Table 2

Comparison of incidence and HR of DVT and PE between patients with and without rheumatoid arthritis, stratified by sex, age and the presence of comorbidity

Variables	Rheumatoid arthritis						IRR (95% CI)	Adjusted HR† (95% CI)
	No			Yes
	Event	PY	Rate‡	Event	PY	Rate‡
DVT	255	792 941	3.22	208	193 753	10.70	3.34 (3.22 to 3.46)***	3.36 (2.79 to 4.03)***
Sex
Female	191	618 905	3.09	167	152 011	11.0	3.56 (3.41 to 3.71)***	3.58 (2.90 to 4.40)***
Male	64	174 035	3.68	41	41 742	9.82	2.67 (2.47 to 2.89)***	2.74 (1.85 to 4.06)***
Stratified age
≤50	27	343 813	0.79	40	87 222	4.59	5.84 (5.48 to 6.22)***	5.55 (3.40 to 9.07)***
50–65	108	291 976	3.70	78	70 954	11.0	2.98 (2.80 to 3.16)***	2.83 (2.11 to 3.79)***
65+	120	157 152	7.64	90	35 577	25.3	3.31 (3.07 to 3.57)***	3.20 (2.43 to 4.21)***
Comorbidity§
No	173	714 076	0.24	143	167 162	0.86	3.53 (3.39 to 3.68)***	3.75 (3.00 to 4.68)***
Yes	82	78 865	1.04	65	26 591	2.44	2.35 (2.14 to 2.59)***	2.41 (1.74 to 3.34)***
PE	139	793 285	1.75	70	194 299	3.60	2.06 (1.97 to 2.14)***	2.07 (1.55 to 2.76)***
Sex
Female	108	619 154	1.74	58	152 463	3.80	2.18 (2.08 to 2.28)***	2.20 (1.60 to 3.03)***
Male	31	174 130	1.78	12	41 837	2.87	1.61 (1.47 to 1.77)***	1.61 (0.82 to 3.14)
Stratified age
≤50	10	343 840	0.29	9	87 374	1.03	3.54 (3.32 to 3.78)***	3.13 (1.26 to 7.77)*
50–65	47	292 117	1.61	26	71 165	3.65	2.27 (2.12 to 2.43)***	2.14 (1.32 to 3.46)**
65+	82	157 328	5.21	35	35 761	9.79	1.88 (1.73 to 2.04)***	1.79 (1.20 to 2.66)**
Comorbidity§
No	81	714 325	0.11	46	167 559	0.27	2.42 (2.32 to 2.53)***	2.58 (1.79 to 3.70)***
Yes	58	78 960	0.73	24	26 740	0.90	1.22 (1.10 to 1.36)***	1.37 (0.85 to 2.21)

*p<0.05, **p<0.01, ***p<0.001.
†Adjusted HR: multivariable analysis including age, sex and comorbidities.
‡Rate, incidence rate, per 10 000 person-years.
§Comorbidity: Patients with any one of comorbidities were classified as the comorbidity group.
DVT, deep vein thrombosis; IRR, incidence rate ratio; PE, pulmonary embolism.