A population-based cohort study of symptomatic gallstone disease in diabetic patients

Table 1 Characteristics of diabetic and control groups in this study, 2000-2008, Taiwan, China

Variables1	Control group		Diabetic group
	n	%	n	%
Age, yr
< 45	69 617	11.3	69 825	11.3
45-64	296 810	48.3	297 142	48.3
> 64	248 444	40.4	248 562	40.4
Mean age (± SD)	60.0 ± 12.8		60.1 ± 12.7
Sex
Female	319 308	51.9	319 310	51.9
Male	295 563	48.1	295 566	48.1
Insurance premium (NTD)2
Dependent	156 296	25.4	169 761	27.6
< Median (19 200)	135 948	22.1	137 408	22.3
≥ Median	322 627	52.5	308 363	50.1
Mean premium (± SD)3	20 142.6 ± 15 269.4		19 307.7 ± 14 454.7
Charlson score
0	551 094	89.6	0	0.0
1	49 777	8.1	444 658	72.2
≥ 2	14 000	2.3	170 874	27.8
Mean score (± SD)	0.1 ± 0.4		1.4 ± 0.8
Geographic area
Northern	269 239	44.2	269 920	44.4
Central	151 693	25.0	141 321	23.2
Southern	168 995	27.8	178 627	29.4
Eastern	17 938	3.0	17 944	3.0
Urbanization status
Metropolis	243 808	39.8	255 467	42.0
Satellite city/town	163 515	26.8	159 687	26.2
Rural area	202 343	33.2	193 949	31.8
Total	614 871	100.0	615 532	100.0

¹The inconsistencies between the total population and the sums of the populations for individual variables are due to missing information;

²NTD: New Taiwan Dollars;

³Dependent insurers were not included.