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.

Table 2 Prevalence of selected comorbidities at baseline in diabetic and control groups, 2000-2008, Taiwan, China

Variables1	Control group		Diabetic group		P value2
	n	%	n	%
Hypertension					< 0.001
No	235 138	38.2	81 913	13.3
Yes	379 733	61.8	533 619	86.7
Gout					< 0.001
No	471 346	76.7	416 400	67.6
Yes	143 525	23.3	199 132	32.4
Hyperlipidemia					< 0.001
No	382 560	62.2	163 598	26.6
Yes	232 311	37.8	451 934	73.4
Cystic fibrosis					0.006
No	614 836	99.9	615 470	99.9
Yes	35	0.1	62	0.1
Cirrhosis					< 0.001
No	589 838	95.9	569 024	92.4
Yes	25 033	4.1	46 508	7.6
Cholangitis					< 0.001
No	605 197	98.4	602 604	97.9
Yes	9674	1.6	12 928	2.1
Caroli’s disease					< 0.001
No	612 979	99.7	613 326	99.6
Yes	1892	0.3	2206	0.4
Crohn’s disease					< 0.001
No	590 912	96.1	590 404	95.9
Yes	23 959	3.9	25 128	4.1
Hemolytic anemia					< 0.001
No	612 100	99.6	612 111	99.4
Yes	2771	0.4	3421	0.6
Total	614 871	100.0	615 532	100.0

¹Hypertension (ICD-9: 401-405, A260, A269), gout (ICD-9: 274), hyperlipidemia (ICD-9: 272.0–272.4, A182), cystic fibrosis (ICD-9: 277.0), cirrhosis (ICD-9: 571.2, 571.5, 571.6), cholangitis (ICD-9: 575.8, 576.1), Caroli’s disease (ICD-9: 576.2), Crohn's disease (ICD-9: 555.0, 555.1, 555.9), hemolytic anemia (ICD-9: 282–283);

²Based on χ² test.

Table 3 Overall age- and sex-specific incidence densities and relative hazards of gallstone disease (ICD-9: 574) in diabetic and control groups, 2000-2008, Taiwan, China

Variables1	Control group				Diabetic group				aHR2 (95% CI)24 in association with diabetic group
	No. of patients	No. of events	ID2 (per 1000 patient-years) (95% CI)23		No. of patients	No. of events	ID2 (per 1000 patient-years) (95% CI)23
Men
< 45	40 537	1467	4.25 (4.24-4.25)		40 537	2360	7.06 (7.06-7.07)		0.80 (0.66-0.96)4
45-64	141 899	9184	7.59 (7.58-7.59)		141 899	12 561	11.23 (11.22-11.23)		1.03 (0.96-1.09)4
> 64	113 127	10 241	12.31 (12.30-12.31)		113 129	12 224	16.40 (16.39-16.40)		1.20 (1.14-1.27)4
Total	295 563	20 892	8.75 (8.75-8.76)		295 566	27 145	12.35 (12.34-12.35)		1.12 (1.07-1.16)5
Women				Increased % vs males				Increased % vs males
< 45	29 080	1292	5.11 (5.11-5.12)	+ 20.8%	29 079	1898	7.69 (7.69-7.70)	+ 8.9%	0.75 (0.60-0.94)4
45-64	154 911	12 596	9.30 (9.29-9.30)	+ 22.5%	154 911	15 989	12.59 (12.58-12.59)	+ 12.1%	0.96 (0.90-1.02)4
> 64	135 317	13 336	12.61 (12.60-12.61)	+ 20.8%	135 318	15 685	16.81 (16.81-16.82)	+ 2.5%	1.13 (1.07-1.18)4
Total	319 308	27 224	10.21 (10.21-10.22)	+ 2.4%	319 310	33 572	13.70 (13.70-13.71)	+ 10.9%	1.05 (1.01-1.08)5
Overall	614 871	48 116	9.52 (9.52-9.53)		615 532	60 734	13.06 (13.06-13.07)		1.08 (1.05-1.10)6

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

²ID: Incidence density; aHR: Adjusted hazard ratio;

³Based on poisson assumption;

⁴Based on Cox proportional hazard regression adjusted for all variables, except for age and sex;

⁵Based on Cox proportional hazard regression adjusted for all variables, except for sex;

⁶Based on Cox proportional hazards regression adjusted for age, sex, insurance premium, Charlson score, geographic area, urbanization status, and status of diabetes, hypertension, gout, hyperlipidemia, cystic fibrosis, cirrhosis, cholangitis, Caroli’s disease, Crohn's disease and hemolytic anemia.