Table 4

Effects of RA on the risks of DVT and PE, during various follow-up periods

	non-RA Cohort			RA Cohort
Follow-up time	Event	PY	Rate†	Event	PY	Rate†	IRR (95% CI)	Adjusted HR‡ (95% CI)
DVT (year)
≥1	223	792 014	2.82	172	193 456	8.89	3.16 (3.04 to 3.28)**	3.23 (2.65 to 3.94)**
≥2	200	789 210	2.53	135	192 589	7.01	2.77 (2.66 to 2.87)**	2.85 (2.29 to 3.55)**
≥3	165	758 473	2.18	115	184 700	6.23	2.86 (2.75 to 2.98)**	2.97 (2.34 to 3.77)**
≥4	140	717 121	1.95	84	174 235	4.82	2.47 (2.37 to 2.58)**	2.61 (1.99 to 3.42)**
≥5	113	663 769	1.70	66	160 691	4.11	2.41 (2.30 to 2.53)**	2.56 (1.89 to 3.48)**
≥6	80	600 307	1.33	51	144 423	3.53	2.65 (2.52 to 2.79)**	2.83 (1.99 to 4.02)**
PE (year)
≥1	127	792 368	1.60	64	194 008	3.30	2.06 (1.97 to 2.15)**	2.07 (1.53 to 2.80)**
≥2	107	789 561	1.36	53	193 180	2.74	2.02 (1.94 to 2.11)**	2.07 (1.49 to 2.88)**
≥3	86	758 839	1.13	40	185 289	2.16	1.90 (1.82 to 1.99)**	1.98 (1.36 to 2.89)**
≥4	66	717 492	0.92	34	174 850	1.94	2.11 (2.02 to 2.22)**	2.21 (1.46 to 3.35)**
≥5	49	664 168	0.74	24	161 307	1.49	2.02 (1.92 to 2.12)**	2.14 (1.31 to 3.49)*
≥6	34	600 776	0.57	18	145 034	1.24	2.19 (2.07 to 2.32)**	2.39 (1.34 to 4.23)*

*p<0.01, **p<0.001.
†Rate, incidence rate, per 10 000 person-years; .
‡Adjusted HR: multivariable analysis including age, sex and comorbidities.
DVT, deep vein thrombosis; PE, pulmonary embolism; IRR, incidence rate ratio; RA, rheumatoid arthritis.