Severe asthma exacerbation rates are increased among female, Black, Hispanic, and younger adult patients: results from the US CHRONICLE study

Figures & data

Table 1. Patient characteristics overall and by sex, race, and ethnicity.

Characteristic^a	All enrolled (N = 1884)	Male (n = 585)	Female (n = 1299)	Non-Hispanic White (n = 1306)	Black (n = 349)	Hispanic (n = 156)
Female sex, %	69	0	100	68	75	71
Age at enrollment, y
n	1879	584	1295	1303	349	156
Mean (SD)	54 (14)	55 (15)	54 (14)	55 (14)	52 (13)	50 (16)
Median	55	57	55	57	54	52
Age at diagnosis, y
n	1811	567	1244	1257	336	150
Mean (SD)	29 (21)	30 (22)	28 (21)	30 (22)	27 (20)	26 (21)
Median	28	30	28	28	27	25
Race, %
White	75	76	75	100	0	71
Black	19	15	20	0	100	4
Other^b	4	6	4	0	0	13
Not reported	2	3	1	0	0	12
Hispanic or Latino ethnicity, %	8	8	9	0	2	100
BMI, kg/m^2
n	1706	523	1183	1165	326	149
Mean (SD)	33 (9)	31 (7)	34 (9)	33 (9)	36 (10)	34 (9)
Median	32	30	33	31	34	32
Residential area, %
Urban	26	26	25	20	33	42
Suburban	50	51	49	52	46	45
Rural	20	17	21	23	16	10
Missing	4	5	4	4	3	3
Employment status, %
Employed full-time	39	47	36	41	32	42
Employed part-time	6	3	7	6	4	5
Self-employed	3	5	2	3	3	2
Homemaker	3	0	4	3	2	5
Full-time student	2	1	2	1	2	2
Retired	22	25	21	25	14	17
Disabled due to asthma	8	6	8	6	16	7
Disabled due to other reasons	7	3	8	5	15	4
Unemployed^c	6	4	7	5	8	10
Missing	4	5	4	4	2	5
Smoking status, %
Never	66	63	68	65	66	78
Former	30	33	28	32	28	19
Current	3	3	4	3	4	2
Living within 500 feet of a major road (e.g. a highway), %
Yes	38	35	39	35	50	36
No	49	52	48	52	39	46
Unknown	11	13	11	11	9	17
Missing	0.6	0.3	0.8	0.9	0	0
Respiratory comorbidities, %
Allergic rhinitis	53	54	52	53	53	54
Seasonal allergies	13	16	13	15	7	17
Perennial allergies	13	13	13	14	10	15
Nasal polyps	8	10	7	8	9	6
COPD	8	10	7	8	7	6
Nonrespiratory comorbidities, %
Hypertension	30	31	30	30	38	21
Hypercholesterolemia	15	18	14	16	14	11
Type 2 diabetes	11	13	11	9	18	14
Depression	16	9	19	17	13	14
Anxiety	14	8	16	15	10	18
Thyroid disease	7	3	9	9	3	5
Enrollment treatment category, %
Biologics	65	69	63	66	59	65
mSCS^d	14	13	14	14	13	13
No biologics or mSCS	30	27	31	29	35	28
Subspecialist care, %
Allergist/immunologist	39	43	38	39	32	47
Pulmonologist	51	48	53	52	58	40
Allergist/immunologist and pulmonologist	10	10	10	9	10	12
Exacerbations in the prior year, %
None	44	48	42	46	42	33
≥1	56	52	58	54	58	67
Daytime symptoms (>2 times/week), %
Yes	54	50	55	52	57	55
No	27	31	25	27	27	30
Unknown	20	19	20	21	16	16
Nocturnal symptoms, %
Yes	39	35	41	37	48	39
No	40	44	39	42	36	44
Unknown	20	21	20	21	16	18
Asthma reliever medication (>2 times per week)
Yes	56	52	57	53	62	58
No	29	33	27	30	25	32
Unknown	16	15	16	17	13	10
Activity limitation due to asthma
Yes	52	47	54	51	56	52
No	29	34	27	29	29	29
Unknown	19	20	19	20	15	19
Subspecialist assessment of asthma control based on GINA Control Assessment, %
Well-controlled	19	23	17	19	18	21
Partly controlled	25	24	25	25	24	29
Uncontrolled	45	42	47	43	52	44
Unknown	11	11	11	13	7	7
ACT Score, %
Very poorly controlled (5–15)	43	42	44	40	52	47
Not well-controlled (16–19)	25	23	26	26	24	21
Well-controlled (20–25)	31	35	30	34	24	32

a Percentages may not sum to 100% as a result of rounding. Missing values rounding to <1% were removed.

b “Other” includes Asian, American Indian or Alaska Native, Native Hawaiian or Other Pacific Islander, and Other.

c “Unemployed” does not include retired, disabled, or homemaker.

d Use of systemic corticosteroids or other systemic immunosuppressants for ≥50% of the prior 12 months. Treatment groups for biologics and mSCS were not mutually exclusive.

ACT, Asthma Control Test; BMI, body mass index; COPD, chronic obstructive pulmonary disease; GINA, Global Initiative for Asthma; mSCS, maintenance systemic corticosteroids.

Figure 1. (A) Biologic recipient at enrollment and (B) insurance status by sex, race/ethnicity, and age. PCP, primary care provider.

Figure 2. Median FEV₁ (A) and FVC (B) percent predicted by sex, race/ethnicity, and age. Error bars denote interquartile range. FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity.

Figure 3. Highest median BEC^a by sex, race/ethnicity, and age. ^aHighest BEC while not receiving biologics or SCS. Error bars denote interquartile range. BEC, blood eosinophil count; SCS, systemic corticosteroids.

Figure 4. Rates of HCP-confirmed asthma (A) exacerbations, (B) emergency department visits, and (C) hospitalizations by sex, race/ethnicity, and age. *P < 0.05; Error bars denote 95% CI. CI, confidence interval; HCP, health care provider.

Figure 5. Mean (A) ACT and (B) SGRQ scores by sex, race/ethnicity, and age. *P < 0.05; Error bars denote standard deviation. ACT scores range from 5 to 25 with higher scores reflecting better asthma control. SGRQ scores range from 1 to 100, with higher scores indicating poorer HRQoL. ACT, Asthma Control Test; HRQoL, health-related quality of life; SGRQ, St. George’s Respiratory Questionnaire.

Table 2. Patient and clinical characteristics by age at enrollment and age at diagnosis.

Characteristic^a	Age at enrollment 18–49 y (n = 628)	Age at enrollment 50–64 y (n = 805)	Age at enrollment ≥65 y (n = 446)	Age at diagnosis <12 y (n = 567)	Age at diagnosis 12–17 y (n = 113)	Age at diagnosis 18–40 y (n = 546)	Age at diagnosis >40 y (n = 585)
Sex, %
Male	29	31	35	32	31	27	35
Female	71	69	65	68	69	73	66
Age at enrollment, y
n	628	805	446	566	112	544	584
Mean (SD)	38 (9)	57 (4)	72 (5)	48 (16)	51 (15)	51 (12)	63 (10)
Median	40	57	71	50	51	52	63
Age at diagnosis, y
n	603	772	431	567	113	546	585
Mean (SD)	17 (14)	30 (19)	42 (24)	5 (3)	14 (2)	30 (7)	54 (9)
Median	14	33	49	5	14	30	52
Race, %
White	72	73	84	74	83	75	76
Black	20	22	11	20	14	19	17
Other^b	6	4	4	5	0.9	3	5
Not reported	3	1	2	1	0	3	2
Missing	0	0.1	0	0.2	2	0	0
Hispanic/Latino ethnicity, %	11	8	6	10	10	8	7
BMI, kg/m^2
n	573	718	412	513	96	491	540
Mean (SD)	34 (10)	34 (9)	31 (7)	33 (9)	33 (9)	34 (9)	33 (8)
Median (range)	33	32	30	32	32	33	31
Residential area, %
Urban	29	23	25	28	24	27	22
Suburban	49	51	50	52	55	50	48
Rural	18	21	21	17	17	19	24
Missing	3	4	4	3	4	3	5
Employment status, %
Employed full-time	54	44	12	44	44	46	30
Employed part-time	7	4	7	8	7	5	5
Self-employed	3	4	2	3	4	3	3
Homemaker	4	3	2	2	4	3	2
Full-time student	4	0.4	0	4	0	0.7	0.5
Retired	0.5	14	68	15	18	14	38
Disabled due to asthma	8	11	2	7	4	9	7
Disabled due to other reasons	6	10	1	6	10	7	6
Unemployed^c	10	6	0.4	7	4	7	3
Missing	5	3	5	3	4	3	5
Smoking status, %
Never	71	66	60	72	71	68	58
Former	23	30	39	24	26	28	38
Current	5	3	0.9	3	3	3	3
Living within 500 feet of a major road (e.g. highway)
Yes	40	38	36	40	40	40	36
No	48	49	52	51	51	49	50
Unknown	12	12	10	8	6	10	14
Missing	0.5	0.7	0.7	0.9	2	0.2	0.7
Respiratory comorbidities, %
Allergic rhinitis	57	53	48	57	57	54	51
Seasonal allergies	15	13	12	15	20	15	10
Perennial allergies	14	13	12	17	16	14	9
Nasal polyps	12	7	3	6	8	14	5
COPD	4	8	14	6	10	7	11
Nonrespiratory comorbidities, %
Hypertension	17	33	43	28	29	29	34
Hypercholesterolemia	6	18	24	13	14	13	20
Type 2 diabetes	5	15	13	10	13	11	11
Depression	15	17	16	15	17	17	16
Anxiety	16	13	13	16	11	13	13
Thyroid disease	4	8	10	6	10	7	9
Enrollment treatment category, %
Biologics	65	66	62	67	61	67	63
mSCS^d	14	13	14	12	16	16	13
No biologics or mSCS	30	28	33	28	32	27	33
Subspecialist care, %
Allergist/immunologist	45	37	34	44	44	43	31
Pulmonologist	47	52	57	45	48	47	60
Allergist/immunologist and pulmonologist	8	11	10	10	8	11	8
Exacerbations in the prior year, %
None	41	44	50	46	41	44	44
≥1	59	57	50	55	59	56	56
Daytime symptoms (>2 times per week), %
Yes	57	54	48	58	57	52	52
No	24	27	32	25	26	28	29
Unknown	19	19	20	17	18	20	19
Nocturnal symptoms, %
Yes	43	39	35	42	38	38	39
No	37	41	45	40	40	41	42
Unknown	20	20	21	18	22	21	19
Asthma reliever medication (>2 times per week)
Yes	60	56	50	60	51	56	53
No	26	29	33	26	31	28	33
Unknown	15	16	17	14	18	17	15
Activity limitation due to asthma
Yes	52	53	50	51	52	49	56
No	29	29	30	30	27	32	26
Unknown	20	18	20	19	21	19	18
Subspecialist assessment of asthma control based on GINA Control Assessment, %
Well-controlled	17	20	20	19	20	20	18
Partly controlled	26	23	27	24	21	25	26
Uncontrolled	47	47	40	48	45	44	45
Unknown	10	10	14	10	13	11	11
ACT Score, %
Very poorly controlled (5–15)	44	44	40	45	39	45	40
Not well-controlled (16–19)	27	23	26	26	24	24	25
Well-controlled (20–25)	29	33	33	29	37	31	35

a Percentages may not sum to 100% as a result of rounding. Missing values rounding to <1% were removed. Age at enrollment data were missing for five patients. Age at diagnosis data were missing for 73 patients.

b “Other” includes Asian, American Indian or Alaska Native, Native Hawaiian or Other Pacific Islander, and Other.

c “Unemployed” does not include retired, disabled, or homemaker.

d Use of systemic corticosteroids or other systemic immunosuppressants for ≥50% of the prior 12 months. Treatment groups for biologics and mSCS were not mutually exclusive.

ACT, Asthma Control Test; BMI, body mass index; COPD, chronic obstructive pulmonary disease; GINA, Global Initiative for Asthma; mSCS, maintenance systemic corticosteroids.

Data availability statement

CHRONICLE is an ongoing study; individual de-identified participant data cannot be shared until the study concludes. The full study protocol is available upon request of the corresponding author. Individuals who were or were not involved in the study may submit publication proposals to the study’s Publication Steering Committee by contacting the corresponding author.