Identifying disability level in multiple sclerosis patients in a U.S.-based health plan claims database

Figures & data

Figure 1. Patient attrition.

Table 1. Characteristics of the full sample.

	Full sample patients		Patients with 1-year post-index eligibility
			Mild disability		Moderate disability		Severe disability		p Value
	(N = 45,687)		(n = 29,972)		(n = 9,916)		(n = 5,799)
Age group (n, %)
20–34 years	5,595	12.2%	3,914	13.1%	1,095	11.0%	586	10.1%	<.0001
35–44 years	10,505	23.0%	7,351	24.5%	2,084	21.0%	1,070	18.5%
45–54 years	14,901	32.6%	9,951	33.2%	3,219	32.5%	1,731	29.9%
55–64 years	12,367	27.1%	7,575	25.3%	2,924	29.5%	1,868	32.2%
65+ years	2,319	5.1%	1,181	3.9%	594	6.0%	544	9.4%
Age (continuous)
Mean	48.5		47.7		49.4		50.9		<.0001
SD	11.1		10.9		11.2		11.8
Median	49		48		50		52
Gender (n, %)
Male	10,985	24.0%	7,082	23.6%	2,527	25.5%	1,376	23.7%	.0007
Female	34,702	76.0%	22,890	76.4%	7,389	74.5%	4,423	76.3%
Geographic region (n, %)
Northeast	13,055	28.6%	8,606	28.7%	2,828	28.5%	1,621	28.0%	<.0001
Midwest	14,377	31.5%	9,562	31.9%	2,996	30.2%	1,819	31.4%
South	12,441	27.2%	7,944	26.5%	2,893	29.2%	1,604	27.7%
West	4,992	10.9%	3,261	10.9%	1,065	10.7%	666	11.5%
Unknown	822	1.8%	599	2.0%	134	1.4%	89	1.5%
Payer type (n, %)
Commercial/self-insured	43,212	94.6%	28,517	95.1%	9,420	95.0%	5,275	91.0%	<.0001
Medicaid	1,420	3.1%	825	2.8%	286	2.9%	309	5.3%
Medicare	734	1.6%	402	1.3%	153	1.5%	179	3.1%
Unknown	321	0.7%	228	0.8%	57	0.6%	36	0.6%
Index year (n, %)
2012	32,111	70.3%	21,013	70.1%	6,981	70.4%	4,117	71.0%	<.0001
2013	4,822	10.6%	3,409	11.4%	904	9.1%	509	8.8%
2014	3,267	7.2%	2,109	7.0%	717	7.2%	441	7.6%
2015	3,480	7.6%	2,293	7.7%	714	7.2%	473	8.2%
2016	2,007	4.4%	1,148	3.8%	600	6.1%	259	4.5%
Charlson comorbidity index (CCI) (n, %)
0	31,982	70.0%	22,839	76.2%	6,256	63.1%	2,887	49.8%	<.0001
1	7,737	16.9%	4,673	15.6%	1,926	19.4%	1,138	19.6%
2	3,613	7.9%	1,673	5.6%	1,017	10.3%	923	15.9%
3	1,229	2.7%	431	1.4%	406	4.1%	392	6.8%
4+	1,126	2.5%	356	1.2%	311	3.1%	459	7.9%
Mean	0.5		0.4		0.7		1.1		<.0001
SD	1.1		0.9		1.2		1.6
Median	0		0		0		1
Common comorbid conditions (n, %)
Chronic pain/fibromyalgia	5,588	12.2%	2,625	8.8%	1,848	18.6%	1,115	19.2%	<.0001
Diabetes	3,875	8.5%	2,113	7.0%	974	9.8%	788	13.6%	<.0001
Dyslipidemia	12,793	28.0%	7,600	25.4%	3,162	31.9%	2,031	35.0%	<.0001
Hypertension	12,402	27.1%	7,142	23.8%	3,130	31.6%	2,130	36.7%	<.0001
Osteoarthritis	19,582	42.9%	10,553	35.2%	5,934	59.8%	3,095	53.4%	<.0001
Smoking or history of smoking	3,962	8.7%	2,183	7.3%	1,013	10.2%	766	13.2%	<.0001
Thyroid disease	5,826	12.8%	3,473	11.6%	1,471	14.8%	882	15.2%	<.0001
MS-related medication use (n, %)
Any disease-modifying therapy (DMT) use	21,487	47.0%	14,701	49.0%	4,427	44.6%	2,359	40.7%	<.0001
Alemtuzumab	1	0.0%	0	0.0%	1	0.0%	0	0.0%	.3191
Daclizumab	1	0.0%	0	0.0%	1	0.0%	0	0.0%	.3184
Dimethyl fumarate	148	0.7%	113	0.8%	26	0.6%	9	0.4%	.0709
Fingolimod	1,332	6.2%	815	5.5%	330	7.5%	187	7.9%	<.0001
Glatiramer acetate	8,322	38.7%	5,626	38.3%	1,774	40.1%	922	39.1%	.0907
Interferon b-1a	8,434	39.3%	6,043	41.1%	1,582	35.7%	809	34.3%	<.0001
Interferon b-1b	2,168	10.1%	1,477	10.0%	457	10.3%	234	9.9%	.8308
Mitoxantrone	27	0.1%	9	0.1%	10	0.2%	8	0.3%	.0002
Natalizumab	2,210	10.3%	1,224	8.3%	591	13.3%	395	16.7%	<.0001
Pegylated interferon b-1a	11	0.1%	9	0.1%	1	0.0%	1	0.0%	.7987
Teriflunomide	28	0.1%	25	0.2%	3	0.1%	0	0.0%	.0452
Rituximab	119	0.6%	53	0.4%	36	0.8%	30	1.3%	<.0001
No DMT use	24,200	53.0%	15,271	51.0%	5,489	55.4%	3,440	59.3%	<.0001
Baclofen	5,514	12.2%	2,270	7.7%	1,834	18.5%	1,410	24.3%	<.0001
Relapse
Patients with a relapse in inpatient or outpatient setting (n, %)	5,995	13.1%	2,640	8.8%	1,853	18.7%	1,502	25.9%	<.0001
Number of relapses in all patients
Mean	0.4		0.2		0.5		1.1		<.0001
SD	1.9		0.9		1.8		4.1
Median	0.0		0.0		0.0		0.0
MS-related symptoms and secondary conditions (n, %)
Anxiety	4,973	11.0%	2,593	8.8%	1,428	14.4%	952	16.4%	<.0001
Depression	7,650	17.0%	3,909	13.3%	2,085	21.0%	1,656	28.6%	<.0001
Eye symptoms	1,518	3.4%	601	2.0%	539	5.4%	378	6.5%	<.0001
Fatigue	10,783	23.9%	5,165	17.6%	3,359	33.9%	2,259	39.0%	<.0001
Fractures	142	0.3%	48	0.2%	56	0.6%	38	0.7%	<.0001
Irritable bowel syndrome	906	2.0%	474	1.6%	281	2.8%	151	2.6%	<.0001
Muscular weakness	3,504	7.8%	0	0.0%	2,330	23.5%	1,174	20.2%	<.0001
Osteoporosis	1,544	3.4%	709	2.4%	455	4.6%	380	6.6%	<.0001
Pyramidal symptoms	5,720	12.7%	0	0.0%	4,111	41.5%	1,609	27.7%	<.0001
Sensory problems	9,249	20.5%	4,644	15.8%	2,994	30.2%	1,611	27.8%	<.0001
Sleep disturbance	4,732	10.5%	2,362	8.0%	1,447	14.6%	923	15.9%	<.0001

Table 2. Characteristics of the core sample.

	Core sample patients		Patients with 1-year post-index eligibility
			Mild disability		Moderate disability		Severe disability		p Value
	(N = 1,599)
			(n = 931)		(n = 442)		(n = 226)
Age group (n, %)
20–34 years	160	10.0%	105	11.3%	38	8.6%	17	7.5%	<.0001
35–44 years	358	22.4%	241	25.9%	76	17.2%	41	18.1%
45–54 years	524	32.8%	288	30.9%	169	38.2%	67	29.6%
55–64 years	489	30.6%	268	28.8%	132	29.9%	89	39.4%
65+ years	68	4.3%	29	3.1%	27	6.1%	12	5.3%
Age (continuous)
Mean	49.3		48.2		50.4		51.3		<.0001
SD	10.7		10.6		10.7		10.6
Median	50		49		51		54
Gender (n, %)
Male	352	22.0%	201	21.6%	105	23.8%	46	20.4%	.5376
Female	1,247	78.0%	730	78.4%	337	76.2%	180	79.6%
Geographic region (n, %)
Northeast	764	47.8%	447	48.0%	225	50.9%	92	40.7%	.0003
Midwest	347	21.7%	222	23.8%	86	19.5%	39	17.3%
South	332	20.8%	184	19.8%	79	17.9%	69	30.5%
West	156	9.8%	78	8.4%	52	11.8%	26	11.5%
Payer type (n, %)
Commercial/self-insured	1,528	95.6%	903	97.0%	414	93.7%	211	93.4%	.0115
Medicaid	14	0.9%	7	0.8%	5	1.1%	2	0.9%
Medicare	57	3.6%	21	2.3%	23	5.2%	13	5.8%
Index year (n, %)
2012	1,277	79.9%	750	80.6%	357	80.8%	170	75.2%	.0123
2013	129	8.1%	87	9.3%	23	5.2%	19	8.4%
2014	89	5.6%	48	5.2%	28	6.3%	13	5.8%
2015	66	4.1%	29	3.1%	20	4.5%	17	7.5%
2016	38	2.4%	17	1.8%	14	3.2%	7	3.1%
Charlson comorbidity index (CCI) (n, %)
0	1,127	70.5%	718	77.1%	287	64.9%	122	54.0%	<.0001
1	249	15.6%	141	15.2%	73	16.5%	35	15.5%
2	132	8.3%	52	5.6%	48	10.9%	32	14.2%
3	50	3.1%	14	1.5%	16	3.6%	20	8.9%
4+	41	2.6%	6	0.6%	18	4.1%	17	7.5%
Mean	0.6		0.3		0.7		1.2		<.0001
SD	1.2		0.8		1.3		1.8
Median	0		0		0		0
Common comorbid conditions (n, %)
Chronic pain/fibromyalgia	189	11.8%	74	8.0%	72	16.3%	43	19.0%	<.0001
Diabetes	140	8.8%	61	6.6%	45	10.2%	34	15.0%	.0001
Dyslipidemia	494	30.9%	245	26.3%	167	37.8%	82	36.3%	<.0001
Hypertension	440	27.5%	221	23.7%	141	31.9%	78	34.5%	.0003
Osteoarthritis	688	43.0%	348	37.4%	237	53.6%	103	45.6%	<.0001
Smoking or history of smoking	145	9.1%	67	7.2%	44	10.0%	34	15.0%	.0008
Thyroid disease	243	15.2%	132	14.2%	64	14.5%	47	20.8%	.0403
MS-related medication use (n, %)
Any disease-modifying therapy (DMT) use	938	58.7%	576	61.9%	256	57.9%	938	58.7%	.0039
Dimethyl fumarate	2	0.2%	1	0.2%	0	0.0%	1	0.9%	.2863
Fingolimod	49	5.2%	23	4.0%	12	4.7%	14	13.2%	.0004
Glatiramer acetate	365	39.0%	221	38.4%	109	42.7%	35	33.0%	.2045
Interferon b-1a	393	42.0%	257	44.7%	98	38.4%	38	35.8%	.0956
Interferon b-1b	84	9.0%	51	8.9%	24	9.4%	9	8.5%	.9523
Mitoxantrone	1	0.1%	0	0.0%	1	0.4%	0	0.0%	.3867
Natalizumab	85	9.1%	41	7.1%	28	11.0%	16	15.1%	.0149
Rituximab	3	0.2%	2	0.2%	1	0.2%	0	0.0%	1.0000
No DMT use	661	41.3%	355	38.1%	186	42.1%	120	53.1%	.0002
Baclofen	260	16.3%	95	10.2%	97	22.1%	68	30.1%	<.0001
Relapse
Patients with a relapse in inpatient or outpatient setting (n, %)	255	15.9%	102	11.0%	87	19.7%	66	29.2%	<.0001
Number of relapses in all patients
Mean	0.4		0.2		0.5		0.9		<.0001
SD	1.5		1.2		1.5		2.2
Median	0.0		0.0		0.0		0.0
MS-related symptoms and secondary conditions (n, %)
Anxiety	178	11.2%	84	9.1%	62	14.1%	32	14.2%	.0065
Depression	317	19.9%	151	16.3%	108	24.6%	58	25.7%	<.0001
Eye symptoms	55	3.5%	14	1.5%	23	5.2%	18	8.0%	<.0001
Fatigue	415	26.1%	181	19.5%	140	31.9%	94	41.6%	<.0001
Fractures	6	0.4%	1	0.1%	5	1.1%	0	0.0%	.0157
Irritable bowel syndrome	30	1.9%	14	1.5%	10	2.3%	6	2.7%	.4059
Muscular weakness	139	8.7%	0	0.0%	91	20.7%	48	21.2%	<.0001
Osteoporosis	67	4.2%	23	2.5%	28	6.3%	16	7.1%	.0002
Pyramidal symptoms	229	14.4%	0	0.0%	164	37.4%	65	28.8%	<.0001
Sensory problems	323	20.3%	147	15.8%	118	26.9%	58	25.7%	<.0001
Sleep disturbance	167	10.5%	70	7.5%	61	13.9%	36	15.9%	<.0001

Figure 2. Adjusted healthcare costs by baseline disability level in the full sample (n = 45,687). The patterned portion of the pharmacy costs indicates costs associated with DMT use.