Common use of Study Population Clause in Contracts

Study Population. 490 schools from the canton of Zurich were invited and 37 participated. 3870 children aged 6-17 years took part. For 3079 we had questionnaires with information on wheeze and exertional wheeze from both parents and children (Table 1). FeNO results were available for 2762 children (median 12ppb, interquartile range [IQR] 7-21) and FVC measurements for 2217 (median 87%, IQR 82-91). Most questionnaires were completed by the mothers (n=1765, 57%). 667 children (22%) helped their parents to complete the questionnaire. Parents of 425 children (14%) had a history of asthma. Table 1: Sociodemographic characteristics of schoolchildren in the ▇▇▇▇ study (N=3079). n (%) Male sex 1519 (49) Age in years, median (range) 12.3 (6.0-17.2) Who answered the parental questionnaire Mother alone 1765 (57) Father alone 406 (13) Mother and father 202 (7) One or both parents and the child 667 (22) Other 28 (1) Child born in Switzerland 2726 (89) Mother born in Switzerland 1764 (58) Father born in Switzerland 1859 (60) Number of children per household One or two 2073 (67) More than two 926 (30) Urbanisation degree Large urban area 1338 (44)