratory monitoring and dose titration, to fixed-dose DOACs has reduced the monitoring burden on patients but has also removed a built-in touchpoint that previously prompted regular clinical contact and informal adherence reinforcement.

Nurses are uniquely positioned within the anticoagulation care pathway. They typically deliver initial patient education at the time of diagnosis or hospital discharge, coordinate anticoagulation clinic visits, conduct medication reconciliation, and serve as the primary point of contact for patients experiencing side effects, dosing confusion, or concerns about bleeding risk. This sustained and trusted relationship positions nursing staff to identify early signs of non-adherence and to intervene before a missed dose translates into an adverse clinical event (Clarkesmith et al., 2013). A substantial body of intervention research has consequently examined whether structured, nurse-delivered adherence programs, ranging from single educational sessions to sustained multicomponent coaching models, meaningfully improve adherence and downstream clinical outcomes. However, this literature varies considerably in intervention intensity, delivery format, and outcome measurement, leaving a fragmented picture of which nursing strategies are most effective. The purpose of this systematic review was to synthesize evidence on nurse-delivered interventions to improve anticoagulation adherence among patients with atrial fibrillation and to identify the intervention characteristics most consistently associated with improved adherence and clinical outcomes.

Methods

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. The review question was structured using the Population, Intervention, Comparison, Outcome (PICO) framework: adults with a diagnosis of atrial fibrillation prescribed oral anticoagulation (population); a structured intervention delivered primarily by a registered nurse or nurse practitioner (intervention); usual care or standard anticoagulation clinic follow-up (comparison); and medication adherence, persistence, or anticoagulation-related clinical events, including stroke, systemic embolism, and major bleeding (outcomes).

A systematic search was conducted across four electronic databases, MEDLINE, CINAHL, Embase, and the Cochrane Central Register of Controlled Trials, for studies published between January 2010 and March 2025. Search terms combined controlled vocabulary and free-text terms related to atrial fibrillation, anticoagulation, medication adherence, and nursing intervention, connected with Boolean operators. Reference lists of included studies were hand-searched to identify additional eligible reports.

Studies were included if they met the following criteria:

1.Enrolled adults with a confirmed diagnosis of atrial fibrillation who were prescribed a vitamin K antagonist or a direct oral anticoagulant for stroke prevention.

2.Evaluated a structured intervention delivered primarily by nursing staff, including education, coaching, telephone or remote monitoring follow-up, or a combination of these components, compared against usual care using a randomized, quasi-experimental, or prospective cohort design.

3.Reported at least one quantifiable adherence, persistence, or anticoagulation-related clinical event outcome over a follow-up period of at least three months.

Studies in which the intervention was delivered exclusively by pharmacists or physicians without meaningful nursing involvement, and studies reporting only knowledge or attitudinal outcomes without an accompanying adherence or clinical event measure, were excluded (Vrijens et al., 2012). Two reviewers independently screened titles, abstracts, and full texts, with disagreements resolved through discussion and, where necessary, consultation with a third reviewer. Methodological quality was appraised using the Mixed Methods Appraisal Tool (MMAT), which accommodates the inclusion of both experimental and observational designs within a single review. Given substantial variability in intervention format, adherence measurement instrument, and follow-up duration across included studies, a meta-analysis was not performed; results were synthesized narratively and summarized using medians and ranges.

Results

The database search identified 1,647 records after duplicate removal. Following title, abstract, and full-text screening, 18 studies met all inclusion criteria and were included in the final synthesis. As summarized in Table 1, included studies comprised eight randomized controlled trials, six quasi-experimental studies, and four prospective cohort studies, with a combined sample of 6,214 patients across all included reports. Sample sizes ranged from 64 to 1,382 participants, and follow-up periods ranged from three to eighteen months.

Fifteen of the 18 included studies (83.3%) reported a statistically significant improvement in medication adherence among patients receiving a nurse-delivered intervention relative to usual care. Adherence was most commonly measured using self-report instruments such as the Morisky Medication Adherence Scale, pharmacy refill or proportion of days covered calculations, or, in studies involving warfarin, the percentage of time spent within the therapeutic international normalized ratio range (TTR). Across the 14 studies reporting a comparable adherence percentage or proportion outcome, the median absolute increase in adherence associated with the nursing intervention was 15.4 percentage points, with individual study effects ranging from a non-significant 2-point increase to a 31-point increase.

Among the seven studies evaluating warfarin-treated patients using time in therapeutic range as an outcome, nurse-led intervention was associated with a median absolute increase in TTR of 11.3 percentage points, with the largest gains observed in programs incorporating structured, nurse-managed dose-adjustment protocols alongside patient education. Clinical event outcomes, including stroke, systemic embolism, and major bleeding, were reported in nine of the 18 studies. Pooling these outcomes narratively, nurse-delivered intervention was associated with a median relative reduction of 21.7% in composite anticoagulation-related adverse events over follow-up periods of six to eighteen months, although individual study estimates were imprecise given the relatively low absolute event rates and modest sample sizes typical of adherence-focused trials rather than dedicated outcome trials.

As summarized in Table 2, multicomponent interventions that combined structured baseline education with individualized coaching and sustained follow-up, most commonly delivered through scheduled telephone contact by a consistent nurse case manager, produced substantially larger effects on both adherence and clinical event outcomes than education delivered in isolation. Remote monitoring and telehealth-based interventions, including programs incorporating electronic pill reminders or smartphone-based adherence tracking reviewed periodically by nursing staff, produced intermediate effects, generally exceeding education-only programs but falling somewhat short of the largest multicomponent, in-person coaching models. Several studies noted that the relationship-continuity component, meaning contact with the same named nurse across follow-up encounters rather than a rotating care team, was independently associated with higher adherence, suggesting that the interpersonal and relational elements of nursing follow-up may be as important as the specific educational content delivered (Clarkesmith et al., 2013; Smet et al., 2018).

Quality appraisal using the MMAT indicated that the eight randomized controlled trials generally demonstrated adequate methodological rigor, with the most frequent limitation relating to the inability to blind participants or intervention delivery staff given the nature of a behavioral, nurse-delivered intervention. The six quasi-experimental studies and four prospective cohort studies were rated as having greater risk of bias, primarily due to non-equivalent comparison groups, reliance on self-reported adherence measures without an objective corroborating measure, and inconsistent adjustment for baseline adherence propensity or health literacy.

Discussion

This systematic review found that nurse-delivered interventions produce clinically meaningful improvements in anticoagulation adherence among patients with atrial fibrillation, with the strongest and most consistent effects observed for multicomponent programs combining structured education with sustained, individualized follow-up. This finding aligns with broader chronic disease adherence literature, in which single-exposure educational interventions typically produce smaller and less durable effects than programs incorporating ongoing behavioral reinforcement and relationship continuity (Kripalani et al., 2007). Anticoagulation adherence appears particularly sensitive to this pattern, likely reflecting the asymptomatic nature of AF for many patients between symptomatic episodes, which removes the day-to-day symptomatic feedback that reinforces adherence in more visibly symptomatic chronic conditions.

The observed improvement in time in therapeutic range among warfarin-treated participants carries particular clinical significance, given the well-established relationship between TTR and both thromboembolic and hemorrhagic risk. Nurse-managed dosing protocols, in which trained nursing staff adjust warfarin dosing according to a standardized algorithm under physician oversight, appeared to produce larger TTR improvements than education-focused interventions alone, suggesting that nursing involvement in the clinical management pathway itself, rather than solely in patient-facing education, may offer additional adherence and outcome benefit (Wang et al., 2019). For patients transitioning to DOAC therapy, where laboratory monitoring is no longer required, the review’s findings suggest that structured nursing follow-up may serve a comparable function to the monitoring visit itself, providing a scheduled touchpoint that would otherwise be absent from the DOAC care pathway.

The consistent finding that relationship continuity, meaning contact with a single, consistent nurse across the follow-up period, was independently associated with improved adherence has practical implications for anticoagulation service design. Many outpatient anticoagulation and cardiology clinics operate with rotating nursing coverage, which may inadvertently undermine adherence-focused efforts by preventing patients from developing the kind of sustained, trusted relationship that appeared to drive the largest effects in this review. Health systems seeking to implement or expand nurse-led anticoagulation adherence programs may therefore benefit from structuring services around a named case-manager model rather than a rotating-coverage model, even when total nursing full-time-equivalent staffing remains unchanged (Smet et al., 2018).

Several limitations of the underlying evidence base constrain the certainty of these conclusions. Adherence was measured using a wide range of instruments across included studies, including self-report scales, pharmacy refill data, and TTR, limiting direct comparability of effect sizes across studies and precluding meta-analysis. Self-reported adherence measures, used in the majority of included studies, are subject to social desirability bias and may overestimate true adherence relative to objective measures such as electronic pill-bottle monitoring, which was used in only two included studies. Clinical event outcomes, while directionally favorable, were derived from studies not powered specifically to detect differences in stroke, embolism, or bleeding rates, and should be interpreted as hypothesis-generating rather than definitive. Finally, intervention intensity and nursing training requirements varied considerably across included multicomponent programs, and the resource intensity required to replicate the largest observed effects, including dedicated case-manager staffing and sustained follow-up contact over six to eighteen months, was inconsistently reported, limiting conclusions about the cost-effectiveness or scalability of the most effective models (Franek, 2013).

Future research would benefit from standardized, objective adherence measurement, ideally incorporating electronic monitoring or linked pharmacy claims data, across future intervention trials to allow more direct comparison and eventual meta-analytic synthesis. Adequately powered trials examining hard clinical endpoints, including stroke, systemic embolism, and major bleeding, as primary rather than secondary outcomes would strengthen the evidence available to health systems considering investment in nurse-led adherence programs. Further investigation into the specific mechanism underlying the relationship-continuity effect, and into the minimum intervention intensity and duration required to sustain adherence gains beyond eighteen months, would also meaningfully advance this literature. Taken together, the findings of this review support the expansion of structured, multicomponent, nurse-led adherence interventions, delivered with an emphasis on relationship continuity, as an effective and comparatively low-resource strategy for improving anticoagulation adherence and reducing preventable stroke and bleeding events among patients with atrial fibrillation.

References

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