Chronic gastrointestinal symptoms and quality of life in the Korean population

Table 6 Multiple regression results: estimated coefficient of predictors of each SF-36 subscale domain

Variable	PF	RP	BP	GH	VT	SF	RE	MH
Female sex	-4.6	-9.6	-4.7	-5.3b	-4.3a	-3.6	-8.2	-1.8
Age1	-5.7c	-3.2	-1.3	-4.6b	-3.2a	-1.4	-1.2	-3.5b
Ever smoking	2.5	3	2	-2.6	2.3	2.4	3	1.3
Religion	4.1	9.7	-0.1	1.3	6.5a	-3.5	-3.5	2.3
< high school education	-6.7a	-5.8	-3	2.6	3.1	0.4	3.8	4.2
Low economic class	-2.8	-14.0a	-5.8	-3.3	-0.2	-3.9	-17.3	-0.2
Number of physician visit2	0.6	-4.8a	-4.8c	-4.1b	-1.9	-0.9	-4.8a	-3.5c
Presence of overlapping symptoms	-4.7	-3.5	-8.3a	-6.9	1.6	-3.9	-5.5	-8.3b
R2	0.375	0.134	0.165	0.19	0.09	0.09	0.124	0.177

PF: Physical function; RP: Role-physical; BP: Bodily pain; GH: General health; VT: Vitality; SF: Social function; RE: Role-emotion; MH: Mental health.

¹Age variables are categorized by 10 yr intervals;

²Number of physician visits for gastrointestinal symptoms: 0/yr(0), 1-2/yr(1), 3-5/yr(2), 6-10/yr(3), > 10/yr(4).

^aP < 0.05;

^bP < 0.01;

^cP < 0.001.