SNAP AF-52: Dose Appropriateness and Adherence to Oral Anticoagulation in Adults ≥65 With Atrial Fibrillation in Primary Care (Ordu, Türkiye)

NCT07242326 | Enrolling By Invitation

• 2 other identifiers: KAHSED-002pending
• Study Type: observational
• Target: 1,000
• Locations: 1 country
• Sites: 1

Brief Summary

SNAP AF-52 is an ambidirectional observational registry conducted in family health centers (primary care) across Ordu, Türkiye, enrolling adults ≥65 years with a pre-existing diagnosis of atrial fibrillation. The study assesses (a) label-concordant dosing of oral anticoagulants (DOACs/warfarin) using drug-specific criteria, and (b) medication adherence via Proportion of Days Covered (PDC) over the prior 12 months (good adherence defined as PDC ≥80%). Unsafe findings (e.g., suspected under-/overdosing, critical drug-drug interactions, very low renal function) trigger same-day referral to tertiary cardiology for evaluation and management. The retrospective window is Dec 1, 2024-Nov 30, 2025; the prospective single-visit inclusion window is Dec 1, 2025-May 31, 2026. No experimental treatment is administered; all care is routine.

Conditions

Medication Adherence; Atrial Fibrillation (AF); Direct Oral Anticoagulants (DOACs)

Keywords

DOAC;; apixaban; rivaroxaban; dabigatran; edoxaban; dose appropriateness; label-concordant dosing; Proportion of Days Covered (PDC); primary nonadherence; ISTH major bleeding; primary care

Outcome Measures

Primary Outcomes (2)

• Primary Outcome 1: Label-Concordant Dose Proportion

  Proportion of patients on label-concordant dose vs underdose vs overdose, by anticoagulant. Criteria include: Apixaban: 5 mg BID (standard) or 2.5 mg BID if ≥2 of: age ≥80 years, weight ≤60 kg, serum creatinine ≥1.5 mg/dL. Rivaroxaban: 20 mg QD if CrCl ≥50 mL/min; 15 mg QD if CrCl 15-49; avoid/evaluate if CrCl \<15. Dabigatran: 150 mg BID (standard); 110 mg BID considered if age ≥80 or if CrCl 30-50 and P-gp inhibitor; avoid/evaluate if CrCl \<30. Edoxaban: 60 mg QD (standard); 30 mg QD if CrCl 15-50, weight ≤60 kg, or specific P-gp inhibitors (e.g., dronedarone, verapamil, erythromycin, ketoconazole, cyclosporine); consider reduced efficacy if CrCl \>95.

  At index visit (assessed using baseline variables and the most recent renal function).

• Primary Outcome 2: Good Adherence (PDC ≥80%)

  Proportion of Days Covered (PDC) = (covered days / 365), with early refill carry-over and single-day duplicate fills not double-counted. Good adherence: PDC ≥80% (class-level and drug-specific PDC reported).

  Prior 12 months relative to index date

Secondary Outcomes (4)

• Secondary Outcome 1: Primary Nonadherence

  From first prescription within the 12-month

• Secondary Outcome 2: Ischemic Events

  Prior 12 months.

• Secondary Outcome 3: Hemorrhagic Events

  Prior 12 months

• Secondary Outcome 4: Same-Day Tertiary Referral Rate

  At index visit

Study Arms (1)

Retrospective Records Cohort

Adults aged ≥65 years with atrial fibrillation and any oral anticoagulant use documented within Dec 1, 2024-Nov 30, 2025. Data are abstracted from existing records to determine dose appropriateness at the index regimen and 12-month PDC, and to capture ischemic (I63/G45/I74) and hemorrhagic (I60-I62; ISTH major) events. No patient contact and no protocol-assigned treatment.

Eligibility Criteria

• Age: 65 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Adults aged ≥65 years with established atrial fibrillation (any type) receiving care in family health centers across Ordu, Türkiye. The prospective cohort enrolls consecutive eligible attendees during Dec 1, 2025-May 31, 2026 at a single routine visit; the retrospective cohort includes patients with AF who received an oral anticoagulant during Dec 15, 2025-May 31, 2026 identified from primary care records. Exclusions: mechanical prosthetic heart valve or moderate-severe rheumatic mitral stenosis, and cases lacking the minimal data needed for dose/adherence classification. No investigational treatment is delivered; care is routine with same-day tertiary referral when unsafe dosing, high-risk drug interactions, or very low renal function are detected.

You may qualify if:

• Age ≥65 years.
• Established atrial fibrillation (any type) documented in the medical record.
• Presenting to a family health center (primary care) in Ordu province during the prospective window or having records within the retrospective window.
• On an oral anticoagulant (DOAC) at any time in the 12-month window.

You may not qualify if:

• Mechanical prosthetic heart valve or moderate-to-severe rheumatic mitral stenosis
• Participation in an interventional drug study affecting anticoagulation
• Lack of minimal data elements required for dose classification (age, sex, body weight, serum creatinine with date, current OAC and regimen)
• Investigator judgment that reliable data cannot be obtained from records

Sponsors & Collaborators

• Kotyora Family Medicine Health Management and Education Association: lead
• Ordu University Faculty of Medicine, Department of Cardiology: collaborator

Study Sites (1)

Ordu University Faculty of Medicine, Department of Cardiology

Ordu, Ordu, 52200, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Medication Adherence; Atrial Fibrillation

Condition Hierarchy (Ancestors)

Patient Compliance; Patient Acceptance of Health Care; Treatment Adherence and Compliance; Health Behavior; Behavior; Arrhythmias, Cardiac; Heart Diseases; Cardiovascular Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Seçkin Dereli, MD, Assoc. Prof.

  Ordu University Faculty of Medicine, Department of Cardiology (Turkey)

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: NETWORK
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 17, 2025
• First Posted: November 21, 2025
• Study Start: December 15, 2025
• Primary Completion (Estimated): December 30, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: February 25, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)