Health-Related Quality of Life and Health Utilities of Mild, Moderate, and Severe Asthma: Evidence from the Medical Expenditure Panel Survey

Figures & data

Table 1 Baseline Characteristics of Patients without Asthma and Patients with Asthma by Severity, 2010–2016^a

	No Asthma (n = 135,397)	Total Asthma (n = 10,222)	Mild Asthma (n = 7704)	Moderate Asthma (n = 2438)	Severe Asthma (n = 80)	P-value^b
National estimates, N (%)	1,418,534,135	105,740,815	78,021,972	26,630,773	1,088,070
Age (years), mean (SE)	49.1 (0.2)	49.7 (0.4)	48.0 (0.4)	54.5 (0.6)	59.4 (2.0)	<0.001
18–34	36,566 (27.0%)	2492 (24.4%)	2150 (27.9%)	339 (13.9%)	3 (3.8%)	<0.001
35–64	71,068 (52.5%)	5496 (53.8%)	4060 (52.7%)	1388 (56.9%)	48 (60.0%)
≥65	27,763 (20.5%)	2234 (21.9%)	1494 (19.4%)	711 (29.2%)	29 (36.3%)
Sex						<0.001
Male	58,750 (43.4%)	3300 (32.3%)	2466 (32.0%)	817 (33.5%)	17 (21.3%)
Female	76,647 (56.6%)	6922 (67.7%)	5238 (68.0%)	1621 (66.5%)	63 (78.8%)
Race						<0.001
White	94,434 (69.7%)	6702 (65.6%)	4976 (64.6%)	1671 (68.5%)	55 (68.8%)
Black	26,743 (19.8%)	2527 (24.7%)	1970 (25.6%)	538 (22.1%)	19 (23.8%)
Other^c	1133 (0.8%)	120 (1.2%)	92 (1.2%)	28 (1.1%)	0 (0%)
Hispanic						<0.001
Yes	32,496 (24.0%)	2002 (19.6%)	1624 (21.1%)	375 (15.4%)	3 (3.8%)
No	102,901 (76.0%)	8220 (80.4%)	6080 (78.9%)	2063 (84.6%)	77 (96.3%)
Region						<0.001
Northwest	22,098 (16.3%)	2144 (21.0%)	1588 (20.6%)	540 (22.1%)	16 (20.0%)
Midwest	27,601 (20.4%)	2183 (21.4%)	1617 (21.0%)	550 (22.6%)	16 (20.0%)
South	49,931 (36.9%)	3469 (33.9%)	2571 (33.4%)	858 (35.2%)	40 (50.0%)
West	35,767 (26.4%)	2426 (23.7%)	1928 (25.0%)	490 (20.1%)	8 (10.0%)
Marital status						<0.001
Married	67,425 (49.8%)	4154 (40.6%)	3040 (39.5%)	1078 (44.2%)	36 (45.0%)
Widowed	10,019 (7.4%)	970 (9.5%)	671 (8.7%)	290 (11.9%)	9 (11.3%)
Divorced/separated	21,148 (15.6%)	2075 (20.3%)	1529 (19.8%)	527 (21.6%)	19 (23.8%)
Not married	36,804 (27.2%)	3023 (29.6%)	2464 (32.0%)	543 (22.3%)	16 (20.0%)
Education						<0.001
Less than high school diploma	25,640 (18.9%)	2182 (21.3%)	1689 (21.9%)	484 (19.9%)	9 (11.3%)
High school diploma	36,133 (26.7%)	2647 (25.9%)	1973 (25.6%)	649 (26.6%)	25 (31.3%)
Bachelor’s degree	50,525 (37.3%)	3765 (36.8%)	2808 (36.4%)	920 (37.7%)	37 (46.3%)
Advanced degree	11,645 (8.6%)	837 (8.2%)	603 (7.8%)	227 (9.3%)	7 (8.8%)
Unknown	11,454 (8.5%)	791 (7.7%)	631 (8.2%)	158 (6.5%)	2 (2.5%)
Income level						<0.001
≤0	3487 (2.6%)	349 (3.4%)	280 (3.6%)	64 (2.6%)	5 (6.3%)
> 0–20,000	28,397 (21.0%)	2963 (29.0%)	2270 (29.5%)	673 (27.6%)	20 (25.0%)
>20,000–40,000	29,915 (22.1%)	2230 (21.8%)	1692 (22.0%)	519 (21.3%)	19 (23.8%)
>40,000–80,000	37,217 (27.5%)	2446 (23.9%)	1838 (23.9%)	592 (24.3%)	16 (20.0%)
>80,000	36,381 (26.9%)	2234 (21.9%)	1624 (21.1%)	590 (24.2%)	20 (25.0%)
Insurance						<0.001
Any private	80,708 (59.6%)	5378 (52.6%)	3958 (51.4%)	1367 (56.1%)	53 (66.3%)
Public only	36,337 (26.8%)	4000 (39.1%)	3017 (39.2%)	957 (39.3%)	26 (32.5%)
Uninsured	18,352 (13.6%)	844 (8.3%)	729 (9.5%)	114 (4.7%)	1 (1.3%)
Smoking status						<0.001
Yes	20,818 (15.4%)	1893 (18.5%)	1474 (19.1%)	409 (16.8%)	10 (12.5%)
No	101,529 (75.0%)	7389 (72.3%)	5484 (71.2%)	1839 (75.4%)	66 (82.5%)
Unknown	13,050 (9.6%)	940 (9.2%)	746 (9.7%)	190 (7.8%)	4 (5.0%)
ED visits	24,332 (18.0%)	2993 (29.3%)	2252 (29.2%)	714 (29.3%)	27 (33.8%)	<0.001
Hospitalizations	13,249 (9.8%)	1547 (15.1%)	1074 (13.9%)	458 (18.8%)	15 (18.8%)	<0.001
CCI, mean (SE)^d	0.51 (0.01)	0.74 (0.02)	0.70 (0.03)	0.85 (0.04)	1.29 (0.31)	<0.001

Notes: ^aData were presented as the number of patients (percentage). ^bStatistical significance was compared between patients with mild, moderate, severe asthma with a 2-sided P < 0.05 using Rao-Scott Chi-square test and ANOVA. ^cOther includes American Indian, Alaska Native, Asian, Native Hawaiian, Pacific Islander, and multiple races. ^dCharlson Comorbidity Index includes myocardial infarction, heart failure, peripheral vascular disease, dementia, cerebrovascular disease, connective tissue disease, ulcer disease mild liver disease hemiplegia, moderate or severe renal disease, diabetes, tumor, moderate or severe liver, and metastatic solid tumor.

Abbreviations: SE, standard error; CCI, charlson comorbidity index.

Figure 1 Low quality of life in perceived health status for patients without asthma and for patients with asthma by severity, 2010–2016 ^aThe percentage of low quality of life defined as the percentage of persons who answered fair or poor for the question of perceived overall and mental health and the percentage of persons who reported physical limitation by severity of asthma. ^bStatistical significance was compared between patients with mild, moderate, severe asthma with a 2-sided P < 0.05 using Rao-Scott chi-square test.

Table 2 SF-12 Physical and Mental Health Summary Scores of Patients without Asthma and Patients with Asthma by Severity, 2010–2016

	No Asthma (n = 123,455)		Total Asthma (n = 9388)		Mild (n=7042)		Moderate (n=2274)		Severe (n=77)		P-value^a
	Mean	(SE)	Mean	(SE)	Mean	(SE)	Mean	(SE)	Mean	(SE)
SF-12, PCS
Total	48.5	(0.1)	43.2	(0.3)	43.9	(0.3)	41.6	(0.5)	35.9	(1.3)	<0.001
Sex
Men	49.0	(0.1)	44.8	(0.4)	45.4	(0.4)	43.5	(0.7)	37.6	(2.9)	<0.001
Women	48.1	(0.1)	42.4	(0.3)	43.2	(0.3)	40.5	(0.6)	35.4	(1.4)	<0.001
Age (years)
18–34	53.2	(0.1)	50.2	(0.4)	50.3	(0.4)	49.4	(1.0)	51.4	(0.6)	<0.001
35–64	48.7	(0.1)	42.7	(0.3)	42.9	(0.4)	42.5	(0.5)	33.9	(1.5)	<0.001
≥65	42.1	(0.2)	36.6	(0.5)	36.8	(0.5)	36.2	(0.9)	36.8	(1.7)	<0.001
Race
White	48.6	(0.1)	43.3	(0.3)	44.0	(0.3)	41.7	(0.5)	36.1	(1.3)	<0.001
Black	47.2	(0.2)	42.6	(0.4)	43.5	(0.4)	39.7	(0.8)	34.2	(4.0)	<0.001
Other^b	49.5	(0.2)	43.6	(1.0)	44.1	(1.2)	42.1	(1.2)	35.6	(3.3)	<0.001
Smoking
Yes	46.5	(0.1)	39.7	(0.6)	40.6	(0.6)	36.9	(1.0)	34.7	(4.2)	<0.001
No	48.9	(0.1)	44.1	(0.3)	44.8	(0.3)	42.7	(0.5)	36.0	(1.4)	<0.001
SF-12, MCS
Total	51.0	(0.1)	48.4	(0.2)	48.2	(0.2)	49.2	(0.3)	47.1	(2.0)	<0.001
Sex
Men	51.8	(0.1)	49.5	(0.3)	49.2	(0.3)	50.4	(0.6)	46.0	(3.3)	<0.001
Women	50.3	(0.1)	47.9	(0.2)	47.7	(0.3)	48.6	(0.4)	47.4	(2.4)	<0.001
Age (years)
18–34	49.9	(0.1)	48.2	(0.4)	48.3	(0.5)	48.0	(1.1)	52.7	(0.8)	<0.001
35–64	50.5	(0.1)	47.2	(0.3)	47.0	(0.3)	47.8	(0.5)	47.0	(2.9)	<0.001
≥65	52.4	(0.1)	50.7	(0.4)	50.2	(0.5)	51.8	(0.5)	46.6	(3.1)	<0.001
Race
White	51.0	(0.1)	50.8	(0.5)	48.2	(0.3)	49.4	(0.4)	47.0	(2.4)	<0.001
Black	50.9	(0.1)	48.3	(0.3)	48.7	(0.3)	47.1	(0.9)	46.4	(3.6)	<0.001
Other^b	51.7	(0.2)	48.2	(0.6)	47.8	(0.6)	49.5	(1.3)	48.2	(0.6)	<0.001
Smoking
Yes	47.6	(0.1)	44.3	(0.5)	44.3	(0.5)	44.3	(1.0)	48.8	(4.2)	<0.001
No	51.6	(0.1)	49.5	(0.2)	49.2	(0.2)	50.3	(0.3)	46.9	(2.2)	<0.001

Notes: ^aStatistical significance was compared between patients with mild, moderate, severe asthma with a 2-sided P < 0.05 using ANOVA. ^bOther includes American Indian, Alaska Native, Asian, Native Hawaiian, Pacific Islander, and multiple races.

Abbreviations: SF-12v2, 12-Item short form health survey version 2; PCS, physical component summary; MCS, mental component summary; SE, standard error.

Table 3 Multivariable Survey Regression Analysis to Estimate the SF-12 PCS and MCS of Asthma Patients by Severity, 2010–2016

	SF-12 PCS			SF-12 MCS
	Coefficient	SE	P-value	Coefficient	SE	P-value
Asthma severity (ref: mild asthma)
Moderate	−0.966	0.381	0.012	0.459	0.399	0.252
Severe	−5.273	1.344	<0.001	−1.875	1.837	0.309
ED visits	−2.637	1.344	<0.001	−1.987	0.406	<0.001
Hospitalizations	−3.605	0.566	<0.001	−1.518	0.491	0.002
Age (years) (ref: 18–34)
35–64	−6.049	0.398	<0.001	−0.940	0.454	0.040
≥65	−8.446	0.630	<0.001	4.041	0.601	<0.001
Sex (ref: male)
Female	−1.076	0.359	0.003	−0.883	0.374	0.019
Race (ref: White)
Black	1.364	0.371	<0.001	2.342	0.399	<0.001
Other^a	−0.350	0.741	0.638	−0.287	0.545	0.600
Hispanic (ref: no)
Yes	1.385	0.447	0.002	0.724	0.443	0.104
Region (ref: northwest)
Midwest	−2.164	0.552	<0.001	−0.302	0.514	0.558
South	−2.046	0.526	<0.001	−0.634	0.480	0.188
West	−1.733	0.569	0.003	−0.730	0.541	0.179
Marital status (ref: not married)
Married	−0.383	0.669	0.568	−0.179	0.626	0.776
Widowed	0.830	0.524	0.115	−1.609	0.545	0.004
Divorced/separated	1.873	0.485	<0.001	−0.395	0.511	0.440
Education (ref: advanced degree)
Less than high school diploma	−4.186	0.727	<0.001	−1.357	0.592	0.023
High school graduate	−3.540	0.667	<0.001	0.238	0.619	0.701
Bachelor’s degree	−2.470	0.531	<0.001	−0.165	0.567	0.771
Income level (ref: >80,000)
≤20,000	−5.011	0.532	<0.001	−3.893	0.565	<0.001
>20,000–40,000	−3.303	0.496	<0.001	−2.612	0.529	<0.001
>40,000–80,000	−2.098	0.426	<0.001	−0.740	0.440	0.094
Insurance (ref: uninsured)
Any private	1.168	0.697	0.095	2.937	0.828	0.001
Public only	−3.817	0.755	<0.001	−0.863	0.887	0.332
Smoking	−1.512	0.498	0.003	−2.037	0.514	<0.001
CCI^b	−1.831	0.150	<0.001	−0.689	0.138	<0.001
Intercept	58.605	1.020	<0.001	50.978	1.097	<0.001

Notes: ^aOther includes American Indian, Alaska Native, Asian, Native Hawaiian, Pacific Islander, and multiple races. ^bCharlson Comorbidity Index includes myocardial infarction, heart failure, peripheral vascular disease, dementia, cerebrovascular disease, connective tissue disease, ulcer disease mild liver disease hemiplegia, moderate or severe renal disease, diabetes, tumor, moderate or severe liver, and metastatic solid tumor.

Abbreviations: SF-6D, short-form six-dimension; PCS, physical component summary; MCS, mental component summary; SE, standard error; ED, emergency department; CCI, charlson comorbidity index.

Table 4 SF-6D Scores of Patients without Asthma and Patients with Asthma by Severity, 2010–2016

	No Asthma (n = 123,391)		Total Asthma (n = 9387)		Mild (n = 7037)		Moderate (n = 2273)		Severe (n = 77)		P-value^a
	Mean	(SE)	Mean	(SE)	Mean	(SE)	Mean	(SE)	Mean	(SE)
Total	0.794	(0.001)	0.728	(0.003)	0.731	(0.003)	0.723	(0.005)	0.659	(0.023)	<0.001
Sex
Men	0.807	(0.001)	0.753	(0.005)	0.755	(0.006)	0.751	(0.009)	0.665	(0.042)	<0.001
Women	0.783	(0.001)	0.716	(0.004)	0.719	(0.004)	0.708	(0.006)	0.658	(0.027)	<0.001
Age (years)
18–34	0.816	(0.001)	0.777	(0.005)	0.778	(0.005)	0.769	(0.014)	0.830	(0.007)	<0.001
35–64	0.791	(0.001)	0.713	(0.004)	0.713	(0.005)	0.716	(0.007)	0.641	(0.033)	<0.001
≥65	0.760	(0.002)	0.701	(0.006)	0.698	(0.007)	0.708	(0.009)	0.663	(0.030)	<0.001
Race
White	0.794	(0.001)	0.730	(0.004)	0.732	(0.004)	0.726	(0.006)	0.660	(0.026)	<0.001
Black	0.782	(0.002)	0.722	(0.005)	0.732	(0.005)	0.688	(0.012)	0.638	(0.054)	<0.001
Other	0.808	(0.003)	0.729	(0.011)	0.729	(0.013)	0.730	(0.016)	0.668	(0.032)	<0.001
Smoking
Yes	0.747	(0.002)	0.661	(0.007)	0.668	(0.007)	0.640	(0.012)	0.665	(0.034)	<0.001
No	0.803	(0.001)	0.745	(0.003)	0.747	(0.003)	0.743	(0.005)	0.658	(0.027)	<0.001

Notes: ^aStatistical significance was compared between patients with mild, moderate, severe asthma with a 2-sided P < 0.05 using ANOVA.

Abbreviations: SF-6D, short-form six-dimension; SE, standard error.

Table 5 Multivariable Survey Regression Analysis to Estimate the SF-6D of Asthma Patients by Severity, 2010–2016

	SF-6D
	Coefficient	SE	P-value
Asthma severity (ref: mild asthma)
Moderate	−0.003	0.005	0.482
Severe	−0.059	0.017	0.001
ED visits	−0.039	0.005	<0.001
Hospitalizations	−0.042	0.007	<0.001
Age (years) (ref: 18–34)
35–64	−0.054	0.005	<0.001
≥65	−0.023	0.008	0.003
Sex (ref: male)
Female	−0.020	0.005	<0.001
Race (ref: White)
Black	0.033	0.005	<0.001
Other^a	−0.006	0.008	0.492
Hispanic (ref: no)
Yes	0.018	0.006	0.001
Region (ref: northwest)
Midwest	−0.020	0.007	0.005
South	−0.022	0.007	0.001
West	−0.021	0.007	0.006
Marital status (ref: not married)
Married	−0.004	0.088	0.630
Widowed	−0.009	0.007	0.202
Divorced/separated	0.010	0.006	0.107
Education (ref: advanced degree)
Less than high school diploma	−0.046	0.008	<0.001
High school graduate	−0.025	0.008	0.001
Bachelor’s degree	−0.021	0.007	0.002
Income level (ref: >80,000)
≤20,000	−0.076	0.007	<0.001
>20,000–40,000	−0.050	0.006	<0.001
>40,000–80,000	−0.023	0.005	<0.001
Insurance (ref: uninsured)
Any private	0.037	0.009	<0.001
Public only	−0.038	0.010	<0.001
Smoking	−0.031	0.007	<0.001
CCI^b	−0.021	0.002	<0.001
Intercept	0.872	0.013	<0.001

Notes: ^aOther includes American Indian, Alaska Native, Asian, Native Hawaiian, Pacific Islander, and multiple races. ^bCharlson Comorbidity Index includes myocardial infarction, heart failure, peripheral vascular disease, dementia, cerebrovascular disease, connective tissue disease, ulcer disease mild liver disease hemiplegia, moderate or severe renal disease, diabetes, tumor, moderate or severe liver, and metastatic solid tumor.

Abbreviations, SF-6D, short-form six-dimension; PCS, physical component summary; MCS, mental component summary; SE, standard error; ED, emergency department; CCI, charlson comorbidity index.