Estimating the prevalence of comorbid conditions and their effect on health care costs in patients with diabetes mellitus in Switzerland

Figures & data

Table 1 Population characteristics and prevalence of comorbidities among patients with, compared with patients without, diabetes

Population characteristics	Diabetes sample (n=50,751)			Nondiabetes sample (n=881,861)
	18–64 years, %	>64 years, %	P-value	18–64 years, %	>64 years, %	P-value
Total	37.8	62.2		74.3	25.7
Sex			<0.001†			<0.001†
Male	59.1	51.4		49.7	39.6
Female	40.9	48.6		50.3	60.4
Mean number of chronic conditions (standard deviation)	3.3 (2.0)	4.1 (1.9)	<0.001‡	1.2 (1.6)	3.0 (2.1)	<0.001‡
Comorbidities ¶
Hyperacidity-related disorders	34.9***	39.4***	<0.001†	14.4	30.8	<0.001†
Bone diseases (osteoporosis)	1.4***	4.2***	<0.001†	0.7	7.0	<0.001†
Cancer	1.7***	3.1	<0.001†	0.8	2.9	<0.001†
Cardiovascular diseases (including hypertension)	67.1***	91.0***	<0.001†	13.2	62.8	<0.001†
Dementia	1.4***	5.1	<0.001†	0.5	5.0	<0.001†
Epilepsy	6.5***	6.6***	0.467†	2.2	4.2	<0.001†
Glaucoma	3.9***	13.1***	<0.001†	0.9	10.2	<0.001†
Gout, hyperuricemia	4.4***	9.3***	<0.001†	0.6	3.7	<0.001†
HIV	0.3	0.1	<0.001†	0.3	0.01	<0.001†
Hyperlipidemia	43.8***	53.4***	<0.001†	4.8	25.7	<0.001†
Intestinal inflammatory diseases	0.6***	0.7	0.773†	0.4	0.7	<0.001†
Iron deficiency anemia	5.7***	6.4***	<0.001†	4.1	3.4	<0.001†
Migraine	1.2*	0.3***	<0.001†	1.5	0.6	<0.001†
Pain	45.3***	49.8***	<0.001†	22.6	39.0	<0.001†
Parkinson’s disease	1.4***	3.7***	<0.001†	0.4	3.0	<0.001†
Psychological disorders (sleep disorder, depression)	32.3***	41.0***	<0.001†	15.0	35.4	<0.001†
Psychoses	6.1***	6.3***	0.505†	2.4	4.9	<0.001†
Respiratory illness (asthma, chronic obstructive pulmonary disease)	11.8***	13.1***	<0.001†	5.9	10.5	<0.001†
Rheumatologic conditions	54.3***	55.0***	0.107†	30.8	47.1	<0.001†
Thyroid disorders	7.2***	9.3***	<0.001†	2.3	7.0	<0.001†
Tuberculosis	0.2***	0.1	0.026†	0.1	0.1	<0.001†

Notes:

† Chi-square test comparing age groups within each sample with/without diabetes;

‡ Wilcoxon test comparing age groups in sample with/without diabetes.

¶ Chi-square test comparing sample of same age groups across sample with diabetes and without diabetes, respectively;

* P-value, ≤0.05;

*** P-value, ≤0.001.

Table 2 Patient characteristics by comorbidity status among patients with and without diabetes

	Diabetes only		Diabetes + one comorbidity		Diabetes + two comorbidities		Diabetes + more than two comorbidities		Nondiabetes		Nondiabetes + one chronic condition		Nondiabetes + two chronic conditions		Nondiabetes + more than two chronic conditions
	N (%)	P-value*	N (%)	P-value*	N (%)	P-value*	N (%)	P-value*	N (%)	P-value*	N (%)	P-value*	N (%)	P-value*	N (%)	P-value*
Total	1,796 (3.5)		4,375 (8.6)		7,898 (15.6)		36,682 (72.3)		351,541 (39.9)		145,902 (16.5)		125,288 (14.2)		259,130 (29.4)
Sex		<0.001		<0.001		<0.001		<0.001		<0.001		<0.001		<0.001		<0.001
Male	1,212 (67.5)		2,733 (62.5)		4,909 (62.2)		18,710 (51.0)		197,128 (56.1)		67,160 (46.0)		55,337 (44.2)		95,922 (37.0)
Female	584 (32.5)		1,642 (37.5)		2,989 (37.9)		17,972 (49.0)		154,413 (43.9)		78,742 (54.0)		69,951 (55.8)		163,208 (63.0)
Age groups		<0.001		<0.001		<0.001		<0.001		<0.001		<0.001		<0.001		0.632
18–64 years	1,349 (75.1)		2,382 (54.4)		3,521 (44.6)		11,938 (32.5)		316,822 (90.1)		119,419 (81.9)		89,792 (71.7)		129,443 (50.0)
>64 years	477 (24.9)		1,993 (45.5)		4,377 (55.4)		24,744 (67.5)		34,719 (9.9)		26,483 (18.2)		35,496 (28.3)		129,687 (50.0)

Notes:

* Men compared with women, respectively, persons aged 18–64 years compared with persons younger than 64 years within the given disease group.

Table 3 Health care costs by comorbidity status among patients with and without diabetes

Health care costs, US$*	Diabetes only		Diabetes + one comorbidity		Diabetes + two comorbidities		Diabetes + more than two comorbidities		Nondiabetes		Nondiabetes + one chronic condition		Nondiabetes + two chronic conditions		Nondiabetes + more than two chronic conditions
	Mean; median	P-value	Mean; median	P-value*	Mean; median	P-value*	Mean; median	P-value*	Mean; median	P-value*	Mean; median	P-value†	Mean; median	P-value†	Mean; median	P-value†
Total health care	3,203; 1,944	–	4,275; 2,526	<0.001	5,579; 3,390	<0.001	14,223; 8,125	<0.001	928; 0	–	2,391; 1,032	<0.001	4,025; 2,012	<0.001	10,429; 5,434	<0.001
Outpatient care (total)	1,403; 913	–	1,956; 1,305	<0.001	2,537; 1,764	<0.001	5,577; 3,642	<0.001	322; 0	–	1,262; 677	<0.001	1,995; 1,238	<0.001	4,535; 2,793	<0.001
Primary care	497; 271	–	875; 569	<0.001	1,119; 755	<0.001	1,901; 1,255	<0.001	68; 0	–	331; 195	<0.001	553; 372	<0.001	1,219; 812	<0.001
Speciality care	525; 151	–	609; 187	<0.001	763; 271	<0.001	1,568; 697	<0.001	157; 0	–	535; 163	<0.001	772; 299	<0.001	1,508; 708	<0.001
Hospital ambulatory care	381; 0	–	473; 0	0.012	655; 0	<0.001	2,109; 384	<0.001	97; 0	–	396; 0	<0.001	669; 0	<0.001	1,810; 350	<0.001
Inpatient care	553; 0	–	826; 0	<0.001	1,271; 0	<0.001	4,764; 0	<0.001	479; 0	–	558; 0	<0.001	1,069; 0	<0.001	3,488; 0	<0.001
Prescription drug	857; 576	–	1,298; 933	<0.001	1,795; 1,408	<0.001	3,726; 2,655	<0.001	68; 0	–	524; 168	<0.001	922; 410	<0.001	2,482; 1,310	<0.001
Laboratory	222; 160	–	272; 204	<0.001	309; 232	<0.001	528; 352	<0.001	53; 0	–	164; 59	<0.001	231; 125	<0.001	406; 235	<0.001

Notes:

* Compared with the reference group “Diabetes-only;”

† compared with the reference group “Nondiabetes.”

Figure 1 Mean total health care costs in patients with and without diabetes by comorbidity status.

Table 4 Effect of (comorbid) conditions on health care costs among patients with and without diabetes

Health care costs†	Diabetes + one comorbidity‡		Diabetes + two comorbidities‡		Diabetes + more than two comorbidities‡		Nondiabetes + one chronic condition¶		Nondiabetes + two chronic conditions¶		Nondiabetes + more than two chronic conditions¶
	Coefficient, US$	95% confidence interval	Coefficient, US$	95% confidence interval	Coefficient, US$	95% confidence interval	Coefficient, US$	95% confidence interval	Coefficient, US$	95% confidence interval	Coefficient, US$	95% confidence interval
Total health care costs	1,096***	910–1,280	2,406***	2,222–2,586	10,584***	10,329–10,834	1,439***	1,408–1,469	2,805***	2,748–2,863	8,293***	8,199–8,389
Outpatient care costs (total)	587***	484–689	1,216***	1,120–1,310	4,314***	4,222–4,403	890***	872–908	1,606***	1,576–1,637	4,096***	4,058–4,137
Primary care costs	315***	251–378	509***	444–574	1,203***	1,140–1,265	248***	241–253	458***	448–469	1,103***	1,091–1,118
Speciality care costs	150***	74–221	329***	259–394	1,161***	1,103–1,214	345***	336–356	580***	563–596	1,298***	1,280–1,317
Hospital ambulatory care costs	128**	13–232	348***	251–436	1,795***	1,714–1,876	288***	276–301	558***	537–579	1,680***	1,651–1,709
Inpatient care costs	70***	68–72	398***	397–399	2,749***	2,747–2,750	228***	196–263	579***	519–645	1,927***	1,835–2,024
Prescription drug costs	551***	502–600	1,059***	1,013–1,106	3,066***	3,023–3,109	452***	443–460	846***	829–861	2,396***	2,373–2,419
Laboratory costs	64***	47–79	109***	95–122	344***	333–355	102***	100–106	169***	165–174	343***	339–348

Notes:

† Controlled for age and sex;

‡ patients with diabetes and without comorbidity as reference group;

¶ patients without diabetes and without any other disease as reference group.

** P-value, ≤0.01;

*** P-value, ≤0.001.

Table 5 Effect of the most frequent potential diabetes and nondiabetes-related comorbidities on health care costs among patients with diabetes

Health care costs†	Diabetes + cardiovascular diseases‡		Diabetes + rheumatologic conditions‡		Diabetes + hyperlipidemia ‡		Diabetes + pain‡		Diabetes + psychological disorders‡
	Coefficient, US$	95% confidence interval	Coefficient, US$	95% confidence interval	Coefficient, US$	95% confidence interval	Coefficient, US$	95% confidence interval	Coefficient, US$	95% confidence interval
Total health care costs	4,788***	4,576–5,000	2,815***	2,624–3,007	2,163***	1,964–2,362	8,324***	8,117–8,533	7,778***	7,538–8,022
Outpatient care costs (total)	1,814***	1,720–1,906	1,465***	1,383–1,548	1,046***	960–1,133	2,925***	2,838–3,013	2,432***	2,334–2,532
Inpatient care costs	1,507***	1,506–1,508	546***	545–547	217***	216–218	3,386***	2,974–3,828	3,352***	3,350–3,353
Prescription drug costs	1,377***	1,328–1,426	917***	875–967	976***	928–1,024	1,543***	1,496–1,592	1,542***	1,487–1,597
Laboratory costs	119***	109–130	123***	116–132	84***	75–92	207***	198–217	158***	149–168

Notes:

† Controlled for age and sex;

‡ patients with diabetes and without the given comorbidity as reference group.

*** P-value, ≤0.001.

Table 6 Effect of the most frequent potential diabetes and nondiabetes-related comorbidities on health care costs among patients with diabetes

Health care costs†	Diabetes + hyperacidity related disorders ‡		Diabetes + respiratory illness‡		Diabetes + glaucoma ‡		Diabetes + thyroid disorders‡		Diabetes + gout, hyperuricemia‡
	Coefficient, US$	95% confidence interval	Coefficient, US$	95% confidence interval	Coefficient, US$	95% confidence interval	Coefficient, US$	95% confidence interval	Coefficient, US$	95% confidence interval
Total health care costs	8,753***	8,512–8,998	5,540***	5,139–5,953	2,692***	2,278–3,120	2,883***	2,452–3,331	2,056***	1,618–2,510
Outpatient care costs (total)	3,060***	2,960–3,163	1,909***	1,744–2,077	1,956***	1,763–2,155	868***	694–1,047	1,035***	844–1,234
Inpatient care costs	3,625***	3,623–3,626	1,839***	1,838–1,841	91***	89–94	925***	923–927	271***	265–270
Prescription drug costs	1,921***	1,866–1,976	1,569***	1,473–1,669	6,601***	567–757	732***	630–835	825***	716–938
Laboratory costs	257***	248–268	153***	136–169	19*	4–34	158***	139–179	177***	155–199

Notes:

† Controlled for age and sex;

‡ patients with diabetes and without the given comorbidity as reference group.

* P-value, ≤0.05;

*** P-value, ≤0.001.