PLoS One

OBJECTIVE: Different phenotypes of wheezing have been described to date but not in early life. We aim to describe wheezing phenotypes between the ages of two months and one year, and assess risk factors associated with these wheezing phenotypes in a large birth cohort. METHODS: We studied 18,041 infants from the ELFE (French Longitudinal Study of Children) birth cohort. Parents reported wheezing and respiratory symptoms at two and 12 months, and answered a complete questionnaire (exposure during pregnancy, parental allergy). RESULTS: Children with no symptoms (controls) accounted for 77.2%, 2.1% had had wheezing at two months but no wheezing at one year (intermittent), 2.4% had persistent wheezing, while 18.3% had incident wheezing at one year. Comparing persistent wheezing to controls showed that having one sibling (ORa = 2.19) or 2 siblings (ORa = 2.23) compared to none, nocturnal cough (OR = 5.2), respiratory distress (OR = 4.1) and excess bronchial secretions (OR = 3.47) at two months, reflux in the child at 2 months (OR = 1.55), maternal history of asthma (OR = 1.46) and maternal smoking during pregnancy (OR = 1.57) were significantly associated with persistent wheezing. These same factors, along with cutaneous rash in the child at 2 months (OR = 1.13) and paternal history of asthma (OR = 1.32) were significantly associated with increased odds of incident wheezing. Having one sibling (ORa = 1.9) compared to none, nocturnal cough at 2 months (OR = 1.76) and excess bronchial secretions at 2 months (OR = 1.65) were significantly associated with persistent compared to intermittent wheezing. CONCLUSION: Respiratory symptoms (cough, respiratory distress, and excessive bronchial secretion) were significantly associated with a high risk of persistent wheezing at one year. Smoking exposure during pregnancy was also a risk factor for persistent and incident wheezing

Temps d’écran de 2 à 5 ans et demi chez les enfants de la cohorte nationale Elfe

National audienceChildren’s screen time has increased in recent years in France, as shown by repeated cross-sectional surveys. However, no national-scale longitudinal study had been published and data on children aged under 3 years is particularly scarce. We used data from the birth cohort study Elfe to describe total and device-specific screen time of followed children at 2 years, 3-and-a-half years and 5-and-a-half years of age. We also describe differences according to the family’s region of residence, migration history and origin, maternal education level and child sex. After weighting the data, total daily screen time was on average 56 min (95% confidence interval: [55 min-58 min]) at 2 years of age; 1 hr 20 min [1 hr 18 min-1 hr 22 min] at 3-and-a-half years of age; 1 hr 34 min [1 hr 32 min-1 hr 36 min] at 5-and-a-half years of age. Screen time increased substantially between 2 and 3-and-a-half years of age (Spearman’s correlation: 0.50) and between 3-and-a-half and 5-and-a-half years of age (0.67). Overall, screen time was greater in families with a history of migration and a lower level of maternal education. Regional disparities are also noted. Finally, there was no difference by sex at 2 years of age; however, boys spent 10 min longer watching screens than girls did at 5-and-a-half years of age. This is the first study to describe at national level the time children spend watching screens. It will help target families and contexts where screen time exceeds current guidelinesLe temps passé par les enfants devant les écrans a augmenté ces dernières années en France, comme en témoignent diverses enquêtes transversales répétées. Cependant, il n’existe à l’échelle nationale aucune donnée longitudinale, en particulier pour les moins de 3 ans. À partir des données de la cohorte Elfe, nous décrivons le temps d’écran, total et par type d’écran, des enfants suivis à 2 ans, 3 ans et demi et 5 ans et demi. Nous mettons également en avant des disparités selon la région d’habitation de la famille, son histoire et son origine migratoires, le niveau d’études de la mère et le sexe de l’enfant. Après pondération des données, le temps d’écran quotidien était en moyenne de 56 min (intervalle de confiance à 95%: [55-58]) à 2 ans, 1h20 [1h18-1h22] à 3 ans et demi et 1h34 [1h32-1h36] à 5 ans et demi. Ces temps étaient corrélés positivement (0,50 entre 2 et 3 ans et demi ; 0,67 entre 3 ans et demi et 5 ans et demi), démontrant une persistance individuelle de l’utilisation au cours du temps. Dans l’ensemble, les temps d’écran étaient plus élevés chez les familles ayant des origines immigrées, ou un niveau d’études de la mère faible. Des disparités régionales étaient aussi observées. Enfin, si aucune différence entre garçons et filles n’était observée à 2 ans, les garçons utilisaient les écrans 10 minutes de plus que les filles à 5 ans et demi. Cette étude décrit pour la première fois à l’échelle nationale et de façon longitudinale le temps passé par les jeunes enfants devant les écrans. Elle permettra de mieux cibler les familles et les contextes où ce temps excède les recommandations

The external validation of the asthma prediction tool in the French ELFE cohort

BACKGROUND: Existing predictive scores for early identification of children at high risk of developing asthma include invasive procedures, and hence have limited utility in a primary care setting. The Leicestershire respiratory cohort (LRC) has developed a noninvasive asthma prediction tool (APT) for children with promising results. We aimed to perform its external validation in the French general population Etude Longitudinale Francaise depuis l'Enfance (ELFE) cohort. METHODS: Predictive scores were determined at Age 1 and the primary outcome of asthma was defined as parental reporting of "asthma ever or "wheezing in the past 12 months" at Age 5. Logistic regression was used to calculate the odds ratio (OR) and performance measures, and discriminative performance was reported using the receiver operating curve and area under curve (AUC). Calibration was assessed using Hosmer-Lemeshow goodness-of-fit test and visualized with a calibration plot. Overall performance was determined using Brier scores. RESULTS: Of the 10,689 children analyzed: 84.9% were at low, 13.1% medium, and 2% at high risk of developing asthma at Age 5. Children in the medium-risk category were three times more likely to develop asthma (OR = 3.3, 95% confidence interval [CI] = 2.97-3.78) whereas 13 times more likely in the high-risk category (OR = 13.8, 95% CI = 10.2-18.8). The tool's AUC was comparable: LRC 0.74 versus ELFE 0.68; as were the Brier scores LRC 0.16 versus ELFE 0.14. The tool's performance was robust to changes in inclusion criteria and outcome definitions. CONCLUSIONS AND RELEVANCE: Results of the present study and previous validation studies performed in high-risk populations provide a comprehensive measure of the effectiveness of the APT, providing encouragement for its application by general practitioners.Environnement MicroBiologique et Risque Allergique, Suivi des Enfants à 5 an

Cohort Profile: The French National cohort of children ELFE: birth to 5 years

International audienceELFE is the first French national birth cohort. Its objective is to study determinants of the development, health and socialization of children from birth to adulthood through a multidisciplinary approach. A total of 18 329 children were recruited at birth in a random sample of maternity units in metropolitan France during 25 selected days of 2011 spread over the year. Follow-up in the first 5 years consisted of telephone interviews of both parents of the child at age 2 months and 1 year and 2 years, and of one parent at age 3.5 years; a home visit at age 3.5 years; questionnaires to the child’s physician at age 2 years, the child’s nursery school doctor at age 3 to 4 years, and the child’s nursery schoolteacher at age 4 years. Participation rates at the age 2-month, 1- and 2-year and 3.5-year parental interviews were 92%, 86%, 82% and 80%, espectively, of contacted participants. The main categories of data collected concern: sociodemographic characteristics; family life; parental health, behaviour and life values; child development and health; child school performance, behaviour, and socialization; day care and school; and childhood environmental exposures. The ELFE has an open-data policy after an 18-month exclusivity period following each release of new data. The data-access policy, study protocols, questionnaires and data catalogue can be found online: [https://www.ELFE-france.fr/en/

Flow chart.

<p>Flow chart.</p

Prevalence of wheezing and other respiratory symptoms at two months and one year in ELFE cohort.

<p>Prevalence of wheezing and other respiratory symptoms at two months and one year in ELFE cohort.</p

Factors associated with persistent and incident wheezing at one year compared to non-wheezers (odds-ratios from backward logistic regressions).

<p>Factors associated with persistent and incident wheezing at one year compared to non-wheezers (odds-ratios from backward logistic regressions).</p

Parental risk factors associated with wheezing phenotypes in ELFE cohort.

<p>Parental risk factors associated with wheezing phenotypes in ELFE cohort.</p

Multivariable analysis.

<p>Multivariable analysis.</p

Multivariable analysis.

<p>Multivariable analysis.</p