Economic burden related to chemotherapy-related adverse events in patients with metastatic breast cancer in an integrated health care system

Figures & data

Table 1 Baseline characteristics of patients with and without adverse events

Patient characteristics	Total first-line patients, N=1,682 (100%)	Patients with chemotherapy-related AE during first line of therapy, N=909 (54%)	Patients without chemotherapy-related AE during first line of therapy, N=773 (46%)
Age <65 years, n (mean ± SD)	1,002 (60±8.1)	545 (53±8.2)	457 (53±8.0)
Age ≥65 years, n (mean ± SD)	680 (73±6.0)	362 (73±5.8)	318 (74±6.2)
Single chemotherapy regimen, n (%)	1,547 (91.97)	830 (91.31)	717 (92.76)
Multiple chemotherapy regimen	135 (8.03)	77 (8.47)	58 (7.5)
Race, n (%)*
Asian/Pacific Islander	150 (8.91)	94 (10.34)	56 (7.24)
Black	290 (17.24)	151 (16.61)	139 (17.98)
Hispanic	179 (30.64)	110 (12.1)	69 (8.93)
Othera	100 (5.94)	49 (5.39)	51 (6.6)
White	963 (57.25)	503 (55.34)	460 (59.51)
Insurance type, n (%)b
Commercial	1,643 (97.68)	879 (96.7)	764 (98.84)
Medicaid	30 (1.78)	20 (2.2)	10 (1.29)
Medicare	667 (39.65)	362 (39.82)	305 (39.46)
Comorbidities, n (%)b
Cerebrovascular disease	46 (2.73)	25 (2.75)	21 (2.72)
Chronic pulmonary disease	199 (11.83)	113 (12.43)	86 (11.13)
Congestive heart failure	64 (3.8)	33 (3.63)	31 (4.01)
Diabetes	275 (16.35)	147 (16.17)	128 (16.56)
Hypertension	718 (42.69)	401 (44.11)	317 (41.01)
Liver disease	14 (0.83)	9 (0.99)	5 (0.65)
Myocardial infarction	34 (2.02)	20 (2.2)	14 (1.81)
Otherc	21 (1.25)	11 (1.21)	10 (1.29)
Peripheral vascular disease	26 (1.55)	19 (2.09)*	7 (0.91)*
Renal disease	154 (9.16)	87 (9.57)	67 (8.67)
Rheumatic disease	30 (1.78)	15 (1.65)	15 (1.94)
Baseline health care resource use
ER patient visits, n (%)	622 (36.97)	348 (38.28)	274 (35.44)
Number of ER visits, mean ± SD	2.0±1.0	2.0±10	20±10
Hospital patient visits, n (%)	622 (36.97)	332 (36.52)	290 (37.52)
Number of hospital visits, mean ± SD	2.0±1.0	2.0±1.0	2.0±10
Hospital days, mean ± SD	3.0 ±4.0	3.0±5.0	3.0±3.0
Number of outpatient visits, mean ± SD	13.0±9.0	13.0±9.0	13.0±9.0

Notes: All patients had at least one or more outpatient visit during the 12 months prior index date.

a Native Hawaiian/other Pacific Islander/Native American/other/unknown.

b Not mutually exclusive, more than one patient could be counted more than once.

c Other includes dementia, peptic ulcer disease, and hemiplegia or paraplegia.

* Statistically significant with P<0.05.

Abbreviations: AE, adverse event; ER, emergency room.

Table 2 Descriptive data on episode of care for AEs

AE category	Total number ofepisodes (%), N=5,475	Number of single episodes (%), N=4,185	Total number of multiple episodes (%), N=1,290	Mean days of multiple episodes duration (SD)
Dermatological	134 (2.45)	113 (2.70)	21 (1.63)	5.5 (4.3)
Dehydration	155 (2.83)	60 (1.43)	95 (7.36)	4.3 (3.2)
Edema	180 (3.29)	159 (3.80)	21 (1.63)	5.2 (5.3)
Gastrointestinal	1,053 (19.23)	775 (18.52)	278 (22.55)	5.3 (4.5)
Hematological	1,807 (33.00)	1,387 (33.14)	420 (32.56)	6.1 (5.6)
Hepatic	79 (1.44)	66 (1.58)	13 (1.01)	4.3 (2.9)
Infections/pyrexia	890 (16.26)	555 (13.26)	335 (25.97)	4.2 (4.1)
Musculoskeletal/pain related	1,177 (21.49)	1,070 (25.57)	107 (8.29)	4.6 (2.9)

Abbreviation: AE, adverse event.

Table 3 Descriptive data on total health care resource costs for each AE category (episode level)

Adverse event category	Outpatient		Outpatient + ER		Outpatient + hospital		Hospital		ER + hospital
	EOC, n	Cost	EOC, n	Cost	EOC, n	Cost	EOC, n	Cost ($)	EOC, n	Cost
Single episodes
Dermatological	111	$10,101	0	–	0	–	2	$10,685	0	–
Alopecia	4	$364	0	–	0	–	0	–	0	–
Injection site reaction	5	$455	0	–	0	–	1	$4,274	0	–
Rash	102	$9,282	0	–	0	–	1	$6,411	0	–
Dehydration	50	$4,550	0	–	0	–	10	$25,644	0	–
Edema	157	$14,287	0	–	0	–	2	$12,822	0	–
Gastrointestinal	741	$67,431	0	–	0	–	34	$288,495	0	–
Constipation	125	$11,375	0	–	0	–	5	$47,014	0	–
Decreased appetite	158	$14,378	0	–	0	–	2	$19,233	0	–
Diarrhea	137	$12,467	0	–	0	–	7	$53,425	0	–
Nausea/vomiting	265	$24,115	0	–	0	–	14	$141,042	0	–
Stomatitis	56	$5,096	0	–	0	–	6	$27,781	0	–
Hematological	1,317	$119,847	0	–	0	–	70	$745,813	0	–
Anemia	901	$81,991	0	–	0	–	46	$542,798	0	–
Leukopenia	128	$11,648	0	–	0	–	1	$6,411	0	–
Neutropenia	187	$17,017	0	–	0	–	16	$136,768	0	–
Thrombocytopenia	101	$9,191	0	–	0	–	7	$59,836	0	–
Hepatic	65	$5,915	0	–	0	–	1	$6,411	0	–
Liver enzymes increased	56	$5,096	0	–	0	–	1	$6,411	0	–
Bilirubin	9	$819	0	–	0	–	0	–	0	–
Infection or pyrexia	498	$45,318	0	–	0	–	57	$438,085	0	–
Infection	457	$41,587	0	–	0	–	46	$354,742	0	–
Pyrexia	41	$3,731	0	–	0	–	11	$83,343	0	–
Musculoskeletal/pain related	1,065	$96,915	0	–	0	–	5	$19,233	0	–
Arthalgia	247	$22,477	0	–	0	–	0	–	0	–
Myalgia	58	$5,278	0	–	0	–	2	$6,411	0	–
Peripheral neuropathy	760	$69,160	0	–	0	–	3	$12,822	0	–
Multiple episodes
Dermatological	0	–	9	$3,285	0	–	0	–	12	$54,131
Alopecia	0	–	1	$365	0	–	0	–	0	–
Injection site reaction	0	–	5	$1,825	0	–	0	–	8	$35,375
Rash	0	–	3	$1,095	0	–	0	–	4	$18,756
Dehydration	23	$7,007	34	$12,410	29	$186,575	0	–	9	$52,886
Edema	0	–	11	$4,015	0	–	0	–	10	$57,575
Gastrointestinal	20	$9,009	143	$52,195	0	–	1	$10,685	114	$1,021,782
Constipation	0	–	31	$11,315	0	–	0	–	36	$322,668
Decreased appetite	0	–	1	$365	0	–	0	–	4	$35,852
Diarrhea	8	$3,549	40	$14,600	0	–	0	–	40	$358,520
Nausea/vomiting	12	$5,460	71	$25,915	0	–	1	$10,685	26	$233,038
Stomatitis	0	–	0	–	0	–	0	–	8	$71,704
Hematological	47	$37,730	115	$41,975	18	$152,650	0	–	240	$2,664,000
Anemia	33	$18,018	82	$29,930	18	$152,650	0	–	155	$1,720,500
Leukopenia	4	$16,891	2	$730	0	–	0	–	5	$55,500
Neutropenia	10	$2,821	23	$8,395	0	–	0	–	63	$699,300
Thrombocytopenia	0	–	8	$2,920	0	–	0	–	17	$188,700
Hepatic	3	$1,092	7	$2,555	0	–	0	–	3	$26,889
Liver enzymes increased	3	$1,092	6	$2,190	0	–	0	–	2	$17,926
Bilirubin	0	–	1	$365	0	–	0	–	1	$8,963
Infection or pyrexia	57	$20,748	86	$31,390	28	$120,158	0	–	164	$1,469,932
Infection	47	$17,108	37	$13,505	17	$77,685	0	–	111	$994,893
Pyrexia	10	$3,640	49	$17,885	11	$42,473	0	–	53	$475,039
Musculoskeletal/pain related	53	$13,104	26	$4,380	7	$26,834	0	–	21	$80,667
Arthralgia	2	$546	13	$4,745	0	–	0	–	5	$44,815
Myalgia	3	$1,092	1	$365	0	–	0	–	7	$62,741
Peripheral neuropathy	48	$13,104	12	$4,380	7	$26,834	0	–	9	$80,667

Abbreviations: ER, emergency room; EOC, episode of care; AE, adverse event.

Table 4 Descriptive economic data on 909 patients with AE during their first-line chemotherapy regimen

EOC with AE categories	Patients, n (%)	Total EOC, n (%)	Total EOC cost per adverse event category cost ($)	Total other medication cost ($)a	Average cost per EOCb (±SD)
Single EOC, n=769
Dermatological	68 (8.8)	113 (2.7)	$20,786	$18,009	$2,982 (±$518)
Dehydration	43 (5.6)	60 (1.4)	$30,194	$34,719	$2,135 (±$1,132)
Edema	94 (12.2)	159 (3.8)	$27,109	$22,399	$3,489 (±$1,365)
Gastrointestinal	378 (49.2)		$355,926	$196,932	$4,809 (±$1,001)
Hematological	333 (43.3)	1,387 (33.1)	$865,660	$468,248	$6,779 (±$2,218)
Hepatic	26 (3.4)	66 (1.6)	$12,326	$14,125	$3,794 (±$1,280)
Infection or pyrexia	272 (35.4)	555 (13.2)	$483,403	$229,871	$4,733 (±$2,258)
Musculoskeletal/pain related	283 (36.8)	1,070 (25.6)	$116,148	$182,466	$2,614 (±$580)
Total average cost per single EOC					$30,936 (±$10,352)
Multiple EOC, n=560
Dermatological	21 (4.8)	21 (1.5)	$57,416	$30,412	$3,886 (±$2,051)
Dehydration	85 (15.2)	95 (7.4)	S258.878	$83,219	$4,224 (±$805)
Edema	19 (3.4)	21 (1.6)	$61,590	$35, 383	$4,923 (±$1,020)
Gastrointestinal	219 (39.1)	278 (21.6)	$1,093,671	$256,493	$6,287 (±$1,752)
Hematological	255 (45.5)	420 (32.6)	$2,896,355	$534,353	$7,283 (±$1,181)
Hepatic	13 (2.3)	13 (1.0)	$30,536	$13,282	$3,732 (±$1,599)
Infection or pyrexia	204 (36.4)	335 (25.9)	$1,642,228	$394,352	$5,429 (±$1,858)
Musculoskeletal/pain related	72 (12.9)	107 (8.2)	$124,985	$103,446	$3,460 (±$805)
Total average cost per multiple EOC					$35,223 (±$11,071)

Notes:

a Chemotherapy cost is not included in the total other medication costs.

b Average cost per EOC includes the average cost of other medications.

Abbreviations: AE, adverse event; EOC, episode of care.