Table 2.

Incidence rate of recurrent venous thromboembolic events by risk factors

Risk factors	Clinical care pathway			Extended observation period
	Events frequency	Observation time patient‐years	Incidence rate (95% CI) per 100 patient‐years	Events frequency	Observation time patient‐years	Incidence rate (95% CI) per 100 patient‐years
Total	37	876	4.2 (3.1, 5.8)	64	2231	2.9 (2.2, 3.7)
Provoking risk factors (mutually exclusive groups)
Provoked by surgery	2	186	1.1 (0.3, 4.3)	6	475	1.3 (0.6, 2.8)
Non‐surgical transient risk factor	6	192	3.1 (1.4, 7.0)	11	519	2.1 (1.2, 3.8)
Unprovoked VTE	29	478	6.1 (4.2, 8.7)	47	1186	4.0 (3.0, 5.3)
Active cancer	0	21	N/A	0	52	N/A
Other risk factors
Male sex	26	429	6.1 (4.1, 8.9)	41	1042	3.9 (2.9, 5.3)
Female sex	11	447	2.5 (1.4, 4.4)	23	1190	1.9 (1.3, 2.9)
Pregnancy	0	11	N/A	1	30	3.3 (0.5, 23.7)
Contraceptive use at the time of thrombosis	0	94	N/A	1	270	0.4 (0.0, 2.6)
Travel	4	60	6.6 (2.5, 17.7)	8	175	4.6 (2.2, 3.7)
Immobilization	2	69	2.9 (0.7, 11.5)	2	168	1.2 (0.3, 4.8)
Inflammation	8	117	6.8 (0.3, 13.7)	15	317	4.7 (2.9, 7.9)
Previous VTE	2	175	1.1 (0.3, 4.6)	10	492	2.0 (1.1, 3.8)
Cardiovascular disease	10	209	4.8 (2.6, 8.9)	17	467	3.6 (2.3, 5.9)
Heart failure	0	12	N/A	1	33	3.0 (0.4, 21.6)
Known thrombophilia	0	36	N/A	1	91	1.1 (0.2, 7.8)
Venous insufficiency	0	59	N/A	0	106	N/A
Varicose veins	1	43	2.3 (0.3, 16.4)	3	139	2.2 (0.7, 6.7)
Smoking	7	200	3.5 (1.7, 7.4)	13	524	2.5 (1.4, 4.3)
Family history	10	260	3.9 (2.1, 7.2)	17	659	2.6 (1.6, 4.1)
Risk factors not assessed at baseline
Residual vein obstructiona	12	270	4.4 (2.5, 7.8)	22	689	3.2 (2.1, 4.8)
Elevated Villalta scoreb ,d	6	148	4.0 (1.8, 9.0)	14	362	3.9 (2.3, 6.5)
Elevated D‐dimerc	17	197	8.6 (5.4, 13.9)	26	514	5.1 (3.4, 7.4)
High factor VIIIc	9	120	7.5 (3.9, 14.5)	17	329	5.2 (3.2, 8.3)
Elevated CRPc	11	201	5.5 (3.0, 9.9)	22	537	4.1 (2.7, 6.2)

^aAssessed one week before intended cessation of anticoagulation treatment.

^bAssessed at six months.

^cAssessed one month after stopping OAC.

≥5 points.