Influence of Comorbidities on Healthcare Expenditures and Perceived Physical and Mental Health Status Among Adults with Multiple Sclerosis: A Propensity Score-Matched US National-Level Study

Figures & data

Table 1 Distribution of Characteristics Between MS and Non-MS Controls MEPS 2005–2015

		Before Matching						After Matching
		MS		Non-MS				MS		Non-MS
		Unwt. N	Wt.%	Unwt. N	Wt.%	p-value	Sig	Unwt. N	Wt.%	Unwt. N	Wt.%	p-value	Sig
Age group
18–64		470	85.4	165,000	79.9	0.05	*	470	85.4	470	84.4	0.70
65,+		71	14.6	39,230	20.1			71	14.6	71	15.6
Gender
Female		402	73.1	118,000	55.1	0.00	***	402	73.1	402	72.2	0.82
Men		139	26.9	85,807	44.9			139	26.9	139	27.8
Race/Ethnicity
White		366	79.8	104,000	70.8	0.00	**	366	79.8	366	85.1	0.03	*
Other		175	20.2	99,762	29.2			175	20.2	175	14.9
Marital status
Married		303	60.7	108,000	55.6	0.13		303	60.7	271	50.1	0.01	**
Other		238	39.3	95,969	44.4			238	39.3	270	49.9
Education
LT HS		49	9.3	36,911	15.6	0.07		49	9.3	85	12.1	0.58
HS		130	28.0	48,179	28.4			130	28.0	126	28.3
> HS		260	62.7	80,080	56.1			260	62.7	238	59.6
Region
Northeast		103	23.6	33,417	18.7	0.11		103	23.6	109	21.7	0.92
Mid-west		150	24.2	42,190	22.6			150	24.2	122	25.0
South		164	28.9	75,396	36.1			164	28.9	175	30.8
West		124	23.3	52,936	22.6			124	23.3	135	22.6
Poverty status
Poor		100	15.0	33,787	10.8	0.09		100	15.0	71	7.5	0.00	**
Near Poor		110	17.0	42,127	16.4			110	17.0	115	17.2
Middle Income		153	27.9	60,308	29.5			153	27.9	170	30.7
High Income		178	40.1	67,717	43.3			178	40.1	185	44.5
Employment status
Employed		205	40.3	127,000	65.7	0.00	***	205	40.3	347	66.1	0.00	***
Not employed		336	59.7	76,722	34.3			336	59.7	194	33.9
Insurance coverage
Private		338	68.0	130,000	72.5	0.00	***	338	68.0	371	79.0	0.00	***
Public		179	28.4	49,178	18.3			179	28.4	110	13.7
Uninsured		24	3.6	25,169	9.3			24	3.6	60	7.3
Physical health status
Ex/vgood		100	22.2	107,000	57.3	0.00	***	100	22.2	282	57.5	0.00	***
Good		168	28.9	61,937	28.5			168	28.9	164	28.6
Fair/poor		273	48.9	35,083	14.2			273	48.9	95	13.9
Mental health status
Ex/vgood		229	42.2	129,000	66.4	0.00	***	229	42.2	332	65.2	0.00	***
Good		195	38.1	56,072	25.5			195	38.1	157	26.4
Fair/poor		117	19.7	19,267	8.2			117	19.7	52	8.4
BMI status
Under/Normal		204	39.6	67,400	35.2	0.14		204	39.6	205	39.7	0.96
Overweight		324	57.5	132,000	62.9			324	57.5	321	57.7
Obese		13	2.9	4375	1.9			13	2.9	15	2.6
Smoking status
Current smoker		128	23.8	32,217	17.0	0.00	**	128	23.8	79	14.3	0.00	***
Other		373	76.2	155,000	83.0			373	76.2	421	85.7
Pain group
Quite/Extreme		170	30.6	26,077	12.2	0.00	***	170	30.6	52	10.1	0.00	***
Little/Moderate		203	42.2	68,409	36.6			203	42.2	198	38.6
No pain		130	27.2	93,998	51.2			130	27.2	255	51.3
ADL Limitations
Yes		137	24.0	7129	3.0	0.00	***	137	24.0	16	3.3	0.00	***
No		403	76.0	196,000	97.0			403	76.0	523	96.7
IADL Limitations
Yes		188	33.2	13,006	5.6	0.00	***	188	33.2	32	6.0	0.00	***
No		352	66.8	191,000	94.4			352	66.8	509	94.0
Activities disability
Yes		337	61.2	31,945	14.2	0.00	***	337	61.2	85	13.4	0.00	***
No		203	38.8	171,000	85.8			203	38.8	455	86.6
Comorbidities
Anemia		28	5.5	4224	1.7	0.00	***	28	5.5	13	1.8	0.00	**
Anxiety		89	17.1	21,075	11.2	0.01	*	89	17.1	51	8.5	0.00	***
Arthritis		212	42.1	52,100	25.9	0.00	***	212	42.1	155	30.1	0.00	***
Asthma		59	10.5	13,860	6.6	0.04	*	59	10.5	46	9.1	0.55
Cancer		41	8.1	13,858	8.0	0.96		41	8.1	42	9.7	0.43
COPD		80	14.9	22,801	11.5	0.13		80	14.9	68	13.5	0.58
Diabetes		69	12.2	26,604	11.3	0.70		69	12.2	58	8.7	0.07
Eye problems		18	3.7	8430	4.4	0.62		18	3.7	17	4.7	0.49
GERD		60	11.3	15,677	8.3	0.11		60	11.3	50	8.2	0.17
Heart Disease		69	13.2	24,430	12.3	0.67		69	13.2	55	10.7	0.32
Hyperlipidemia		143	25.0	47,146	23.8	0.66		143	25.0	107	20.7	0.16
Hypertension		180	29.5	63,525	29.8	0.90		180	29.5	156	30.7	0.73
Depression		162	29.7	23,331	11.8	0.00	***	162	29.7	72	13.3	0.00	***
Osteoporosis		31	5.7	3654	1.9	0.00	***	31	5.7	12	2.4	0.00	***
Stroke		17	3.1	3880	1.9	0.15		17	3.1	11	2.5	0.54
Thyroid		54	10.8	15,288	8.4	0.24		54	10.8	57	11.5	0.79
Cardio-metabolic		251	41.9	88,259	42.5	0.85		251	41.9	215	41.2	0.86
Respiratory		80	14.9	22,801	11.5	0.13		80	14.9	68	13.5	0.58
Musculo-skeletal		235	46.3	53,919	26.8	0.00	***	235	46.3	159	31.0	0.00	***
Psychiatric		218	41.2	37,093	19.3	0.00	***	218	41.2	104	19.0	0.00	***
Other comorbidities		148	28.8	39,783	20.5	0.00	**	148	28.8	123	23.8	0.11

Notes: Based on 541 adults (age ≥ 18 years) with Multiple Sclerosis (MS) and 203,939 adults without MS before matching; and 541 adults with and without MS after matching. The two groups were matched on age, gender, and race/ethnicity. Asterisks represent statistical significance between the two groups based on chi-square tests. Asterisks represent statistical significance between the two groups based on chi-square tests. ***p< 0.001; **0.001 ≤p< 0.01; *0.01 ≤p<0.05.

Abbreviations: MEPS, Medical Expenditure Panel Survey; Unwt, unweighted; Wt%, weighted percentage; Sig, significant difference; Ex/vgood, excellent or very good; LT HS, less than high school; HS, high school; ADL, activity of daily living; IADL, instrumental activity of daily living; COPD, chronic obstructive pulmonary disease; GERD, gastroesophageal reflux disorder.

Figure 1 Propensity score distribution before matching.

Notes: Multiple sclerosis = 1 denotes the case group (individuals with MS); multiple sclerosis = 2 denotes the control group (individuals without MS).

Figure 2 Propensity score distribution after matching.

Notes: Multiple sclerosis = 1 denotes the case group (individuals with MS); multiple sclerosis = 2 denotes the control group (individuals without MS).

Table 2 Total and Subtypes of Costs Among Any Users (2018 US$)

	MS			Non-MS
	N	Mean	Std Err	N	Mean	Std Err
Total***	541	29,396	1794	541	7875	755
Inpatient	541	4356	883	541	2432	315
ER**	541	718	298	541	226	35
Outpatient**	541	5754	507	541	2749	409
Prescription***	541	15,533	1236	541	1620	152
HHA**	541	1989	344	541	218	70
Other	541	1045	209	541	629	43
Subtypes of costs among Specific Service Users^a
Inpatient	94	23,237	2376	56	25,592	2013
ER	125	3033	1222	88	1555	187
Outpatient**	517	6015	520	473	3060	452
Prescription***	520	16,024	1260	429	2020	176
HHA**	98	12,073	1534	14	7973	1527
Other	356	1506	290	333	955	61

Notes: Based on 541 individuals with MS and 541 matched controls without MS, aged 18 years or older and were alive during particular calendar year. Asterisks represent significant group differences by the presence of MS using t-tests. Asterisks represent statistical significance between the two groups based on chi-square tests. ***p< 0.001; **0.001 ≤p< 0.01. ^aSpecific service user refer to the MEPS respondents in the study sample who reported using any of the specific services such as inpatient, outpatient, home healthcare etc. Type of expenditures among users will not add to average total expenditure because of the denominators.

Abbreviations: Std Err, standard error; ER, emergency room; HHA, Home Health Agency.

Table 3 Unadjusted Total Expenditures by Comorbidities

	MS	Non MS	P-value	Sig	Cost Ratio
Anemia	34,877	17,371	0.06		2.01
Anxiety	28,288	16,738	0.18		1.69
Arthritis	33,700	12,345	0.00	***	2.73
Asthma	36,147	10,079	0.00	***	3.59
Cancer	44,954	22,542	0.02	*	1.99
COPD	31,871	8967	0.00	***	3.55
Diabetes	39,579	17,900	0.01	*	2.21
Eye problems	36,999	16,092	0.02	*	2.30
GERD	48,536	17,106	0.00	***	2.84
Heart disease	40,389	21,148	0.00	***	1.91
Hyperlipidemia	34,430	15,393	0.00	***	2.24
Hypertension	35,924	12,271	0.00	***	2.93
Depression	36,380	17,868	0.00	***	2.04
Osteoporosis	37,002	9926	0.00	***	3.73
Stroke	29,178	48,300	0.37		0.60
Thyroid	37,196	17,401	0.03	*	2.14
Cardio-metabolic	35,164	12,245	0.00	***	2.87
Respiratory	31,871	8967	0.00	***	3.55
Musculoskeletal	32,912	12,174	0.00	***	2.70
Psychiatric	31,692	15,112	0.00	***	2.10
Other comorbidities	40,145	15,782	0.00	***	2.54

Notes: Based on 541 individuals with MS and 541 matched controls without MS, aged 18 years or older and were alive during particular calendar year. Asterisks represent significant group differences by the presence of MS using t-tests. Medical Expenditure Panel Survey 2005–2015. Asterisks represent significant group differences by the presence of MS using t-tests. ***p < 0.001; *0.01 ≤ p < 0.05. Annual mean MS and non-MS costs are presented in 2018 US$.

Abbreviations: COPD, chronic obstructive pulmonary disease; GERD, gastroesophageal reflux disorder.

Table 4 Intercepts and Parameter Estimates for MS vs Non-MS Groups from Separate OLS Regression Analyses on Logged Healthcare Expenditures (2018 US$)

		Beta	SE	Sig	% Diff
Total expenditures
	Intercept	6.634	0.337	***
MS
	Yes	1.532	0.108	***	363
	No	Ref	–
Inpatient expenditures
	Intercept	−0.350	0.601
MS
	Yes	0.545	0.212	*	72
	No	Ref	–
Emergency expenditures
	Intercept	1.359	0.623	*
MS
	Yes	0.259	0.238		30
	No	Ref	–
Outpatient expenditures
	Intercept	4.367	0.545	***
MS
	Yes	0.867	0.154	***	138
	No	Ref	–
Prescription expenditures
	Intercept	2.866	0.614	***
MS
	Yes	2.689	0.199	***	1372
	No	Ref	–
HHA expenditures
	Intercept	−0.162	0.467
MS
	Yes	0.207	0.117		23
	No	Ref	–
Other expenditures
	Intercept	1.366	0.676	*
MS
	Yes	0.215	0.218		24
	No	Ref	–

Notes: Based on 541 individuals with MS and 541 matched controls without MS, aged 18 years or older and were alive during particular calendar year. Medical Expenditure Panel Survey 2005–2015. Asterisks represent statistical significance between the two groups based on chi-square tests. ***p< 0.001; *0.01 ≤p<0.05. OLS regression model included MS and propensity score-matched non-MS group; race/ethnicity; marital status; education; region; poverty status; employment status; health insurance status; physical health status; mental health status; BMI; smoking status; pain; MEPS year; activities of daily living; instrumental activities of daily living; activities disability; anemia; anxiety; arthritis; cancer; COPD; diabetes; eye problems; GERD; heart disease; hyperlipidemia; hypertension; depression; osteoporosis; stroke; and thyroid disorder as independent variables.

Abbreviations: OLS, ordinary least squares; S.E., standard error; Sig, significant difference; COPD, chronic obstructive pulmonary disease; GERD, gastroesophageal reflux disorder. % Diff, Percent difference between MS and propensity score-matched non-MS groups. The percent difference in expenditures between the two groups were calculated using semi-logarithmic equation (e^β – 1).

Table 5 Multinomial Logistic Regression Analysis Physical Health Status

		Good			Fair/Poor
		OR	95% CI	Sig	OR	95% CI	Sig
Multiple Sclerosis
Yes vs No		2.31	[1.50,3.56]	***	4.10	[2.42,6.96]	***
Race/Ethnicity
Others vs White		1.37	[0.79,2.38]		2.51	[1.30,4.83]	**
Marital status
Others vs Married		0.73	[0.40,1.33]		0.50	[0.27,0.95]	*
Education
<High School vs High School		0.97	[0.42,2.26]		1.73	[0.65,4.62]
> High School vs High School		1.20	[0.72,2.01]		0.86	[0.47,1.58]
Region
Mid-west vs Northeast		1.93	[0.95,3.95]		1.20	[0.61,2.39]
South vs Northeast		1.60	[0.85,3.03]		0.78	[0.43,1.41]
West vs Northeast		2.02	[0.92,4.44]		0.77	[0.37,1.59]
Poverty status
Near Poor vs Poor		0.43	[0.19,0.99]	*	0.58	[0.23,1.43]
Middle Income vs Poor		0.65	[0.28,1.52]		0.45	[0.18,1.16]
High Income vs Poor		0.31	[0.12,0.78]	*	0.27	[0.11,0.68]	**
Employment status
Not employed vs Employed		0.96	[0.58,1.60]		1.38	[0.64,2.94]
Insurance coverage
Private vs Uninsured		0.56	[0.24,1.30]		0.28	[0.07,1.06]
Public vs Uninsured		0.79	[0.29,2.14]		0.38	[0.10,1.49]
BMI status
Overweight/Obese vs Under/Normal Weight		1.07	[0.63,1.81]		1.26	[0.67,2.36]
Missing vs Under/Normal Weight		1.17	[0.30,4.61]		0.37	[0.11,1.28]
Smoking status
Current smoker vs Other		2.20	[1.20,4.02]	*	3.14	[1.66,5.94]	***
Pain
Quite/Extreme vs No pain		5.38	[2.28,12.6]	***	18.00	[7.60,42.6]	***
Little/Moderate vs No pain		3.28	[2.28,4.73]	***	7.08	[4.11,12.2]	***
ADL Limitations
Yes vs No		0.65	[0.16,2.71]		0.95	[0.22,4.02]
IADL Limitations
Yes vs No		0.84	[0.21,3.44]		2.14	[0.57,8.03]
Activities disability
Yes vs No		1.39	[0.52,3.71]		3.63	[1.57,8.38]	**
Comorbidities
Anemia
Yes vs No		1.05	[0.36,3.05]		2.80	[0.80,9.78]
Anxiety
Yes vs No		1.89	[0.84,4.25]		2.73	[1.25,5.98]	*
Arthritis
Yes vs No		0.69	[0.38,1.24]		0.60	[0.30,1.23]
Cancer
Yes vs No		1.52	[0.71,3.25]		1.24	[0.51,3.00]
COPD
Yes vs No		1.90	[0.99,3.65]		3.09	[1.62,5.89]	***
Diabetes
Yes vs No		1.90	[0.84,4.31]		2.51	[0.91,6.91]
Eye problems
Yes vs No		0.89	[0.26,2.99]		1.46	[0.28,7.55]
GERD
Yes vs No		3.20	[1.33,7.69]	**	2.57	[0.84,7.89]
Heart disease
Yes vs No		2.57	[1.09,6.06]	*	5.39	[2.16,13.4]	***
Hyperlipidemia
Yes vs No		1.67	[0.95,2.93]		4.10	[1.99,8.44]	***
Hypertension
Yes vs No		1.25	[0.72,2.15]		0.62	[0.35,1.10]
Depression
Yes vs No		3.56	[1.87,6.80]	***	4.81	[2.46,9.42]	***
Osteoporosis
Yes vs No		0.51	[0.25,1.03]		0.45	[0.15,1.33]
Stroke
Yes vs No		0.69	[0.09,5.27]		1.26	[0.22,7.11]
Thyroid disorder
Yes vs No		1.25	[0.70,2.26]		1.39	[0.50,3.88]
MEPS year
2006 vs 2005		0.64	[0.34,1.20]		0.54	[0.27,1.08]
2007 vs 2005		1.04	[0.47,2.32]		0.51	[0.23,1.17]
2008 vs 2005		0.43	[0.21,0.88]	*	0.44	[0.18,1.06]
2009 vs 2005		0.54	[0.24,1.21]		0.37	[0.13,1.04]
2010 vs 2005		0.58	[0.26,1.30]		0.70	[0.27,1.84]
2011 vs 2005		1.02	[0.38,2.76]		0.47	[0.14,1.57]
2012 vs 2005		0.77	[0.23,2.59]		0.50	[0.16,1.62]
2013 vs 2005		0.67	[0.28,1.64]		0.28	[0.11,0.71]	**
2015 vs 2005		1.79	[0.81,3.93]		0.98	[0.32,3.01]

Notes: Based on 541 individuals with MS and 541 matched controls without MS, aged 18 years or older and were alive during particular calendar year. Medical Expenditure Panel Survey 2005–2015. Asterisks represent statistical significance between the two groups based on chi-square tests. ***p< 0.001; **0.001 ≤p< 0.01; *0.01 ≤p<0.05.

Abbreviations: MEPS, Medical Expenditure Panel Survey; OR, odds ratio; CI, confidence interval; Sig, significant difference; BMI, body mass index; ADL, activity of daily living; IADL, instrumental activity of daily living; COPD, chronic obstructive pulmonary disease; GERD, gastroesophageal reflux disorder.

Table 6 Multinomial Logistic Regression Analysis Mental Health Status

		Good			Fair/Poor
		OR	95% CI	Sig	OR	95% CI	Sig
Multiple Sclerosis
Yes vs No		1.42	[1.01,1.99]	*	1.26	[0.58,2.76]
Race/Ethnicity
Others vs White		0.98	[0.54,1.77]		0.95	[0.47,1.91]
Marital status
Others vs Married		0.90	[0.63,1.29]		1.14	[0.60,2.16]
Education
<High School vs High School		2.44	[1.45,4.10]	***	5.77	[2.81,11.8]	***
> High School vs High School		1.21	[0.83,1.75]		1.32	[0.75,2.29]
Region
Mid-west vs Northeast		1.12	[0.73,1.72]		0.58	[0.26,1.27]
South vs Northeast		1.06	[0.67,1.66]		0.70	[0.35,1.39]
West vs Northeast		1.31	[0.81,2.10]		0.78	[0.36,1.71]
Poverty status
Near Poor vs Poor		0.77	[0.39,1.52]		0.76	[0.38,1.55]
Middle Income vs Poor		1.07	[0.54,2.12]		0.71	[0.32,1.58]
High Income vs Poor		0.78	[0.36,1.68]		0.50	[0.21,1.15]
Employment status
Not employed vs Employed		1.49	[0.95,2.33]		1.19	[0.59,2.41]
Insurance coverage
Private vs Uninsured		0.72	[0.37,1.38]		0.66	[0.17,2.55]
Public vs Uninsured		1.06	[0.49,2.30]		0.70	[0.17,2.85]
BMI status
Overweight/Obese vs Under/Normal Weight		1.08	[0.73,1.59]		0.65	[0.37,1.15]
Missing vs Under/Normal Weight		1.01	[0.28,3.63]		0.68	[0.15,3.20]
Smoking status
Current smoker vs Other		1.67	[1.10,2.55]	*	2.52	[1.47,4.34]	***
Pain
Quite/Extreme vs No pain		2.08	[1.19,3.64]	*	2.60	[1.20,5.65]	*
Little/Moderate vs No pain		2.54	[1.72,3.74]	***	2.10	[1.15,3.82]	*
ADL Limitations
Yes vs No		0.45	[0.20,1.01]		0.72	[0.23,2.29]
IADL Limitations
Yes vs No		1.46	[0.70,3.05]		4.52	[1.61,12.7]	**
Activities disability
Yes vs No		1.37	[0.82,2.30]		2.10	[0.97,4.57]
Comorbidities
Anemia
Yes vs No		2.11	[1.05,4.23]	*	0.67	[0.23,1.97]
Anxiety
Yes vs No		1.15	[0.60,2.20]		3.99	[2.13,7.49]	***
Arthritis
Yes vs No		0.64	[0.44,0.93]	*	0.54	[0.30,0.97]	*
Cancer
Yes vs No		0.97	[0.46,2.05]		2.69	[1.03,6.99]	*
COPD
Yes vs No		1.33	[0.81,2.18]		1.65	[0.88,3.09]
Diabetes
Yes vs No		1.33	[0.71,2.50]		2.46	[1.07,5.64]	*
Eye problems
Yes vs No		1.49	[0.54,4.10]		0.11	[0.01,1.02]
GERD
Yes vs No		1.17	[0.51,2.66]		2.42	[0.87,6.72]
Heart disease
Yes vs No		1.31	[0.68,2.55]		0.96	[0.35,2.59]
Hyperlipidemia
Yes vs No		1.50	[0.88,2.56]		2.31	[1.13,4.69]	*
Hypertension
Yes vs No		0.70	[0.47,1.03]		0.37	[0.20,0.66]	***
Depression
Yes vs No		3.32	[2.13,5.16]	***	5.01	[2.69,9.31]	***
Osteoporosis
Yes vs No		0.59	[0.23,1.51]		0.40	[0.10,1.51]
Stroke
Yes vs No		0.50	[0.18,1.42]		1.95	[0.55,6.95]
Thyroid disorder
Yes vs No		0.59	[0.34,1.03]		0.93	[0.41,2.13]
MEPS year
2006 vs 2005		0.68	[0.43,1.08]		0.46	[0.22,0.94]	*
2007 vs 2005		0.60	[0.32,1.13]		0.80	[0.32,1.98]
2008 vs 2005		0.38	[0.22,0.68]	**	0.34	[0.16,0.74]	**
2009 vs 2005		0.74	[0.40,1.40]		0.78	[0.33,1.85]
2010 vs 2005		1.00	[0.51,1.96]		0.49	[0.18,1.36]
2011 vs 2005		1.51	[0.76,2.97]		1.42	[0.53,3.79]
2012 vs 2005		0.73	[0.33,1.62]		0.53	[0.14,1.97]
2013 vs 2005		0.69	[0.36,1.34]		0.51	[0.17,1.50]
2015 vs 2005		0.95	[0.46,1.95]		0.39	[0.12,1.23]

Notes: Based on 541 individuals with MS and 541 matched controls without MS, aged 18 years or older and were alive during particular calendar year. Medical Expenditure Panel Survey 2005–2015. Asterisks represent statistical significance between the two groups based on chi-square tests. ***p< 0.001; **0.001 ≤p< 0.01; *0.01 ≤p<0.05.

Abbreviations: MEPS, Medical Expenditure Panel Survey; OR, odds ratio; CI, confidence interval; Sig, significant difference; BMI, body mass index; ADL, activity of daily living; IADL, instrumental activity of daily living; COPD, chronic obstructive pulmonary disease; GERD, gastroesophageal reflux disorder.