Table 2.

Prevalence of Self-Reported Adverse Respiratory Symptoms: Past 30-Day E-Cigarette Users (N=2448) and Non-Users (N=7783)

	Connecticut Adolescents		Northern California Adolescents		Southern California Young Adults: CHS¹		Southern California Young Adults: HH²
	E-Cigarette Use^3,4		E-Cigarette Use^3,4		E-Cigarette Use^3,4		E-Cigarette Use^3,4
	Yes N=1447	No N=3420	Yes N=302	No N=1120	Yes N=195	No N=1213	Yes N=504	No N=2030
Bronchitis Symptoms ^5,6
Usually seem congested in the chest	16.3	10.9	14.3	10.6	27.7	16.2	15.2	10.7
Persistent cough upon waking (past 12 months)	9.0	6.3	--⁷	--⁷	9.7	5.0	4.3	2.9
Persistent cough other times (past 12 months)	13.5	9.2	--⁷	--⁷	13.3	6.4	4.5	3.8
Heavy coughing (past 30 days)	--⁷	--⁷	32.6	20.4	--⁷	--⁷	--⁷	--⁷
Had bronchitis (past 12 months)	4.7	3.4	--⁷	--⁷	9.2	4.6	4.9	3.7
Bronchitis composite: ≥1 of the above	27.2	21.5	37.2	26.7	37.4	22.8	19.3	15.5
Asthma Symptoms ^5,6
Ever doctor diagnosed asthma	21.7	23.3	20.5	19.4	28.4	23.4	22.9	22.2
Asthma episode or attack (past 12 months)	--⁷	--⁷	6.7	6.1	--⁷	--⁷	--⁷	--⁷
Emergency/urgent care for asthma (past 12 months)	--⁷	--⁷	1.0	2.6	--⁷	--⁷	--⁷	--⁷
Hospital overnight for asthma (past 12 months)	--⁷	--⁷	1.0	1.0	--⁷	--⁷	--⁷	--⁷
Medication for asthma or wheeze (past 12 months)	11.2	10.7	15.8	15.7	9.8	8.2	8.0	8.0
Asthma attack (past 30 days)	--⁷	--⁷	3.5	2.8	--⁷	--⁷	--⁷	--⁷
Wheezing or whistling (ever)	26.2	21.4	--⁷	--⁷	48.7	29.0	27.2	26.3
Wheezing or whistling (past 12 months)	20.1	12.0	--⁷	--⁷	28.7	12.4	15.7	12.4
Asthma composite: ≥1 of the above⁸	23.8	16.0	19.3	18.1	29.4	15.2	20.1	15.5
Shortness of Breath ^5,6
Tire easily when physically active	--⁷	--⁷	25.7	18.9	--⁷	--⁷	--⁷	--⁷
Shortness of breath when hurrying or walking uphill	25.8	18.4			15.9	17.1	23.6	19.8
Ever stop for breath when walking on level ground⁹	6.6	3.4	--⁷	--⁷	2.6	1.8	3.6	3.8
Ever stop for breath when walking 100 yards⁹	6.1	3.4	--⁷	--⁷	2.6	1.6	2.4	3.2
Too short of breath to leave house or when dressing⁹	3.3	1.4	--⁷	--⁷	1.0	1.0	1.5	1.7
`Walk slower on level ground due to shortness of breath⁹	5.2	3.7	--⁷	--⁷	6.2	4.1	5.6	5.9
Shortness of breath composite: ≥1 of the above	25.8	18.4	25.7	18.9	15.9	17.1	23.6	19.8

^1.

Children’s Health Study

^2.

Happiness and Health Study

^3.

Yes indicates use of e-cigarettes ≥1 day in the past 30 days; No indicates no use in the past 30 days

^4.

Sample size may be less than the total for some respiratory outcomes due to missing data

^5.

All values report as percent

^6.

Bold text in table cells indicates statistically significant (P<0.05) difference in prevalence of the respiratory outcome between past 30-day e-cigarette users and non-users, calculated separately for each study (chi-square test)

^7.

Survey item not included in the study questionnaire

^8.

Excludes ever doctor diagnosed asthma and ever wheezing or whistling

^9.

Items only asked of those who reported shortness of breath when hurrying or walking uphill