Predictive factors for obtaining a correct therapeutic range using antivitamin K anticoagulants: a tertiary center experience of patient adherence to anticoagulant therapy

Figures & data

Table 1 Patients’ characteristics

Variable
Patients (n)	68
Age (years)	62.6±13.1
Male sex (n, %)	30 (44)
Living environment
Rural	27%
Urban	73%
Education level
Secondary school	30%
High school	36%
University degree	34%
Indication for OACT
AF	62%
Mechanical valve prosthesis	9%
Venous thromboembolic disease	9%
Stroke	6%
CAD	4%
Others	10%
Duration of OACT (months)	44.5±50.3
Association of antiplatelet therapy (n, %)	25 (37)
AF scores*
CHAD2S2-VASC (embolic risk)	3.1±1.5
HAS-BLED (bleeding risk)	1.8±1.2

Note:

* AF scores were calculated only for the 42 patients with AF.

Abbreviations: AF, atrial fibrillation; CAD, coronary artery disease; OACT, oral anticoagulant therapy.

Table 2 Oral anticoagulation treatment-related characteristics

Question	Percentage
Who prescribed OACT?
Cardiologist	69
Internal medicine	11
Neurologist	6
General practitioner	14
Where was OACT first prescribed?
Hospital	86
General practitioner office	14
Have been informed about the benefits?
Yes	86
No	14
Have been informed about the risks?
Yes	81
No	19
Self-administration (versus help from someone else)	91
Follow the daily medication plan	91
Do not know the target INR range	37
Do not know the emergency INR value	52
Do not know the total duration of the treatment	27

Abbreviations: INR, international normalized ratio; OACT, Oral anticoagulant therapy.

Table 3 Predictive factors for obtaining a correct therapeutic range during OACT

Variable	Group A Appropriate INR (n=32)	Group B Inappropriate INR (n=36)	P-value
Age (years)	62.5±12.0	62.7±14.0	0.21
Male sex (n, %)	14	18	0.43
Living environment – rural (n, %)	22	27	0.50
Education level – higher education (n, %)	27	20	0.007
Compliance to daily dosage (n, %)	29	34	0.73
Explained benefits (n, %)	28	30	0.40
Explained risks (n, %)	25	28	0.77
Presence of mechanical valve prosthesis (n, %)	6	0	0.007
Associated antiplatelet therapy (n, %)	8	17	0.06
Duration of OACT (months)	62±72	36±35	0.06
CHA2DS2-VASC risk score	3.19±1.42	3.12±1.59	0.72
HAS-BlED risk score	1.94±1.28	1.68±1.21	0.83

Note: Lines with bold characters mark the significant determinants of appropriate INR.

Abbreviations: INR, international normalized ratio; OACT, oral anticoagulant therapy.

Table 4 Correlates of bleeding during oral anticoagulant therapy

History of bleeding	INR on admission			Other antithrombotic drugs
	<2	2–3	>3	No	Yes
Yes	8	10	0	10	7
No	19	23	8	33	18

Abbreviation: INR, international normalized ratio.