Constructed variables

	Topic			Documentation
EQR1	Diet during the pregnancy	B de Lauzon-Guillain, INSERM CRESS équipe ORCHAD	Identifying mothers whose food consumption data we have, and for whom we can construct daily intakes in grams/mL for each item in the questionnaire, as well as nutritional daily intakes (energy and nutrients).	Yes
EQR2	Mothers’ employment	Equipe Santé Travail Environnement, ISPED Centre Inserm U897, Université de Bordeaux	Coding for mothers’ job and sector of the economy during the pregnancy.	Yes
EQR3	Milk diet during the 1st year	B de Lauzon-Guillain, INSERM CRESS équipe ORCHAD	Age at which infant milk and other types of milk were introduced in the child’s diet, and when breastfeeding stopped, distinguishing between exclusive breastfeeding and mixed milk diets.	Yes
EQR5	Fathers’ employment	projet COSRED	Coding for fathers’ job and sector of the economy during the pregnancy.	Yes
EQR8	Visual impairment
EQR9	Physical activity during the pregnancy	Patricia Dargent-Molina (groupe Activité physique Elfe	Identifying physical activities practiced during the pregnancy. Using the self-administered questionnaire on lifestyle that mothers completed at the maternity ward, after the child’s birth. Information about the 3 last months of pregnancy, includes activity intensity scores.	Yes
EQR11	Congenital malformation	Nathalie Lelong du registre des malformations congénitales de PARIS en lien avec l’équipe 9 de l’UMR 1085 impliquée dans le projet COSRED (R.Garlantézec et C.Warembourg	Congenital malformation variables coded, using medical records and relevant variables from questionnaires at 2 months, ages 1 and 2: health problems, medical consultations, hospitalisations. Coding follows the recommendations of the European Surveillance of congénital anomalies network.	Yes
EQR12	Socio-demographic data	Barbara Castillo, Marieke Heers, Lidia Panico, Laurent Toulemon, Khaled Ben Jemaa, Malamine Gassama, Jean LYess Lanoé	Sociodemographic characteristics: cohabiting parents, family structure, housing characteristics, migration background, parents’ age, education, work situation, income.	Ages 0-2 Age 3.5 Age 5.5
EQR13	Ultrasound, fetal growth	Anne Forhan, Morgane Le Guern, Farid Er-razzouk	Measurements of gestational age, craniocaudal length, femoral length, transverse abdominal muscle diametre, abdominal circumference, biparietal diameter: internal Z-scores, Intergrowth-21st (IG) Z-scores, 2006 French Z-scores (CFEF). Estimated fetal weight using Hadlock and Bouton equations.	Yes
EQR14	Dietary exposures	Cécile Chevrier	Evaluating exposures to pesticides during the pregnancy.
EQR15	Mothers’ pathological history	MA Charles, M Lecorguillé	Mothers’ pathology history found in medical records, with enough observations to run specific analyses. Pathologies organised by organ and systems involved. Variable identifying pathologies that might affect the pregnancy and fetal growth: can be used to exclude observations in analyses on the relationship between other factors and pathologies during the pregnancy or fetal growth.	Yes
EQR16	Dietary diversification	Sophie Nicklaus, INRA CSGA	Dietary diversification variables. Diversification stages at each follow-up, age at introduction. We use two definitions: the OMS definition--introducing a type of food means tasting it once, and the regular definition--introducing a type of food means having it multiple times.	Yes
EQR17	Pesticides use at home
EQR18	Indicator for the proximity of agricultural areas
EQR20	Child growth, anthropometric measurements	Anne Forhan, Jérémie Botton, Malamine Gassama, sous la direction de Barbara Heude	Corrected anthropometric measurements for weight, height, and head circumference, from birth to age 3.5. Errors that were present in the initial data for different reasons were corrected, using the same method across the three types of measurements, independently.	Yes
EQR21	Quality of mothers’ diet during the pregnancy	B de Lauzon-Guillain, INSERM CRESS équipe ORCHAD	Two composite indices on the quality of mothers’ diet during the last three months of pregnancy.	Yes Annx1 Annx2
EQR23	Native region (World Bank classification)
EQR25	Maternal exposures to agricultural pesticides
EQR27	Exposure to food contaminants during the pregnancy	Blandine de Lauzon-Guillain CRESS – Equipe EAROH	Depuis les données calculées pour l’EQR1, mise à disposition pour chaque contaminant alimentaire de 3 valeurs (Hypothèse haute : valeurX	Yes
EQR28	MacArthur grammar scores at age 2	Frédérique Gayraud	At the end of the MacArthur parent questionnaire, parents are asked about Elfe’s three longest sentences yet. Here are resulting scores: mean length of sentences, by word count.	Yes
EQR29	Languages	Jean-LYess Lanoë	Languages spoken to the child by parents and grandparents, combining information from different sweeps and from both parents’ questionnaires. Some responses were plain text and needed coded. To limit secondary identification, rare languages were grouped into larger categories.	2 months-5.5 years old Age 10.5
EQR30	Indicators for neurodevelopment disorders	Laurence Germany	Identifies children who have a neurodevelopmental disorder according to parents. From ages 2 to 10.5, indicator variables flag the following: autism spectrum disorders, delay and disorders in language acquisition, motor delay and disorders, other neurodevelopmental disorders, attention-deficit hyperactivity disorder-behavioural disorders.	Yes
EQR33	Allergies and respiratory health	Blandine de Lauzon-Guillain, Rosalie Delvert	Variables on allergies and respiratory health, created as a part of the LifeCycle project.	Yes
EQR37	Screen use	Mélèa Saïd et Jonathan Bernard	The different sweeps of Elfe contain information linked to screens (TV, computer, etc.) at to digital technologies. We know about what electronic devices are in the home, how much children and parents use them--how long and how often for different types of screens. We also have more qualitative information about how parents deal with them and regulate their use. For each sweep, and for each type of screen, we’ve constructed three quantitative variables that average screentime in hours per day: one variable averages screentime on weekdays Monday to Friday, a second on weekend days Saturday and Sunday, and a third over the whole week Monday to Sunday.	Yes
EQR38	Sleep	Mélèa Saïd, Sabine Messayke et Sabine Plancoulaine	Variables on sleep duration, quality, patterns and disorders, from ages 1 to 10.5.	Yes
EQR39	Child psychomotor development	Muriel Tafflet, Mélèa Saïd, Jonathan Bernard, Marie Aline Charles	The Child Development Inventory (CDI) is a quick and easy tool used by health professionals to detect development issues and learning difficulties among children aged 15 to 72 months. Items were translated into French and adapted by the neuropsychologist Michel Duyme.	Yes
EQR40	M-CHAT (Modified Checklist for Autism in Toddlers) score at age 2	M Tafflet, MA Charles	Recommendations on how to use the M-Chat questionnaire distributed at age 2.	Yes

Constructed variables: why do they exist?

The Elfe data collected from families contains a lot of information, and can make analyses quite complicated. It requires in-depth knowledge about how it was collected, and scientific skills to be analysed to their full potential. It may also turn out that some variables reveal participants’ identity, sometimes indirectly. Consequently, researchers can’t use them, even if it means missing out on a wealth of information. More information on constructed variables here.

Information

Users who’d like to use these variables must specify which EQR(s) they want in the ’Comments’ part of the CADE form.

Note

Contrary to variables from the survey, users don’t need to specify which exact variables they need. You’ll access all of the variables from the EQR your variable is included in.