Cardiovascular disease-related chronic conditions among Veterans Affairs nonmetastatic colorectal cancer survivors: a matched case–control analysis

Figures & data

Figure 1 Patient flow diagram.

Table 1 Demographic characteristics of patient sample

	CRC survivors (n=9,758)		Noncancer controls (n=29,066)
	No.	%	No.	%
Sex
Male	9,530	97.7	28,440	97.8
Female	228	2.3	626	2.2
Race
White	7,738	79.3	23,136	79.6
Minority	1,945	19.9	5,712	19.7
Marital status
Married	4,769	48.9	16,219	55.8
Not married	4,946	50.7	12,649	43.5
Copay status
Free – disability	3,379	34.6	10,086	34.7
Free – low-income	4,320	44.3	12,856	44.2
Must pay	1,529	15.7	4,549	15.7
Region
Midwest	2,089	21.4	6,232	21.4
Northeast	1,502	15.4	4,453	15.3
Southeast	3,931	40.3	11,740	40.4
West	2,236	22.9	6,641	22.8
Body mass index
Underweight & healthy weight (<18.5–24.9)	1,921	19.7	5,718	19.6
Overweight (25.0–29.9)	2,895	29.7	8,635	29.7
Obese (≥30.0)	3,176	32.5	9,482	32.6
Hypertension	6,774	69.4	20,168	69.4
Diabetes	3,585	36.7	10,669	36.7
Hyperlipidemia	5,098	52.2	15,250	52.5
Age
Years, mean (SD)	67.0	(10.33)	66.7	(10.25)
18–49 years	293	3.0	970	3.3
50–59 years	1,739	17.8	5,291	18.2
60–69 years	4,108	42.1	12,371	42.6
70–79 years	2,249	23.1	6,586	22.7
>80 years	1,369	14.0	3,848	13.2
Distance, miles, mean (SD)	12.4	(12.50)	12.1	(11.89)
Number of primary care visits within 1 year of anchor date, mean (SD)	3.6	(3.53)	3.8	(4.07)
Died within 3 years of anchor date	2,228	22.8	2,679	9.2

Notes: The following variables had missing data: race (cases n=75, controls n=218); marital status (cases n=43, controls, n=198); copay status (cases n=530, controls n=1,575); body mass index (cases n=1,766, controls n=5,231). Diagnoses of diabetes, hyperlipidemia, and hypertension were based on documented ICD-9 codes in the EHR from 2 years prior to the anchor date. Distance was calculated from the centroid of the veteran’s home zip code to the centroid of the nearest VA facility’s zip code. The number of primary care visits includes visits to VA primary care provider in the year prior to the anchor date.

Abbreviations: CRC, colorectal cancer; VA, Veterans Affairs; EHR, electronic health record.

Table 2 Model-estimated odds ratios of being diagnosed CVD risk factors post-CRC diagnosis (CRC survivors vs matched noncancer controls)

	Odds ratio	95% confidence interval	p-value
Hypertension	1.57	1.49–1.64	<0.0001
Diabetes	0.97	0.93–1.02	0.21
Hyperlipidemia	0.50	0.48–0.52	<0.0001

Notes: This depicts the odds ratio of being diagnosed with CVD risk factors in the first year post-CRC diagnosis date (or matched anchor date for noncancer controls) for CRC patients compared to matched controls. The entire sample (n=38,824) was used for these models.

Abbreviations: CRC, colorectal cancer; CVD, cardiovascular disease.

Table 3 Model-estimated odds ratios of CVD risk factor control 1-year post-CRC diagnosis

	Odds ratio	95% confidence interval	p-value
Blood pressure	1.07	1.02–1.13	0.005
A1c	1.04	0.95–1.15	0.364
LDL	0.88	0.81–0.95	<0.001

Notes: This depicts the odds ratio of achieving CVD risk factor control at 1-year post-CRC diagnosis date (or matched anchor date for noncancer controls) for CRC patients compared to matched controls. There were 37,752 patients with blood pressure data, 20,066 patients with A1c data, and 30,196 patients with LDL data.

Abbreviations: CRC, colorectal cancer; CVD, cardiovascular disease; LDL, low-density lipoprotein.

Table 4 Age-stratified analysis of being diagnosed CVD risk factors post-CRC diagnosis (CRC survivors vs matched noncancer controls)

Odds ratio estimate (95% confidence interval)	Hyperlipidemia	Hypertension	Diabetes
Test for interaction p-value	<0.0001	0.0068	0.7425
Case vs control at age 18–49	0.66 (0.50, 0.88)	1.02 (0.78, 1.35)	Not applicable since test for interaction was not significant
Case vs control at age 50–59	0.57 (0.51, 0.63)	1.76 (1.58, 1.96)
Case vs control at age 60–69	0.55 (0.51, 0.59)	1.54 (1.44, 1.66)
Case vs control at age 70–79	0.45 (0.41, 0.49)	1.52 (1.37, 1.69)
Case vs control at age >80	0.33 (0.29, 0.37)	1.63 (1.43, 1.85)

Abbreviations: CRC, colorectal cancer; CVD, cardiovascular disease.

Table 5 Age-stratified analysis of CVD risk factor control 1-year post-CRC diagnosis

Odds ratio estimate (95% confidence interval) p-value	LDL	Blood pressure	A1c
Test for interaction p-value	0.0486	<0.0001	0.0540
Case vs control at age 18–49	0.56 (0.34, 0.92)	0.78 (0.59, 1.03)	Not applicable since test for interaction was not significant
Case vs control at age 50–59	0.83 (0.69, 0.99)	0.94 (0.84, 1.05)
Case vs control at age 60–69	0.86 (0.76, 0.96)	1.03 (0.96, 1.11)
Case vs control at age 70–79	0.93 (0.79, 1.10)	1.24 (1.12, 1.38)
Case vs control at age >80	0.95 (0.74, 1.21)	1.27 (1.11, 1.46)

Abbreviations: LDL, low density lipoprotein; CVD, cardiovascular disease; CRC, colorectal cancer.