Table 2.

New study variables.

Variables	New value label
Eating	0 = no, can do; 1 = yes, cannot do
Dressing	0 = no, can do; 1 = yes, cannot do
Squatting	0 = no, can do; 1 = yes, cannot do
Lifting 5 kg	0 = no, can do; 1 = yes, cannot do
Stairs: 2-3 steps	0 = no, can do; 1 = yes, cannot do
Bus/boat alone	0 = no, can do; 1 = yes, cannot do
Age (years)	Continuous
Chronic disease	0 = no; 1 = presenting at least one of five chronic diseases (hypertension, diabetes, cancer, stroke, heart)
Education	0 = any education; 1 = no education
Female	0 = no; 1 = yes
Income	0 = adequacy; 1 = inadequacy
Living arrangement	0 = living alone; 1 = living with others
Marital status	0 = never married (reference)
	1 = married, living as couple
	2 = married, not living as couple
Working status	0 = working; 1 = not working
Rural	0 = no; 1 = yes
Bangkok	0 = no; 1 = yes
Central (excluding Bangkok)	0 = no; 1 = yes
North	0 = no; 1 = yes
Northeast	0 = no; 1 = yes
South	0 = no; 1 = yes (reference)
Year 2002	0 = no; 1 = yes (reference)
Year 2007	0 = no; 1 = yes
Year 2011	0 = no; 1 = yes