Assessment of Knowledge of Anticoagulation Therapy (Warfarin) And INR Control Among Outpatients in A Tertiary Hospital in Lagos, Nigeria
Keywords:
Warfarin knowledge, anticoagulation, INR controlAbstract
Method: The study was a consecutive cross-sectional survey. Patients (n= 70) on warfarin and visiting outpatient clinic of the cardiology unit from July 2016- September 2016 were recruited upon their consent and asked to complete the AKA questionnaire. Demographic and clinical data were manually extracted from patients' record data. Passing score was defined as at least 12 correct responses out of 23- INR relevant AKA questions (52%). INR control was defined by 3 outcome measures: number of INRs within goal range, time in therapeutic range (TTR), and standard deviation (SD) of INR values.
Result: Seventy patients enrolled for this study and 85.7% (n= 60) of the recruited patients consented to participate (females 45%; mean age+ SD 60.07+7.75; % with post-secondary education 28.3%). Most patients (n=52) had goal INR ranges of 2.0 to 3.0 (86.6%). Forty-five percent (n= 27) of participants had adequate knowledge of warfarin. There was no significant relationship between number of correct INR-relevant responses and INR control as defined by any of the 3 measures (count of INR values within range rho= 0.070, P= 0.595;TTR rho= 0.092, P= 0.595; and SD rho= 0.118, P=0.371).
Conclusion: Less than half of the participants had adequate knowledge of warfarin use and there was no significant relationship between patient warfarin knowledge and INR control. However, a more robust multiple centred survey is recommended before generalizability of outcomes.
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