1 Hospital de Dona Estefânia, Immunoallergy, Lisbon, Portugal
2 Faculdade de Ciências Médicas da Universidade Nova de Lisboa, CEDOC, Lisbon, Portugal
3 Faculdade de Ciências Médicas da Universidade Nova de Lisboa, Pathophysiology, Lisbon, Portugal
4 Faculdade de Ciências Médicas da Universidade Nova de Lisboa, Informatics and Biostatistics, Lisbon, Portugal
5 Centro Hospitalar de Lisboa Central, EPE, Gabinete de Apoio Estatístico e Epidemiológico, Lisbon, Portugal
6 Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal
7 Hospital da Luz, Lisbon, Portugal
XXXII Reunião anual da EAACI. Milão, Junho de 2013. (Poster)
Background: Child day care center (DCC) admission is associated with an increased risk of unscheduled medical evaluation due to wheezing. Risk factors for severe episodes of wheezing associated with the air quality of DCC are not yet detailed studied.
Objectives: To explore potential risk factors for episodes of wheezing requiring medical evaluation associated with attendance to DCC.
Methods: Within ENVIRH (Environment and Health in children day care centers - PTDC/SAU-ESA/100275/2008) project, 19 schools in Lisbon and Oporto were selected by stratified sampling followed by cluster analysis. The institutions were assessed for indoor air quality in March 2011. A medical questionnaire evaluating the number and severity of wheezing symptoms was applied to the parents of the participant children, in March and April 2011 (n = 1226). For data analysis, hierarchical regression models were used as children were allocated to a room and each room was allocated to a school. Minimum p-value approach was used to establish a cut-off for cumulative attendance to DCC (in months) associated with a lower risk of wheezing episodes requiring medical evaluation.
Results: Filled in questionnaires from 749 children were obtained (61% return rate), 53.3% from boys. Children's median age was 43 months (P25-P75: 26-58 months) and the median age of admission into the institution was 24 months (P25-P75: 8-40 months). In the assessed months, 68 children (9%) required medical evaluation due to wheezing. Children attending institutions for more than 10 months had less wheezing episodes requiring medical evaluation. In multivariable analysis, only attendance to DCC for less than 10 months remained significant (OR: 2.23, 95% CI: 1.28 to 3.88, p = 0.004), and a marginal effect of total volatile organic compounds (TVOC) was found (OR: 1.07, 95% CI: 0.99 to 1.14, p = 0.085), calculated for each 100 µg/m3 increase in concentration.
Conclusion: Cumulative attendance to DCC was the main factor associated with medical evaluation due to wheezing, in this study. A significant cut-off at 10 months of kindergarten attendance was determined. Of note is also the identified effect of a 7% increase for wheezing occurrence by each 100 µg/m3 increase of TVOC concentration.
Keywords: Total volatile organic compounds, day care centers, wheezing, preschool children