Long-term effects of asthma medication on asthma symptoms: an application of the targeted maximum likelihood estimation

Table 3 Characteristics of the study participants at the three time points ISAAC II, SOLAR I and SOLAR II (N = 121)

Variables	ISAAC II	SOLAR I	SOLAR II
Age, mean (sd^a)	9.6 (0.56)	17.0 (0.59)	22.3 (0.69)
NAs	0	0	0
Asthma symptoms, N (%)
Yes	116 (95.9)	80 (66.1)	79 (65.3)
NAs^b	0	2 (1.7)	1 (0.8)
Control medication, N (%)
Yes	67 (55.4)	18 (14.9)	n.m.^c
NAs	11 (9.1)	4 (3.3)
Only reliever medication
Yes	19 (15.7)	30 (24.8)	n.m.
NAs	11 (9.1)	4 (3.3)
No asthma medication intake at all
Yes	24 (19.8)	69 (57.0)	n.m.
NAs	11 (9.1)	4 (3.3)
Study center, N (%)
Munich	68 (56.2)
NAs	0
Sex
Male	80 (66.1)
NAs	0
SES^d parents, N (%)
High	63 (52.1)
NAs	1 (0.8)
Asthma history of parents^e, N (%)
Yes	25 (20.7)
NAs	13 (10.7)
Passive smoking^f, N (%)
Yes	32 (26.4)	58 (47.9)	55 (45.5)
NAs	3 (2.5)	1 (0.8)	1 (0.8)
Current smoker^g, N (%)
Yes	n.m.	38 (31.4)	46 (38.0)
NAs		0	0
Physical activity^h, N (%)
Yes	n.m.	96 (79.3)	72 (59.5)
NAs		1 (0.8)	0
Overweightⁱ
yes	n.m.	11 (9.1)	28 (23.1)
NAs		2 (1.7)	0
Current hay fever^j, N (%)
Yes	32 (26.4)	37 (30.6)	33 (27.3)
NAs	0	1 (0.8)	1 (0.8)

Abbreviations and comments. ^aSd standard deviation, ^bNAs missing values, ^cn.m. not measured, ^dSES socio-economic status (high if one parent has at least higher secondary education or university degree); ^eYes if at least one parent has ever had asthma; ^fISAAC II: passive smoking of child if parents are current smokers, SOLAR I/SOLAR II: Yes if exposition to passive smoke per day > 0,5 h; ^gCurrent smoker = smoked ever for 1 year and smoked in the last month; ^hYes if participant reports doing sport at least once per week; ⁱYes if body mass index > = 25; ^jYes if ever diagnosed hay fever by a doctor and itchy eyes and runny nose without cold in the last 12 months

ISSN: 1471-2288