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.