RT Journal Article SR Electronic T1 Latent class identification in wheezing preschool children JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP PA3136 DO 10.1183/13993003.congress-2016.PA3136 VO 48 IS suppl 60 A1 Salvatore Fasola A1 Giovanna Cilluffo A1 Velia Malizia A1 Giuliana Ferrante A1 Laura Montalbano A1 Marco Montalbano A1 Giovanni Viegi A1 Stefania La Grutta YR 2016 UL http://erj.ersjournals.com/content/48/suppl_60/PA3136.abstract AB Background and aim: Since the forced oscillation technique (FOT) has not been used in previous studies on wheezing phenotyping in preschool children, we applied FOT in a large series of outpatients visited at IBIM.Methods: We analyzed 256 consecutively enrolled ≤5 years children with doctor diagnosis of wheezing. Latent Class Analysis (LCA) was performed considering the following personal characteristics: type, cause, recurrence in last 12 months, respiratory resistance (Avr_R(8)), atopy, history of eczema, rhinitis and upper airways infections. High resistance is defined as positive residual of regression on sex, age, height and weight. Risk factors were considered meaningful when they yielded a p-value <0.10 in ANOVA and Chi-square tests. Analyses were performed through R version 3.2.0.Results: Two latent classes were identified. In the first class (71%), children had mainly persistent (59%) and recurrent (50%) wheezing, with high resistance (56%; mean value 9.73±2.75 hPa/(l/s), mean residual 0.35±2.67 hPa/(l/s)) and high prevalence rate of upper airways infections (53%). In the second class (29%), wheezing was mainly late-onset (54%) and episodic (67%), with low resistance (65%; mean value 8.91±2.64 hPa/(l/s), mean residual -0.34±2.48 hPa/(l/s)) and high prevalence rates of rhinitis (76%) and atopy (79%). Membership in the first class was linked to be non-firstborn (p=0.075) and to have history of bronchiolitis (p<0.01). Membership in the second class was associated with older mean age (p<0.01), parental history of allergic diseases (p=0.06) and history of mold exposure (p=0.024).Conclusions: Considering respiratory resistance can improve wheezing phenotype characterization in preschool children.