Predictors of Adequate Ambulatory Anticoagulation among Adult Patients in a Tertiary Teaching and Referral Hospital in Kenya

David G Nyamu, Anastasia N Guantai, George O Osanjo, Ephraim Mwatha, Isaiah Gitonga, Mungania L Kanyiri


Background: Local anticoagulation services are inadequate and substantially underutilized despite compelling evidence showing that their appropriate use significantly reduces the risk of thromboembolic complications.

Objectives: To determine the predictors of adequate ambulatory anticoagulation services in Kenyatta National Hospital.

Methodology: A cross sectional study between December 2014 and April 2015 among 102 adult outpatients on anticoagulation using consecutive sampling was done. Information abstracted into a predesigned data collection tool included participants’ sociodemographic characteristics, regular sources of supply of anticoagulant, clinic pre-appointment reminders, indications of treatment and international normalized ratio tests. Data were analyzed using IBM Statistical Package for Social Sciences version 21.0 and logistic regression was used to determine independent predictors of adequate anticoagulation, which was defined as international normalized ratio ranging 2 - 3.

Results: Females were majority (76.5 %) and only 27.5 % of patients  had adequate anticoagulation control. The indication of warfarin for heart valve surgery (p=0.014) and deep venous thrombosis (p=0.021) were associated with adequate anticoagulation. Age above 60 years was associated with poor anticoagulation (p=0.006). Logistic regression revealed that the independent predictor of adequate anticoagulation was warfarin use due to heart valve surgery (OR=3.1; 95% CI: 1.2 – 7.9, p=0.017).

Conclusions: Ambulatory anticoagulation control in the hospital is poor. Further investigation is required to find out the reasons behind adequate anticoagulation in heart valve surgery patients.

Key Words: Ambulatory anticoagulation, anticoagulant, outpatient, international normalized ratio tests.


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