Cost per patient-year in response using a claims-based algorithm for the 2 years following biologic initiation in patients with rheumatoid arthritis

Figures & data

Table 1. Patient selection and attrition reasons.

	Patients selected
Attrition reason	n	%^a
All patients with a claim for a biologic between January 1, 2009 and July 1, 2011	174,370
AND do not have ≥2 different biologics indicated for RA treatment^b on the index date^c	174,354	100.0%
AND are ≥18 years of age on the index date	168,668	96.7%
AND are <63 years of age on the index date	161,208	95.6%
AND continuous enrollment and pharmacy data pre-index^d	92,184	57.2%
AND with no claims for any biologics indicated for RA treatment pre-index	46,991	51.0%
AND with no claims for other biologics pre-index	46,790	99.6%
AND continuous enrollment and pharmacy data post-index^e	26,290	56.2%
AND a diagnosis on a medical claim of RA (ICD-9-CM code 714.0x) pre-index	9607	36.5%
AND no diagnosis of any excluded condition^f pre-index	8778	91.4%
AND no claims for any biologics indicated for RA treatment before the FDA approval^g	8777	100.0%
AND no claims for SC biologic with an HCPCS code	8564	97.6%
AND no claims for IV biologic with an NDC code	8193	95.7%
Patients available for the study	8193

HCPCS, Healthcare Common Procedure Coding System; IV, intravenous; NDC, national drug code; RA, rheumatoid arthritis; SC, subcutaneous.

^aPercentage of patients from prior eligibility criterion that remained after application of the attrition reason.

^bAbatacept, adalimumab, certolizumab, etanercept, golimumab, or infliximab.

^cIndex date = date of the first claim between January 1, 2009 and July 1, 2011 for one of these biologics.

^dPre-index = 6 months before the index date (180 days before and including the index date).

^ePost-index = 2 years (730 days) after the index date.

^fJuvenile idiopathic arthritis, non-Hodgkin’s lymphoma, chronic lymphocytic leukemia, psoriasis, psoriatic arthritis, ankylosing spondylitis, Crohn’s disease, or ulcerative colitis pre-index.

^gCertolizumab before May 2009, golimumab before April 2009, or tocilizumab before January 2010.

Table 2. Demographics.

	All Patients (n = 8193)	Etanercept (n = 3532)	Abatacept (n = 553)	Adalimumab (n = 2595)	Certolizumab (n = 184)	Golimumab (n = 340)	Infliximab (n = 989)
Age, mean (SD)	49.0 (9.6)	48.4 (9.9)	50.7 (9.0)	48.7 (9.6)	48.7 (10.1)	50.4 (8.6)	50.6 (9.0)
Gender, n (%)
Male	1787 (21.8)	743 (21.0)	98 (17.7)	626 (24.1)	36 (19.6)	78 (22.9)	206 (20.8)
Female	6406 (78.2)	2789 (79.0)	455 (82.3)	1969 (75.9)	148 (80.4)	262 (77.1)	783 (79.2)
Geographic region, n (%)
Northeast	1328 (16.2)	599 (17.0)	95 (17.2)	389 (15.0)	52 (28.3)	46 (13.5)	147 (14.9)
North Central	1967 (24.0)	868 (24.6)	136 (24.6)	626 (24.1)	26 (14.1)	75 (22.1)	236 (23.9)
South	3309 (40.4)	1330 (37.7)	230 (41.6)	1101 (42.4)	84 (45.7)	153 (45.0)	411 (41.6)
West	1453 (17.7)	675 (19.1)	81 (14.6)	441 (17.0)	20 (10.9)	62 (18.2)	174 (17.6)
Unknown	136 (1.7)	60 (1.7)	11 (2.0)	38 (1.5)	2 (1.1)	4 (1.2)	21 (2.1)
Index year, n (%)
2009	3995 (48.8)	1761 (49.9)	305 (55.2)	1220 (47.0)	39 (21.2)	111 (32.6)	559 (56.5)
2010	2883 (35.2)	1205 (34.1)	176 (31.8)	934 (36.0)	96 (52.2)	181 (53.2)	291 (29.4)
2011	1315 (16.1)	566 (16.0)	72 (13.0)	441 (17.0)	49 (26.6)	48 (14.1)	139 (14.1)

Table 3. Clinical characteristics.

		Index biologic
	All patients (n = 8193)	Etanercept (n = 3532)	Abatacept (n = 553)	Adalimumab (n = 2595)	Certolizumab (n = 184)	Golimumab (n = 340)	Infliximab (n = 989)
DCI^a, mean (SD)	1.3 (0.7)	1.3 (0.7)	1.4 (1.0)	1.2 (0.7)	1.3 (0.7)	1.3 (0.8)	1.2 (0.9)
Prior^a DMARD utilization, n (%)
Methotrexate	5188 (63.3%)	2227 (63.1%)	281 (50.8%)	1691 (65.2%)	114 (62.0%)	219 (64.4%)	656 (66.3%)
Hydroxychloroquine	1943 (23.7%)	907 (25.7%)	129 (23.3%)	617 (23.8%)	39 (21.2%)	70 (20.6%)	181 (18.3%)
Leflunomide	1019 (12.4%)	421 (11.9%)	98 (17.7%)	309 (11.9%)	24 (13.0%)	55 (16.2%)	112 (11.3%)
Sulfasalazine	672 (8.2%)	314 (8.9%)	44 (8.0%)	224 (8.6%)	7 (3.8%)	24 (7.1%)	59 (6.0%)
Concomitant^b DMARD utilization, n (%)
Methotrexate	4284 (52.3%)	1769 (50.1%)	224 (40.5%)	1464 (56.4%)	89 (48.4%)	184 (54.1%)	554 (56.0%)
Hydroxychloroquine	1327 (16.2%)	614 (17.4%)	96 (17.4%)	418 (16.1%)	24 (13.0%)	46 (13.5%)	129 (13.0%)
Leflunomide	651 (7.9%)	262 (7.4%)	69 (12.5%)	181 (7.0%)	23 (12.5%)	37 (10.9%)	79 (8.0%)
Sulfasalazine	356 (4.3%)	154 (4.4%)	26 (4.7%)	127 (4.9%)	5 (2.7%)	14 (4.1%)	30 (3.0%)
Oral glucocorticoid utilization, n (%)
Prior^a	4710 (57.5%)	2044 (57.9%)	323 (58.4%)	1486 (57.3%)	104 (56.5%)	201 (59.1%)	552 (55.8%)
Concomitant^b	2988 (36.5%)	1226 (34.7%)	247 (44.7%)	944 (36.4%)	67 (36.4%)	134 (39.4%)	370 (37.4%)

DCI, Deyo-Charlson comorbidity index; DMARD, disease-modifying antirheumatic drug.

^aMeasured 6 months pre-index (including the index date).

^bMeasured starting on the index date and going through day 90.

Figure 1. Treatment effectiveness over 2 years of follow-up.

Table 4. Treatment failures and response duration.

		Index biologic
	All patients (n = 8193)	Etanercept (n = 3532)	Abatacept (n = 553)	Adalimumab (n = 2595)	Certolizumab (n = 184)	Golimumab (n = 340)	Infliximab (n = 989)
Any treatment failure event, n (%)
Yes, n (%)	6964 (85.0%)	2892 (81.9%)	512 (92.6%)	2176 (83.9%)	156 (84.8%)	293 (86.2%)	935 (94.5%)
p-Value vs etanercept^a	–	–	<0.001	0.044	0.317	0.048	<0.001
Failure events per patient, n (%)
Mean (SD) overall	3.24 (2.42)	2.95 (2.28)	4.35 (2.62)	3.06 (2.35)	3.33 (2.50)	3.04 (2.31)	4.20 (2.59)
p-Value vs etanercept^a	–	–	<0.001	0.070	0.030	0.483	<0.001
Mean (SD) among patients with ≥1 event	3.81 (2.17)	3.60 (2.01)	4.70 (2.40)	3.65 (2.11)	3.92 (2.24)	3.53 (2.12)	4.44 (2.45)
Time to first failure, days
Mean (SD)	194.6 (177.4)	197.5 (179.5)	189.4 (168.5)	194.4 (176.1)	120.3 (136.5)	210.7 (188.7)	196.6 (178.5)
Duration of response, days^b
Mean (SD)	526.0 (137.2)	538.3 (136.5)	482.3 (138.4)	534.7 (134.9)	524.0 (135.2)	537.0 (134.0)	480.0 (132.2)
p-Value vs etanercept^a	–	–	<0.001	0.301	0.165	0.864	<0.001

^aPairwise comparison to etanercept by t-test for continuous comparisons and chi square (Fisher's Exact Test) for dichotomous comparisons.

^bBased on the primary analysis with a 90-day non-response window for each failure event.

Figure 2. Mean (+SD) RA-related healthcare costs over 2 years of follow-up. Includes medical and pharmacy claims with a primary diagnosis of RA (ICD 714.0x).

Table 5. Mean (±SD) biologic costs over 2 years of follow-up.

	Index biologic
Contribution of index biologic and non-index biologic to total	Etanercept (n = 3532)	Abatacept (n = 553)	Adalimumab (n = 2595)	Certolizumab (n = 184)	Golimumab (n = 340)	Infliximab (n = 989)
Etanercept	$28,210 ± $17,136	$866 ± $4551	$2114 ± $7004	$1710 ± $6876	$1827 ± $6727	$856 ± $4298
Abatacept	$743 ± $5004	$29,321 ± $28,802	$845 ± $6106	$949 ± $5173	$699 ± $3511	$2174 ± $9751
Adalimumab	$2581 ± $8287	$528 ± $3566	$29,174 ± $19,519	$2713 ± $10,204	$2194 ± $7729	$710 ± $3920
Certolizumab	$498 ± $3222	$423 ± $3174	$510 ± $3298	$25,871 ± $17,686	$1032 ± $4734	$165 ± $1681
Golimumab	$632 ± $4139	$756 ± $4254	$677 ± $4080	$236 ± $2265	$26,829 ± $17,858	$393 ± $2786
Infliximab	$684 ± $5541	$1600 ± $9499	$867 ± $6524	$355 ± $3409	$729 ± $5212	$32,952 ± $29,079
Tocilizumab	$251 ± $3376	$1546 ± $8327	$368 ± $3174	$1066 ± $5900	$705 ± $3976	$557 ± $3641
Rituximab	$548 ± $4798	$2470 ± $10,731	$528 ± $4487	$748 ± $5122	$757 ± $4827	$765 ± $5547
Anakinra	$4 ± $124	$0 ± $0	$6 ± $293	$47 ± $486	$0 ± $0	$6 ± $194

Figure 3. Average (+95% CI) cost per patient-year in response by index biologic. *p < 0.05 vs etanercept.