Health care-resource utilization before and after natalizumab initiation in multiple sclerosis patients in the US

Figures & data

Figure 1 Sample attrition.

Abbreviations: MS, multiple sclerosis; DMT, disease-modifying treatment.

Table 1 Baseline demographic and clinical characteristics

	All natalizumab initiators		Prior DMT use*		No prior DMT use*		P-value
	n=1,458		n=1,025		n=433
	n/Mean	%/SD	n/Mean	%/SD	n/Mean	%/SD
Age (mean, SD)	45.2	10.5	45.4	10.2	44.7	11.0	0.271
Age range, years
18–34	219	15.0	151	14.7	68	15.7	0.036
35–44	401	27.5	265	25.9	136	31.4
45–54	499	34.2	376	36.7	123	28.4
55–64	310	21.3	214	20.9	96	22.2
65+	29	2.0	19	1.9	10	2.3
Sex
Male	376	25.8	252	24.6	124	28.6	0.106
Female	1,082	74.2	773	75.4	309	71.4
US geographic region
Northeast	66	4.5	52	5.1	14	3.2	0.143
North Central	490	33.6	328	32.0	162	37.4
South	599	41.1	424	41.4	175	40.4
West	296	20.3	217	21.2	79	18.2
Unknown	7	0.5	4	0.4	3	0.7
Insurance type
Comprehensive	78	5.3	51	5.0	27	6.2	0.762
HMO	219	15.0	156	15.2	63	14.5
POS	159	10.9	117	11.4	42	9.7
PPO or EPO	915	62.8	640	62.4	275	63.5
CDHP or HDHP	56	3.8	41	4.0	15	3.5
Other/unknown	31	2.1	20	2.0	11	2.5
Comorbid conditions
Anxiety	70	4.8	50	4.9	20	4.6	0.833
Arthritis (RA or OA)	71	4.9	53	5.2	18	4.2	0.411
Depression	230	15.8	168	16.4	62	14.3	0.321
Diabetes	84	5.8	54	5.3	30	6.9	0.214
Gastrointestinal disease and symptoms	208	14.3	141	13.8	67	15.5	0.392
High blood pressure	250	17.1	182	17.8	68	15.7	0.342
Neuropathic pain	141	9.7	92	9.0	49	11.3	0.167
Non-skin cancer	137	9.4	98	9.6	39	9.0	0.740
Other chronic pain	540	37.0	385	37.6	155	35.8	0.524
Skin cancer	129	8.8	98	9.6	31	7.2	0.140
Thyroid disease	118	8.1	85	8.3	33	7.6	0.668
Urinary tract infection	42	2.9	26	2.5	16	3.7	0.227

Notes:

* No prior DMT-use group had no other DMT (interferon beta-1a, interferon beta-1b, glatiramer acetate, or fingolimod) in preperiod, prior DMT use group did. Age, Sex, geographic region, and insurance-plan type measured as of patient’s index date. Presence of comorbid conditions measured during the 12-month preindex period.

Abbreviations: DMT, disease-modifying treatment; SD, standard deviation; HMO, health maintenance organization; POS, point-of service plan; PPO, preferred provider organization; EPO, exclusive provider organization; HDHP, high-deductible health plan; RA, rheumatoid arthritis; OA, osteoarthritis; CDPHP, consumer-directed health plan.

Figure 2 MS-related inpatient utilization in the years prior to and following natalizumab initiation.

Abbreviations: MS, multiple sclerosis; DMT, disease-modifying treatment.

Table 2 Comparison of pre- versus postperiod inpatient and corticosteroid utilization and expenditures by group (2012 US $)

	Preperiod		Postperiod		Relative change (post-/pre-)	P-value
	n/mean	%/SD	n/mean	%/SD
All natalizumab initiators (n=1,458)
All-cause inpatient admissions
Mean expenditures among all patients, (mean, SD)	$3,787	$16,526	$2,625	$12,737	−30.7%	0.024
Patients with an inpatient admission (n, %)	207	14.2%	150	10.3%	−27.5%	0.001
Median expenditures for those with an admission*	$14,015	–	$12,226	–	−12.8%	<0.001
Average LOS for those with an admission (mean, SD)	9.13	12.30	8.03	13.91	−12.0%	0.024
MS-related inpatient admissions
Mean expenditure among all patients, (mean, SD)	$1,810	$11,760	$479	$6,190	−73.5%	<0.001
Patients with an inpatient admission (n, %)	111	7.6%	35	2.4%	−68.5%	<0.001
Median expenditure for those with an admission*	$12,078	–	$9,784	–	−19.0%	<0.001
Average LOS for those with an admission (mean, SD)	7.12	8.75	6.26	7.61	−12.1%	0.005
Corticosteroids
IV and oral corticosteroid expenditure (mean, SD)	$119	$275	$19	$71	−84.4%	<0.001
Patients with any IV or oral corticosteroid use (n, %)	901	61.8%	445	30.5%	−50.6%	<0.001
IV corticosteroid expenditure (mean, SD)	$107	$270	$15	$69	−85.6%	<0.001
Patients with IV corticosteroid use (n, %)	640	43.9%	255	17.5%	−60.2%	<0.001
Oral corticosteroid expenditure (mean, SD)	$12	$53	$3	$14	−73.9%	<0.001
Patients with oral corticosteroid use (n, %)	600	41.2%	283	19.4%	−52.8%	<0.001
Natalizumab initiators with no prior DMT use (n=433)†
All-cause inpatient admissions
Expenditure among all patients (mean, SD)	$4,351	$21,372	$2,238	$13,555	−48.5%	0.059
Patients with an inpatient admission (n, %)	64	14.8%	41	9.5%	−35.9%	0.017
Median expenditures for those with an admission*	$12,790	–	$10,968	–	−14.2%	0.013
Average LOS for those with an admission (mean, SD)	10.13	15.89	7.24	12.36	−28.5%	0.003
MS-related inpatient admissions
Expenditure among all patients (mean, SD)	$2,127	$15,866	$632	$9,887	−70.3%	0.056
Patients with an inpatient admission (n, %)	35	8.1%	8	1.8%	−77.1%	<0.001
Median expenditures for those with an admission*	$9,642	–	$8,495	–	−11.9%	<0.001
Average LOS for those with an admission (mean, SD)	7.40	11.23	7.88	11.10	6.4%	0.532
Corticosteroids
IV and oral corticosteroid expenditure (mean, SD)	$85	$252	$17	$69	−80.1%	<0.001
Patients with any IV or oral corticosteroid use (n, %)	219	50.6%	121	27.9%	−44.7%	<0.001
IV corticosteroid expenditure (mean, SD)	$79	$249	$14	$65	−82.4%	<0.001
Patients with IV corticosteroid use (n, %)	148	34.2%	64	14.8%	−56.8%	<0.001
Oral corticosteroid expenditures (mean, SD)	$6	$27	$3	$14	−51.9%	0.018
Patients with oral corticosteroid use (n, %)	127	29.3%	77	17.8%	−39.4%	<0.001
Natalizumab initiators with prior DMT use (n=1,025)†
All-cause inpatient admissions
Expenditures among all patients (mean, SD)	$3,548	$13,989	$2,789	$12,379	−21.4%	0.174
Patients with an inpatient admission (n, %)	143	14.0%	109	10.6%	−23.8%	0.022
Median expenditure for those with an admission*	$15,171	–	$12,668	–	−16.5%	0.004
Average LOS for those with an admission (mean, SD)	8.65	10.33	8.33	14.49	−3.7%	0.669
MS-related inpatient admissions
Expenditure among all patients (mean, SD)	$1,676	$9,515	$414	$3,641	−75.3%	<0.001
Patients with an inpatient admission (n, %)	76	7.4%	27	2.6%	−64.5%	<0.001
Median expenditure for those with an admission*	$13,409	–	$10,085	–	−24.8%	<0.001
Average LOS for those with an admission (mean, SD)	6.99	7.43	5.78	6.44	−17.3%	<0.001
Corticosteroids
IV and oral corticosteroid expenditure (mean, SD)	$133	$284	$19	$72	−85.5%	<0.001
Patients with any IV or oral corticosteroid use (n, %)	682	66.5%	324	31.6%	−52.5%	<0.001
IV corticosteroid expenditure (mean, SD)	$119	$278	$16	$70	−86.4%	<0.001
Patients with IV corticosteroid use (n, %)	492	48.0%	191	18.6%	−61.2%	<0.001
Oral corticosteroid expenditure (mean, SD)	$14	$60	$3	$14	−78.0%	<0.001
Patients with oral corticosteroid use (n, %)	473	46.1%	206	20.1%	−56.4%	<0.001

Notes:

* Medians are reported among patients with non-zero expenditure; sign-rank tests comparing the median values of all patients, including those with no expenditure.

† No prior DMT-use group had no other DMT (interferon beta-1a, interferon beta-1b, glatiramer acetate. or fingolimod) in preperiod, prior DMT-use group did.

Abbreviations: SD, standard deviation; MS, multiple sclerosis; LOS, length of stay; IV, intravenous; DMT, disease-modifying treatment.

Figure 3 MS-related inpatient utilization and costs (2012 US $) in the years prior to and following natalizumab initiation.

Abbreviations: MS, multiple sclerosis; DMT, disease-modifying treatment.