TITLE:
CoaguCarnet®: A Structured Paper Booklet to Improve Vitamin K Antagonist Monitoring—Protocol for an Ambispective Comparative Cohort Study in Côte d’Ivoire
AUTHORS:
Bénédicte Carine Boka, Patrick Coffie, Kouadio Arnaud Ekou, Laurent Désiré Flainde, Augustin Yeo, Marie-Laure Hauhouot, Serge Oga
KEYWORDS:
Vitamin K Antagonists, Anticoagulation, Patient-Held Records, Historical Cohort, Côte d’Ivoire
JOURNAL NAME:
World Journal of Cardiovascular Diseases,
Vol.16 No.10,
October
22,
2026
ABSTRACT: Background: Vitamin K antagonist (VKA) therapy requires reliable documentation of international normalised ratio (INR) measurements, prescribed doses, clinical decisions and next review. At the SSRCV, a conventional folded monitoring sheet has limited longitudinal space. A locally developed 31-page paper booklet, CoaguCarnet®, aims to improve the traceability of monitoring and facilitate continuity of care. Methods: This single-centre, non-randomised, ambispective comparative cohort study will identify exhaustively eligible historical patients with an index INR follow-up encounter between 1 January and 31 March 2026 and reconstruct individual six-month observation from the index date, ending no later than 30 September 2026. All eligible historical patients will be retained; the prospective CoaguCarnet® cohort will target 75 consecutively recruited patients from 15 October 2026, subject to operational authorisation, with six-month individual follow-up. This target is feasibility-based, not yet supported by a formal power calculation. The primary outcome is the patient-level mean five-item Clinical Traceability Index (CTI; 0 - 5), based strictly on the original monitoring support. Source retrieval, a common-item score, temporal changes, baseline differences and missingness will be analysed explicitly. We will also assess whether patients’ INR monitoring history can be reliably reconstructed and whether the available INR results are sufficient to calculate time in therapeutic range (TTR). In the CoaguCarnet® group, we will explore patients’ understanding of their anticoagulant treatment, their experience using the booklet, and their satisfaction with it. Discussion: This study will assess whether CoaguCarnet® improves the quality of anticoagulation records. It is not designed to determine whether the booklet reduces bleeding or thrombotic events. Because the two groups will be drawn from different periods, differences in patient characteristics and documentation practices may influence the findings, even after statistical adjustment. Results will therefore be interpreted as associations.