Table 1.

Characteristics of all households enrolled in the study

Characteristics	2003 (n=180)		2008 (n=2326)		2013 (n=4469)
	n	%	n	%	n	%
Household characteristics
Number of household members
<5	128	71.11	1916	82.37	3971	88.86
≥5	52	28.89	410	17.63	498	11.14
One or more members older than 60 years
No	104	57.78	1267	54.47	2003	44.82
Yes	76	42.22	1059	45.53	2466	55.18
One or more members younger than 5 years
No	148	82.22	1948	83.75	3806	85.16
Yes	32	17.78	378	16.25	663	14.84
Time spent travelling to the nearest medical centre
≤15 min	145	80.56	1701	73.13	3532	79.03
>15 min	35	19.44	625	26.87	937	20.97
Number of observations in each region
East	113	62.78	626	26.91	991	22.17
Centre	14	7.78	759	32.63	1670	37.37
West	53	29.44	941	40.46	1808	40.46
Annual household income*
Q1	2643.33	1265.69	3956.52	1680.38	4785.49	2590.40
Q2	6914.23	1353.25	9062.74	1247.41	13 003.64	2841.22
Q3	13 505	2716.15	14 699.42	2065.84	25 958.15	5174.25
Q4	29 194.35	10 927.31	31 665.48	20 295.22	61 082.23	44 409.99
Householders’ characteristics
Gender
Male	131	72.78	1796	77.21	3373	75.48
Female	49	27.22	530	22.79	1096	24.52
Age
<60	120	66.67	1442	61.99	2262	50.62
≥60	60	33.33	884	38.01	2207	49.38
Marital status
Unmarried	4	2.22	47	2.02	72	1.61
Married	155	86.11	1953	83.96	3735	83.58
Divorced	0	0	29	1.25	612	13.69
Widow or others	21	11.67	297	12.77	50	1.12
Education
Illiterate	52	28.89	511	21.98	811	18.15
Elementary school	71	39.44	917	39.44	1863	41.69
Junior high school	48	26.67	722	31.05	1418	31.73
Senior high school or above	9	5.00	175	7.53	377	8.44
Employment
Employed	126	70.00	1817	78.12	3222	72.10
Retired	12	6.67	60	2.58	157	3.51
Others	42	23.33	449	19.30	1090	24.39

*Annual household income of each year was divided into four levels according to the quartile, and the mean and SD of each level were calculated.