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Original article

Vol. 151 No. 3132 (2021)

LuftiBus in the school (LUIS): a population-based study on respiratory health in schoolchildren

Cite this as:
Swiss Med Wkly. 2021;151:w20544


Respiratory disease is common in children and strongly associated with lifestyle and environmental exposures. Thus, it is important to study the epidemiology locally. The LuftiBus in the School (LUIS) study was set up to assess the respiratory health of schoolchildren in the canton of Zurich, Switzerland.

LUIS is a cross-sectional population-based study that was carried out 2013 to 2016. Children aged 6–17 years living in the canton of Zurich were eligible to participate. All schools in the canton were approached and the school head decided whether the school would participate and with which classes. Consenting parents answered a standardised questionnaire at home and assenting children completed a shorter questionnaire by interview at school. Trained technicians measured children’s lung function, including spirometry, double tracer gas single-breath washout (DTG-SBW) and fractional exhaled nitric oxide (FeNO). Address histories of participants were geocoded to be linked with area-based socioeconomic measures and environmental exposures such as spatiotemporal air pollution estimates for specific time periods and locations. A subgroup was seen again 12 months later using the same procedures to collect longitudinal data.

The study included 3870 children at baseline and 655 at the 1-year follow-up. Median age was 12.7 years; 281 (8%) had wheezed in the past year. At baseline we collected 3457 (89%) parental and 3546 (92%) child questionnaires, and 3393 (88%) FeNO, 3446 (89%) spirometry, and 1795 (46%) DTG-SBW measurements.

LUIS is a rich resource of health-related data, with information on lung function, environmental exposures and respiratory health on Swiss schoolchildren.


  1. Ferrante G, La Grutta S. The Burden of Pediatric Asthma. Front Pediatr. 2018;6:186. doi:.
  2. Lau S, Nickel R, Niggemann B, Grüber C, Sommerfeld C, Illi S, et al.; MAS Group. The development of childhood asthma: lessons from the German Multicentre Allergy Study (MAS). Paediatr Respir Rev. 2002;3(3):265–72. doi:.
  3. Asher MI, Keil U, Anderson HR, Beasley R, Crane J, Martinez F, et al. International Study of Asthma and Allergies in Childhood (ISAAC): rationale and methods. Eur Respir J. 1995;8(3):483–91. doi:.
  4. Pearce N, Aït-Khaled N, Beasley R, Mallol J, Keil U, Mitchell E, et al.; ISAAC Phase Three Study Group. Worldwide trends in the prevalence of asthma symptoms: phase III of the International Study of Asthma and Allergies in Childhood (ISAAC). Thorax. 2007;62(9):758–66. doi:.
  5. Selby A, Munro A, Grimshaw KE, Cornelius V, Keil T, Grabenhenrich L, et al. Prevalence estimates and risk factors for early childhood wheeze across Europe: the EuroPrevall birth cohort. Thorax. 2018;73(11):1049–61. doi:.
  6. Custovic A, Simpson BM, Murray CS, Lowe L, Woodcock A ; NAC Manchester Asthma and Allergy Study Group. The National Asthma Campaign Manchester Asthma and Allergy Study. Pediatr Allergy Immunol. 2002;13(s15):32–7. doi:.
  7. Kuehni CE, Brooke AM, Strippoli MP, Spycher BD, Davis A, Silverman M. Cohort profile: the Leicester respiratory cohorts. Int J Epidemiol. 2007;36(5):977–85. doi:.
  8. Sennhauser FH, Kühni CE. Prevalence of respiratory symptoms in Swiss children: is bronchial asthma really more prevalent in boys? Pediatr Pulmonol. 1995;19(3):161–6. doi:.
  9. Alfvén T, Braun-Fahrländer C, Brunekreef B, von Mutius E, Riedler J, Scheynius A, et al., PARSIFAL study group. Allergic diseases and atopic sensitization in children related to farming and anthroposophic lifestyle--the PARSIFAL study. Allergy. 2006;61(4):414–21. doi:.
  10. Frei R, Roduit C, Bieli C, Loeliger S, Waser M, Scheynius A, et al.; as part of the PARSIFAL study team. Expression of genes related to anti-inflammatory pathways are modified among farmers’ children. PLoS One. 2014;9(3):e91097. doi:.
  11. Riedler J, Braun-Fahrländer C, Eder W, Schreuer M, Waser M, Maisch S, et al.; ALEX Study Team. Exposure to farming in early life and development of asthma and allergy: a cross-sectional survey. Lancet. 2001;358(9288):1129–33. doi:.
  12. Illi S, Depner M, Genuneit J, Horak E, Loss G, Strunz-Lehner C, et al.; GABRIELA Study Group. Protection from childhood asthma and allergy in Alpine farm environments-the GABRIEL Advanced Studies. J Allergy Clin Immunol. 2012;129(6):1470–7.e6. doi:.
  13. Braun-Fahrländer C, Gassner M, Grize L, Takken-Sahli K, Neu U, Stricker T, et al.; Swiss Study on Childhood Allergy and Respiratory symptoms; Air Pollution (SCARPOL) team. No further increase in asthma, hay fever and atopic sensitisation in adolescents living in Switzerland. Eur Respir J. 2004;23(3):407–13. doi:.
  14. Grize L, Gassner M, Wüthrich B, Bringolf-Isler B, Takken-Sahli K, Sennhauser FH, et al.; Swiss Surveillance Programme on Childhood Allergy and Respiratory symptoms with respect to Air Pollution (SCARPOL) team. Trends in prevalence of asthma, allergic rhinitis and atopic dermatitis in 5-7-year old Swiss children from 1992 to 2001. Allergy. 2006;61(5):556–62. doi:.
  15. Stocks J, Sonnappa S, Lum S. Lung function testing in children: importance of race and ethnic-specific reference equations. Expert Rev Respir Med. 2014;8(5):527–31. doi:.
  16. Lunge Zürich. [cited 2020 June 02]; Available from:
  17. Rochat MK, Laubender RP, Kuster D, Braendli O, Moeller A, Mansmann U, et al. Spirometry reference equations for central European populations from school age to old age. PLoS One. 2013;8(1):e52619–52619. doi:.
  18. West EA, Strassmann A, Wang C, Turk A, de Hoogh K, Röösli M, et al. Increase in Airway Obstruction between 1993 and 2012 in Switzerland. An Observational Study. Ann Am Thorac Soc. 2020;17(4):457–65. doi:.
  19. Harris PA, Taylor R, Minor BL, Elliott V, Fernandez M, O’Neal L, et al.; REDCap Consortium. The REDCap consortium: Building an international community of software platform partners. J Biomed Inform. 2019;95:103208. doi:.
  20. Bopp M, Spoerri A, Zwahlen M, Gutzwiller F, Paccaud F, Braun-Fahrländer C, et al. Cohort Profile: the Swiss National Cohort--a longitudinal study of 6.8 million people. Int J Epidemiol. 2009;38(2):379–84. doi:.
  21. Panczak R, Galobardes B, Voorpostel M, Spoerri A, Zwahlen M, Egger M ; Swiss National Cohort and Swiss Household Panel. A Swiss neighbourhood index of socioeconomic position: development and association with mortality. J Epidemiol Community Health. 2012;66(12):1129–36. doi:.
  22. Singer F, Stern G, Thamrin C, Fuchs O, Riedel T, Gustafsson P, et al. Tidal volume single breath washout of two tracer gases--a practical and promising lung function test. PLoS One. 2011;6(3):e17588. doi:.
  23. Robinson PD, Latzin P, Verbanck S, Hall GL, Horsley A, Gappa M, et al. Consensus statement for inert gas washout measurement using multiple- and single- breath tests. Eur Respir J. 2013;41(3):507–22. doi:.
  24. Singer F, Stern G, Thamrin C, Abbas C, Casaulta C, Frey U, et al. A new double-tracer gas single-breath washout to assess early cystic fibrosis lung disease. Eur Respir J. 2013;41(2):339–45. doi:.
  25. Aurora P, Kozlowska W, Stocks J. Gas mixing efficiency from birth to adulthood measured by multiple-breath washout. Respir Physiol Neurobiol. 2005;148(1-2):125–39. doi:.
  26. Van Muylem A, Paiva M, Baran D, Yernault JC. Structural change of the acinus during growth assessed by single-breath tracer gas washouts. Pediatr Pulmonol. 1996;22(4):230–5. doi:.<230::AID-PPUL2>3.0.CO;2-Q
  27. Araya-Cloutier C, Vincken J, Van De Schans M, Hageman J, Schaftenaar G, Den Besten H, et al., European Respiratory Society. ATS/ERS recommendations for standardized procedures for the online and offline measurement of exhaled lower respiratory nitric oxide and nasal nitric oxide, 2005. Am J Respir Crit Care Med. 2005;171(8):912–30. doi:.
  28. Miller MR, Hankinson J, Brusasco V, Burgos F, Casaburi R, Coates A, et al.; ATS/ERS Task Force. Standardisation of spirometry. Eur Respir J. 2005;26(2):319–38. doi:.
  29. Quanjer PH, Stanojevic S, Cole TJ, Baur X, Hall GL, Culver BH, et al.; ERS Global Lung Function Initiative. Multi-ethnic reference values for spirometry for the 3-95-yr age range: the global lung function 2012 equations. Eur Respir J. 2012;40(6):1324–43. doi:.
  30. de Hoogh K, Saucy A, Shtein A, Schwartz J, West EA, Strassmann A, et al. Predicting Fine-Scale Daily NO2 for 2005-2016 Incorporating OMI Satellite Data Across Switzerland. Environ Sci Technol. 2019;53(17):10279–87. doi:.
  31. de Hoogh K, Heritier H, Stafoggia M, Kunzli N, Kloog I. Modelling daily PM2.5 concentrations at high spatio-temporal resolution across Switzerland. Environ Pollut. 2018;233:1147–54. doi:.
  32. Wang X, Ji X. Sample Size Estimation in Clinical Research: From Randomized Controlled Trials to Observational Studies. Chest. 2020;158(1S):S12–20. doi:.
  33. Mallol J, Castro-Rodriguez JA, Cortez E. Effects of active tobacco smoking on the prevalence of asthma-like symptoms in adolescents. Int J Chron Obstruct Pulmon Dis. 2007;2(1):65–9. doi:.
  34. Inchley J, Currie D, Budisavljevic S, Torsheim T, Jåstad A. Cosma Aea. Spotlight on adolescent health and well-being. Findings from the 2017/2018 Health Behaviour in School-aged Children (HBSC) survey in Europe and Canada. Volume 2. Key data. Copenhagen: WHO Regional Office for Europe. 2020.
  35. Gauderman WJ, Avol E, Gilliland F, Vora H, Thomas D, Berhane K, et al. The effect of air pollution on lung development from 10 to 18 years of age. N Engl J Med. 2004;351(11):1057–67. doi:.
  36. Quanjer PH, Stanojevic S. Do the Global Lung Function Initiative 2012 equations fit my population? Eur Respir J. 2016;48(6):1782–5. doi:.
  37. de Onis M, Onyango AW, Borghi E, Siyam A, Nishida C, Siekmann J. Development of a WHO growth reference for school-aged children and adolescents. Bull World Health Organ. 2007;85(9):660–7. doi:.
  38. von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP ; STROBE Initiative. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. J Clin Epidemiol. 2008;61(4):344–9. doi:.
  39. Bundesamt für Statistik. Räumliche Typologien. [cited 2020 May 05]; Available from:
  40. EUROSTAT. Verstädterungsgrad (DEGURBA, Degree of Urbanisation). [cited 2020 May 05]; Available from:
  41. Mozun R, Ardura-Garcia C, de Jong CCM, Goutaki M, Usemann J, Singer F, et al. Cigarette, shisha, and electronic smoking and respiratory symptoms in Swiss children: The LUIS study. Pediatr Pulmonol. 2020;55(10):2806–15. doi:.
  42. Singer F, Abbas C, Yammine S, Casaulta C, Frey U, Latzin P. Abnormal small airways function in children with mild asthma. Chest. 2014;145(3):492–9. doi:.
  43. Singer F, Luchsinger I, Inci D, Knauer N, Latzin P, Wildhaber JH, et al. Exhaled nitric oxide in symptomatic children at preschool age predicts later asthma. Allergy. 2013;68(4):531–8. doi:.