Table 1.

Risks of first hospital admission according to ICD9-CM classification after date of diagnosis in CD subjects compared to matched references^a

ICD codes	Disease category	REFERENCES (n = 5681)		CD (n = 1294)		HR (95 % CI)
		n	py	n	py
001–V89	Any	1245	33072	499	5915	2.34 (2.08–2.63)
001–139	Infectious and parasitic diseases	73	40900	44	9396	2.79 (1.89–4.12)
140–239	Neoplasms	56	41220	27	9686	1.89 (1.16–3.08)
240–279	Endocrine. metabolic. immunity dis.	96	40936	69	9328	3.19 (2.32–4.40)
280–289	Dis. of the blood and blood–forming organs	23	41334	25	9614	4.47 (2.49–8.01)
290–319	Mental disorders	60	41203	35	9618	2.52 (1.64–3.87)
320–389	Dis. of the nervous system and sense organs	114	40681	56	9414	2.14 (1.53–2.98)
390–459	Dis. of the circulatory system	29	41405	16	9766	2.77 (1.49–5.18)
460–519	Dis. of the respiratory system	347	38348	121	8763	1.59 (1.28–1.98)
520–579	Dis. of the digestive system	220	40228	232	7846	5.59 (4.57–6.83)
580–629	Dis. of the genito–urinary system	94	40861	42	9533	1.95 (1.32–2.86)
630–679	Complications of pregnancy and puerperium	46	41394	15	9807	1.48 (0.82–2.67)
680–709	Dis. of skin and subcutaneous tissue	55	41215	16	9722	1.22 (0.68–2.17)
710–739	Dis. of the muscoloskeletal tissue	104	41056	27	9716	0.88 (0.55–1.44)
740–779	Congenital anomalies/Perinatal conditions	90	40902	44	9482	2.18 (1.50–3.17)
780–799	Ill-defined conditions	83	40898	55	9413	2.94 (2.06–4.19)
800–999	Injuries and poisoning	167	41491	57	9840	1.35 (0.98–1.86)
V01–V89	Factors influencing health status	58	41092	41	9468	2.94 (1.94–4.47)

Py person-years, CD celiac disease, HR Hazard Ratio, CI confidence interval, Dis. Disease

Figures in bold are statistically significant results (p-value <0.05)

^aMatched by year of birth, gender and maternal education