The study sample included 3,657 eligible adults with cancer, representing 19.1 million individuals in the US per-year during years 2010 to 2015. Among the eligible adults with cancer, 83.9% (n = 3,040; representing 16 million individuals in the US) had at least one chronic condition (Figure 1). Table 1 compared the characteristics of the adults with cancer and chronic conditions vs. adults with cancer but without chronic conditions. Overall, compared to the group without chronic conditions, adults with chronic conditions showed greater proportions of those reporting age older than 65 years (59.2% vs. 23.3%, p<0.001), obesity (31.9% vs. 17.7%, p<0.001), education lower than college (67.8% vs. 57%, p<0.001), poor to low income (30.5% vs. 21.3%, p<0.001), public insurance coverage (29.9% vs. 14.4%, p<0.001), and poor to fair health status (23.6% vs. 11.2%, p<0.001).
Table 1 Characteristics by chronic conditions in adults with cancer (n=3,657)
Variable
|
Chronic condition (n=3,040)
|
No chronic condition (n=617)
|
p
|
|
n (weighted %)
|
n (weighted %)
|
|
Age category
|
|
|
<0.001
|
18-45
|
300 (7.8)
|
219 (30.5)
|
|
46-64
|
1024 (33.0)
|
263 (46.2)
|
|
65+
|
1716 (59.2)
|
135 (23.3)
|
|
Race
|
|
|
0.006
|
White
|
1872 (74.5)
|
359 (69.3)
|
|
Black
|
368 (5.4)
|
56 (4.6)
|
|
Other
|
800 (20.1)
|
202 (26.2)
|
|
Sex (female)
|
1645 (57.8)
|
374 (56.5)
|
0.178
|
Body mass index
|
|
|
<0.001
|
Underweight
|
45 (1.3)
|
19 (2.6)
|
|
Normal
|
901 (31.6)
|
265 (45.0)
|
|
Overweight
|
1061 (35.1)
|
210 (34.8)
|
|
Obese
|
1033 (31.9)
|
123 (17.7)
|
|
Education
|
|
|
<0.001
|
High School
|
1720 (57.0)
|
319 (49.9)
|
|
College
|
814 (32.2)
|
224 (43.0)
|
|
No degree/other
|
506 (10.8)
|
74 (7.1)
|
|
Family size
|
|
|
<0.001
|
≤ 2
|
2355 (81.6)
|
354 (65.6)
|
|
>2
|
685 (18.4)
|
263 (34.4)
|
|
Geographical region
|
|
|
0.259
|
Northeast
|
515 (17.9)
|
93 (15.3)
|
|
Midwest
|
649 (23.0)
|
131 (22.8)
|
|
South
|
1191 (38.6)
|
206 (36.8)
|
|
West
|
685 (20.5)
|
187 (25.1)
|
|
Married
|
1681 (59.6)
|
394 (65.7)
|
0.034
|
Income categorya
|
|
|
<0.001
|
Poor
|
670 (16.3)
|
97 (11.1)
|
|
Low income
|
475 (14.2)
|
82 (10.3)
|
|
Middle income
|
806 (25.7)
|
170 (24.7)
|
|
High income
|
1089 (43.9)
|
268 (53.9)
|
|
Insurance coverage
|
|
|
<0.001
|
Private
|
1817 (66.9)
|
444 (77.3)
|
|
Public
|
1084 (29.9)
|
115 (14.4)
|
|
Uninsured
|
139 (3.2)
|
58 (8.3)
|
|
Perceived health status
|
|
|
<0.001
|
Excellent/Very good
|
1224 (45.3)
|
399 (70.7)
|
|
Good
|
943 (31.2)
|
134 (18.1)
|
|
Fair/poor
|
873 (23.6)
|
84 (11.2)
|
|
a Poor defined as income <100% of federal poverty line (FPL); low income defined as 100%-199% of FPL; middle income defined as 200%-399% of FPL; high income defined as ≥ 400% of FPL
Figure 2A indicated that the prevalence of common chronic conditions in adults with cancer was higher than in those without cancer. Hypertension (59.7%), hyperlipidemia (53.6%), arthritis (25.6%), diabetes (22.2%), and coronary artery disease (18.2%) were the five most prevalent chronic conditions in US adults with cancer. Additional file 1 lists all chronic conditions, ranked by treated prevalence, in the study sample. Among the top ten prevalent treated chronic conditions, stroke ($2,964), coronary artery disease ($2,787), and cardiac arrhythmias ($2,011) were the costliest in adults with cancer (Figure 2B). Additional file 2 shows annual expenses associated with all individual chronic conditions in cancer and no cancer groups. The proportions of adults with zero, one, two, and three chronic conditions in the cancer group were similar, ranging from 16.1% to 18.7%. However, 29.7% of the adults with cancer reported four or more chronic conditions vs. 9.7% of those without cancer (Figure 3).
Table 2 compared chronic condition-related health care utilization and expenses by cancer. Overall higher health care utilization except ED visits were observed in the cancer group. The medical and total expenses associated with chronic conditions in the cancer group were $1061 ($2990 vs. $1929, p<0.001) and $1399 ($4113 vs. $2714, p<0.001) higher than in no cancer group. The health expenses associated with chronic conditions accounted for 30.3% of total all-cause health expenses. Prescription drug use, hospitalization, and office visits accounted for 27.3%, 26.8%, and 24.4%, respectively, of the chronic condition-related expenses in the cancer group.
Table 2 Chronic condition-related health service utilization patterns and expenses (per-person per-year) by cancer (n=28,108)
|
Cancer
(n=3,040)
|
No cancer
(n=25,068)
|
p
|
Chronic condition-related health service utilization, mean (SE)
|
|
|
|
Number of office visits
|
4.8 (0.2)
|
3.2 (0.1)
|
<0.001
|
Number of outpatient visits
|
0.4 (0.1)
|
0.2 (0.0)
|
<0.001
|
Number of prescriptions
|
6.7 (0.2)
|
4.6 (0.1)
|
<0.001
|
Home health days per month
|
0.4 (0.1)
|
0.3 (0.0)
|
0.002
|
ED visits per 1000 patient months
|
7 (0.5)
|
6.5 (0.5)
|
0.888
|
Hospitalization per 1000 patient months
|
6.6 (0.5)
|
4.7 (0.2)
|
0.018
|
Chronic condition-related health expenses (USD $), mean (SE)
|
|
|
|
Medical expenses
|
2,990 (206)
|
1,929 (87)
|
<0.001
|
Office
|
1,005 (51)
|
602 (17)
|
<0.001
|
Outpatient
|
224 (27)
|
126 (12)
|
0.001
|
ED
|
91 (13)
|
82 (4.4)
|
0.967
|
Hospitalization
|
1,104 (131)
|
826 (69)
|
0.103
|
Home health
|
565 (131)
|
293 (32)
|
<0.001
|
Prescription drugs
|
1,123 (113)
|
784 (33)
|
<0.001
|
Total expenses
|
4,113 (242)
|
2,714 (103)
|
<0.001
|
|
|
|
|
|
ED: emergency department; SE: standard error; USD: United States Dollar
Table 3 All-cause health service utilization patterns and expenses (per-person per-year) by chronic condition in adults with cancer (n=3,657)
|
Chronic condition
(n=3,040)
|
No chronic condition
(n=617)
|
p
|
All-cause health service utilization, mean (SE)
|
|
|
Number of office visits
|
14.3 (0.3)
|
7.5 (0.4)
|
<0.001
|
Number of outpatient visits
|
1.7 (0.1)
|
0.9 (0.1)
|
<0.001
|
Number of prescription fills
|
29.8 (0.8)
|
6.7 (0.5)
|
<0.001
|
Home health days per month
|
5.2 (0.8)
|
0.4 (0.1)
|
<0.001
|
ED visits per 1000 patient months
|
27 (1.1)
|
12 (1.3)
|
<0.001
|
Hospitalization per 1000 patient months
|
23 (1.1)
|
11 (1.4)
|
<0.001
|
All-cause health expenses (USD $),
mean (SE)
|
|
|
|
Medical expenses
|
10,573 (423)
|
6,147 (575)
|
<0.001
|
Office
|
3,499 (110)
|
2,155 (201)
|
<0.001
|
Outpatient
|
1,507 (118)
|
1,038 (151)
|
<0.001
|
ED
|
332 (26)
|
186 (34)
|
<0.001
|
Hospitalization
|
3,885 (267)
|
2,198 (467)
|
<0.001
|
Home health
|
721 (206)
|
49 (17)
|
<0.001
|
Other
|
630 (25)
|
521 (43)
|
<0.001
|
Prescription drugs
|
2,984 (127)
|
1,022 (216)
|
<0.001
|
Total expenses
|
13,557 (465)
|
7,169 (630)
|
<0.001
|
|
|
|
|
|
ED: emergency department; SE: standard error; USD: United States Dollar
Table 3 displays the all-cause health care utilization patterns and expenses by chronic condition in the subgroup of adults with cancer. Overall, the chronic condition group showed higher total health care utilization than the reference group without chronic conditions, including numbers of office visits, outpatient visits, prescription fills, days provided by home health, and events for ED and hospitalization. The total health care expenses in the chronic condition group were $6,388 higher ($13,557 vs. $7,169, p<0.001) than the reference group without chronic condition(s).
Table 4 showed that, after controlling for study sample characteristics, cancer increased chronic condition-related health expenses by 40.3% (p<0.001). In the subgroup of adults with cancer, chronic condition(s) increased total health expenses by 50.7% (p<0.001) after adjustment. The full regression results can be found in Additional files 3 and 4.
Table 4 Associations of chronic conditions on total health expenses and effect of cancer on chronic condition-related health expenses
Dependent variable
|
Independent variable
|
Estimated log coefficient (SE)
|
Change in percent (%)a
|
p
|
Chronic condition-related expensesb
|
Cancer
|
|
|
|
|
No
|
Reference
|
|
|
|
Yes
|
0.34 (0.08)
|
+40.3%
|
<0.001
|
|
|
|
|
|
Total health expensesc
|
Chronic condition
|
|
|
|
|
No
|
Reference
|
|
|
|
Yes
|
0.41 (0.10)
|
+50.7%
|
<0.001
|
|
|
|
|
|
SE: standard error
aThe log coefficients of the independent variables were interpreted as the change in percent
bThe study sample (n=28,108) included eligible adults with chronic conditions. Primary independent variable was cancer (yes/no). Covariates in the regression model for adjustment included respondents’ sociodemographic and health characteristics.
cThe study sample (n=3,657) included a subgroup of adults with cancer. Primary independent variable was chronic condition (yes/no). Covariates in the regression model for adjustment included respondents’ sociodemographic and health characteristics.