Family history and disease outcomes in patients with Crohn’s disease: A comparison between China and the United States

Table 1 Demographics of Crohn’s disease patients in China and the United States recruited 2014-2016

	China (n = 49)	United States (n = 145)	P value
Age at clinical diagnosis (yr)	26.6 (13.1-46.7)	25.9 (5.1-73.1)	0.87
Age at survey completion (yr)	29.5 (19.2-49.9)	43.4 (18.3-82.7)	< 0.0001
Duration of disease at time of survey (yr)	2.2 (0.0-12.7)	12.4 (0.0-55.4)	< 0.0001
Calendar year of diagnosis	2013 (2003-2015)	2003 (1960-2015)	< 0.0001
Before 1969	0	1.4%
1970-1979	0	6.2%
1980-1989	0	9.7%
1990-1999	0	25.5%
2000-2009	12.2%	30.3%
2010-2015	87.8%	26.9%
Female (%)	42.9%	58.6%	0.06
Smoking status at diagnosis (%)			0.5
Current smoker	12.2%	16.5%1
Former smoker	6.1% (n = 3)	10.8%
Never smoker	81.6%	72.7%
Number of siblings	2 (0-7)	2 (0-9)	0.2
0	8.2% (n = 4)	6.9%
1	12.2%	29.7%
2	44.9%	30.3%
3	12.2%	18.6%
4+	22.5%	14.5%
Number of children	0 (0-3)	0 (0-7)	0.81
0	53.1%	51.0%
1	26.5%	15.9%
2	18.4%	22.8%
3	2.0% (n = 1)	9.0%
4+	0	1.3%

¹Six participants recruited in the United States did not report smoking status at diagnosis.

Table 2 Prevalence and odds ratio of having family history of inflammatory bowel disease in China vs the United States

	China(n = 49)	United States(n = 145)	Unadjusted OR (95%CI) P value (Reference = US)	Adjusted1 OR (95% CI) P value (Reference = US)
Any family history of IBD (%)	4.1% (n = 2)	39.3%	0.07 (0.02-0.28)	0.08 (0.02-0.34)
			P = 0.0002	P = 0.0008
First-degree family history of IBD (%)	4.1% (n = 2)	23.5%	0.14 (0.03-0.60)	0.14 (0.03-0.65)
			P = 0.008	P = 0.01

¹Adjusted for the total number of siblings and children, and duration of disease at survey completion. IBD: Inflammatory bowel disease; OR: Odds ratio.

Table 3 Prevalence and odds ratio of Crohn’s disease outcomes in China vs the United States

Outcome	China(n = 49)	United States(n = 145)	Unadjusted OR (95%CI), P value (Reference = US)	Adjusted1 OR (95%CI), P value (Reference = US)
Ileal involvement	63.3%	63.5%	0.99 (0.50-1.94)	1.14 (0.51-2.55)
			P = 0.98	P = 0.74
Surgery for IBD	51.0%	49.7%	1.06 (0.55-2.02)	1.70 (0.77-3.75)
			P = 0.87	P = 0.19
Ever steroids use	46.9%	91.0%	0.09 (0.04-0.19)	0.19 (0.07-0.50)
			P < 0.0001	P = 0.0007
Steroids use within 3 mo of diagnosis	24.5%	46.2%	0.38 (0.18-0.78)	0.53 (0.22-1.25)
			P = 0.009	P = 0.15
Ever immunomodulators2	73.5%	61.4%	1.74 (0.85-3.57)	2.13 (0.92-4.91)
	(n = 36)	(n = 89)	P = 0.13	P = 0.08
6-MP/Azathioprine	88.9%	89.9%
Methotrexate	19.4%	23.6%
Cyclosporine	0%	6.7%
Tacrolimus	0%	3.4%
Ever biologics use	34.7%	73.8%	0.19 (0.09-0.38)	0.09 (0.04-0.24)
			P < 0.0001	P < 0.0001
Ever TPN use	8.2%	21.4%	0.33 (0.11-0.98)	0.67 (0.19-2.38)
			P = 0.05	P = 0.54
Antibiotics use within 30 d before time of survey	18.8%	15.9%	1.22 (0.52-2.87)	1.29 (0.47-3.55)
			P = 0.64	P = 0.62

¹Adjusted for sex, smoking status at diagnosis, age at diagnosis older than 40 years or less, and duration of disease at survey completion;

²For ever users of immunomodulators, the percentage of use of each type of immunomodulators was calculated. IBD: Inflammatory bowel disease; 6-MP: Mercaptopurine; TPN: Total parenteral nutrition; OR: Odds ratio.