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

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].