Table 2

Incidence rates of ischaemic heart disease and acute myocardial infarction in patients with ankylosing spondylitis (AS) and controls

	Patients with AS			Controls			Incidence rate ratio†	95% CI
	Event	Person-years	Incidence rate*	Event	Person-years	Incidence rate*	Incidence rate ratio†	95% CI
Ischaemic heart disease‡	102	23 719	4.30	600	165 176	3.63	1.18	(0.96 to 1.46)
By gender
Male	76	16 495	4.61	497	115 956	4.29	1.07	(0.84 to 1.37)
Female	26	7224	3.60	103	49 219	2.09	1.72	(1.12 to 2.64)
By age (years)
16–39	3	7674	0.39	17	52 690	0.32	1.21	(0.36 to 4.13)
40–49	9	6367	1.41	74	43 523	1.70	0.83	(0.42 to 1.66)
50–59	27	4779	5.65	135	33 636	4.01	1.41	(0.93 to 2.13)
60–69	35	3081	11.36	180	21 435	8.40	1.35	(0.94 to 1.94)
70–79	20	1321	15.14	128	10 112	12.66	1.20	(0.75 to 1.92)
80+	8	495	16.16	66	3763	17.54	0.92	(0.44 to 1.92)
Acute myocardial infarction§	38	24 560	1.55	291	170 551	1.71	0.91	(0.65 to 1.27)
By gender
Male	31	17 053	1.82	248	120 175	2.06	0.88	(0.61 to 1.28)
Female	7	7507	0.93	43	50 375	0.85	1.09	(0.49 to 2.43)
By age category (years)
16–39	1	7683	0.13	9	52 823	0.17	0.76	(0.10 to 6.03)
40–49	4	6388	0.63	35	43 887	0.80	0.79	(0.28 to 2.21)
50–59	12	4921	2.44	59	34 680	1.70	1.43	(0.77 to 2.67)
60–69	9	3346	2.69	76	23 144	3.28	0.82	(0.41 to 1.63)
70–79	7	1594	4.39	68	11 601	5.86	0.75	(0.34 to 1.63)
80+	5	626	7.98	44	4399	10.00	0.80	(0.32 to 2.01)

Bold typeface indicates statistical significance (p<0.05). *Number of patients or controls with an event/1.000 person-years.
†The incidence rate ratio is calculated as the incidence rate for patients divided by the incidence rate of controls.
‡Because patients with a history of ischaemic heart disease before or at the index date were excluded, the total number of patients with AS was 3640 and the total number of controls was 25 299.
§Because patients with a history of acute myocardial infarction before or at the index date were excluded, the total number of patients with AS was 3738 and the total number of controls was 25 843.