Table 3. Proportions of reporting any problem in EQ-5D and EQ VAS among the four groups.

	Total	Groups					NHSS 2008 [23].
		Group 1	Group 2	Group 3	Group 4	P-value	Total	Western
EQ-5D
mobility	5.6	23	14.8	10.4	2.3	<0.0001	5.2	4.8
self-care	3.6	17.2	8.6	6.9	1.3	<0.0001	3.3	3
usual activities	5.3	23.9	13.1	10.5	2	<0.0001	4.8	4.4
pain and discomfort	8.8	40.9	19.3	21.3	3.3	<0.0001	9.2	7.4
anxiety and depression	7.6	29	15.5	12.8	4	<0.0001	6.4	5.8
EQ VAS
Mean(SE)	80(0.7)	65.3 (1.7)	71.6 (0.8)	76.7 (1.4)	82.7 (0.7)	<0.0001	79.8 (−)	77.6 (−)

Group 1: People with chronic conditions and had experienced discomfort during the two weeks immediately before the survey;

Group 2: People with chronic conditions but did not experience any discomfort during the two weeks immediately before the survey;

Group 3: People without chronic conditions and experienced discomfort during the two weeks immediately before the survey;

Group 4: People without chronic condition but did not experience any discomfort during the two weeks immediately before the survey.

P value: chi-square test whether there is any difference among any of the four groups.

NHSS 2008: National Health Service Survey conducted in 2008 in China. We recalculated the EQ-5D and EQ VAS of the overall population and western population according to the results reported by Sun S [23].