Maelstrom Research

Québec Longitudinal Study of Child Development

The Quebec Longitudinal Study of Child Development (QLSCD) was set up in the end of the 1990s. About 20 years later, a second study was set up. The general objective of the QLSCD 1st edition - Cohort 1996 (*In 2001, I was 5 years old*) is to better understand the link between the development of the child and their adaptation upon entering school. The initial main objective of the QLSCD 1st edition - Cohort 1998 (1998-2015, *I am, I'll be*) was to identify factors that, coming into play during early childhood, affect the social adjustment and academic performance of young Quebecers. The revised main objective (2017-2023) is to gain a better understanding of the factors that, when implemented at different stages in life, are linked to the overall well-being of young adults in Québec. The main objective of QLSCD 2nd edition - Cohort 2018 and Cohort 2020-2021 (*Growing Up in Québec*) is to identify the developmental trajectories and factors that contribute to the well-being of young people born in Quebec. Some of its sub-objectives are: * To study the factors that predict the adoption of healthy lifestyles and optimal health; * To identify the predictors of school perseverance and success; * To identify the process that promote social adaptation; * To identify factors associated with social mobility; and * To study the process that leads to successful socio-professional integration.

Overview

Acronym

QLSCD

Website

QLSCD

Investigators

Dr. Isabelle Archambault

Université de Montréal

Dr. Caroline Fitzpatrick

Université de Sherbrooke

Dr. Xavier Saint-Denis

Institut national de la recherche scientifique

Dr. Frank Vitaro

Université de Montréal

Dr. Véronique Dupéré

Université de Montréal

Dr. Richard E. Tremblay

Université de Montréal

Dr. Lise Dubois

University of Ottawa

Dr. Tamarha Pierce

Université Laval

Contacts

Nancy Illick

Institut de la statistique du Québec

General Design

Study design

Cohort

Start - End Year

1996 -

General Information on Follow Up (profile, frequency)

QLSCD 1 - Cohort 1996 was followed-up yearly from 5 months to 18 years old.

QLSCD 1 - Cohort 1998 was followed-up yearly from 5 months to about 25 years of age (in 2023), with breaks at ages 9, 11, 14, 16, 18, 20, 22, and 24.

QLSCD 2 - Cohort 2018 was followed-up every year since 2018.

QLSCD 2 - Cohort 2020-2021 was first contacted in March 2021 and is meant to be followed up to adulthood, every year or every two years.

Recruitment Target

Individuals

Number of Participants

7,641

Number of Participants with Biological Samples

1,572

Supplementary information about number of participants

QLSCD 1 - Cohort 1996: 572 participants
QLSCD 1 - Cohort 1998: 2,120 participants
QLSCD 2 - Cohort 2018: 449 participants
QLSCD 2 - Cohort 2020-2021: 4,500 participants

Supplementary Information

QLSCD 1 - Cohort 1998: Other biological samples were collected when the participants were 17 years old.
QLSCD 2 - Cohort 2020-2021 did not collect biological samples.

Access

Availability of data and biosamples

Possible Access to Data
Possible Access to Biosamples
Other

Availability of access information

By contacting the study representative: Nancy Illick (Institut de la statistiques du Québec)

Sector of research

	Possible Access to Data	Possible Access to Biosamples
Investigators from the public sector
Investigators from the private sector
Investigators from not-for-profit organization

Transfer

	Possible Access to Data	Possible Access to Biosamples
Can leave the study facility
Can leave the country

Cost

Possible Access to Data	No Cost
Possible Access to Biosamples	Variable Cost

Cost reduction for co-analyses

Possible Access to Data
Possible Access to Biosamples

Yes

Not applicable

Don't know

Marker Papers

Orri M, Boivin M, Chen C et al. Cohort Profile: Quebec Longitudinal Study of Child Development (QLSCD). Social Psychiatry and Psychiatric Epidemiology, 2021;56: 883–894.

PUBMED 33185737

Supplementary Information

QLSCD 1 - Cohort 1998: Questionnaires available here
QLSCD 2 - Cohort 2020-2021: Questionnaires soon to be available (in 2022) QLSCD 2 website

Timeline

Populations

An interview was conducted at the participant's home with the person who best knows the child. The Interviewer Completed Computerized Questionnaire (ICCQ) and Paper Questionnaire Completed by the Interviewer (PQCI) were used. The Self-Administered Questionnaire for Mother (SAQM) and Self-Administered Questionnaire for Father (SAQF) were to be completed by each biological parent (whether resident or non-resident) and sent back by postal service.

A cognitive task was administered for the child.

The Observations of Family Life (OLF) was used to describe the home environment.

A check of obstetric medical records was performed to obtain information regarding the pregnancy and birth.

Start Date

1998 (March)

End Date

1998 (December)

Data sources

Questionnaires
Cognitive measures
Other : Home observation, medical record of the mother (obstetric)

A cognitive task was administered for the child.

The Observations of Family Life (OLF) was used to describe the home environment.

If not already obtained in 1998, a check of obstetric medical records was performed to obtain information regarding the pregnancy and birth.

Start Date

1999 (March)

End Date

1999 (December)

Data sources

Questionnaires
Cognitive measures
Other : Home observation, mother's medical record (obstetric)

The Observations of Family Life (OLF) was used to describe the home environment.

A cognitive task was administered for the child.

Anthropometric measures of the child were taken.

If not already obtained, a check of obstetric medical records was performed to obtain information regarding the pregnancy and birth.

Start Date

2000 (March)

End Date

2000 (November)

Data sources

Questionnaires
Cognitive measures
Physical measures
Other : Mother's medical record (obstetric)

An interview was conducted at the participant's home with the person who best knows the child. The Interviewer Completed Computerized Questionnaire (ICCQ), Self-Assessment Questionnaires (SAQS) and Paper Questionnaire Completed by the Interviewer (PQCI) were used. The Self-Administered Questionnaire for Mother (SAQM) and Self-Administered Questionnaire for Father (SAQF) were to be completed by each biological parent (whether resident or non-resident) and sent back by postal service. An observational questionnaire was completed by the interviewer.

A cognitive task was completed by the child.

Anthropometric measures of the child were taken.

If not already obtained, a check of obstetric medical records was performed to obtain information regarding the pregnancy and birth.

Start Date

2001 (March)

End Date

2001 (November)

Data sources

Questionnaires
Cognitive measures
Physical measures
Other : Mother's medical record (obstetric)

Cognitive tasks and a questionnaire were completed by the child.

Anthropometric measures of the child were taken.

If not already obtained, a check of obstetric medical records was performed to obtain information regarding the pregnancy and birth.

Start Date

2002 (March)

End Date

2002 (June)

Data sources

Questionnaires
Cognitive measures
Physical measures
Other : Mother's medical record (obstetric)

A 24-hour recall interview was conducted at the participant's home with the person who best knows the child regarding different aspects of the child's nutrition. A second 24-hour recall interview regarding the child's nutrition was conducted with approximately 50% of the participants.

A self-administered questionnaire was completed by the parents.

If the child attended daycare, a checklist was completed by the person in charge of the meals at the daycare. The nutritionist also visited the daycare to complete missing information on the checklist.

Anthropometric measures of the child were taken.

Start Date

2002 (March)

End Date

2002 (July)

Data sources

Questionnaires
Physical measures

A phone interview was conducted with the person who best knows the child. The Interviewer Completed Computerized Questionnaire (ICCQ), Self-Assessment Questionnaires (SAQS) and Paper Questionnaire Completed by the Interviewer (PQCI) were used. The Self-Administered Questionnaire for Mother (SAQM) and Self-Administered Questionnaire for Father (SAQF) were to be completed by each biological parent (whether resident or non-resident) and sent back by postal service.

Cognitive tasks were completed by the child either at home, daycare or preschool.

If not already obtained, a check of obstetric medical records was performed to obtain information regarding the pregnancy and birth.

Start Date

2003 (March)

End Date

2003 (June)

Data sources

Questionnaires
Cognitive measures
Other : Mother's medical record (obstetric)

An interview was conducted by phone or at the participant's home with the person who best knows the child. The Interviewer Completed Computerized Questionnaire (ICCQ) was used.

Self-administered questionnaires were to be completed by each biological parent (whether resident or non-resident) and sent back by postal service or handed to the interviewer during the home visit. The Self-Administered Questionnaire for Teacher (SAQT) was completed by the child's teacher regarding the child's development at school and on friendships (best friend) in class.

Cognitive tasks were completed by the child either at home or at school.

Education information was taken from database.

Start Date

2004 (March)

End Date

2004 (June)

Data sources

Questionnaires
Cognitive measures
Administrative databases

Data sources - Administrative databases

Socioeconomic databases

The child completed an evaluation of his physical condition and other psychomotor activities. This evaluation took place at school or at home depending on the parent's choice.

Start Date

2004 (March)

End Date

2004 (August)

Data sources

Physical measures

An interview was conducted at the participant's home with the person who best knows the child. The Interviewer Completed Computerized Questionnaire (ICCQ) was used. The Self-Administered Questionnaire for Mother (SAQM) was to be completed by the mother (whether resident or non-resident) and handed to the interviewer during the home visit.

The Self-Administered Questionnaire for Teacher (SAQT) was completed by the child's teacher regarding the child's development at school. An observational questionnaire was completed by the interviewer.

Cognitive tasks were completed by the child either at home, or at school.

Anthropometric measures of the child were taken.

Education information was taken from database.

Start Date

2005 (March)

End Date

2005 (June)

Data sources

Questionnaires
Cognitive measures
Physical measures
Administrative databases

Data sources - Administrative databases

Socioeconomic databases

The child completed an evaluation of his physical condition and other psychomotor activities. This evaluation took place at school or at home depending on the parent's choice.

Start Date

2006 (March)

End Date

2006 (June)

Data sources

Physical measures

Cognitive tasks were completed by the child either at home, or at school.

Anthropometric measures of the child were taken.

Education information was taken from database.

Start Date

2006 (March)

End Date

2006 (June)

Data sources

Questionnaires
Cognitive measures
Physical measures
Administrative databases

Data sources - Administrative databases

Socioeconomic databases

A home or phone interview was conducted with the person who best knows the child. The Interviewer Completed Computerized Questionnaire (ICCQ) was used. Self-administered questionnaires were to be completed by biological parents (whether residents or non-residents) and sent back by postal service or handed to the interviewer during the home visit.

An observational questionnaire was completed by the interviewer.

Cognitive tasks were completed by the child either at home, or at school.

Anthropometric measures of the child were taken.

Education information was taken from database.

Start Date

2008 (February)

End Date

2008 (June)

Data sources

Questionnaires
Cognitive measures
Physical measures
Administrative databases

Data sources - Administrative databases

Socioeconomic databases

Parents completed a self-administered questionnaire.

A home visit by a nurse was scheduled for sample collection, child measurements and completion of a questionnaire with the child.

A saliva sampling toolkit with instructions for parent and child was given to the parent.

Start Date

2008 (March)

End Date

2009 (March)

Data sources

Questionnaires
Physical measures
Biosamples

Data sources - Biosamples

Blood
Saliva

A home or phone interview was conducted with the person who best knows the child. The Interviewer Completed Computerized Questionnaire (ICCQ) was used. The Self-Administered Questionnaire for Mother (SAQM) was to be completed by the mother (whether resident or non-resident) and sent back by postal service or handed to the interviewer during the home visit.

The Computerized Questionnaire for Child (CQC) was completed either at home or at school.

The Self-Administered Questionnaire for Teacher (SAQT) was completed by the child's teacher regarding the child's development at school and an observational questionnaire was completed by the interviewer.

Anthropometric measures of the child were taken.

Education information was taken from database.

Start Date

2010 (February)

End Date

2010 (June)

Data sources

Questionnaires
Physical measures
Administrative databases

Data sources - Administrative databases

Socioeconomic databases

A home or phone interview was conducted with the person who best knows the child. The Interviewer Completed Computerized Questionnaire (ICCQ) was used. Self-administered paper questionnaires were to be completed by biological parents (whether residents or non-residents) and sent back by postal service or handed to the interviewer during the home visit.

The Self-Administered Questionnaire for Teacher (SAQT) was completed by the child's French/English and Math teacher regarding the child's development at school and an observational questionnaire was completed by the interviewer.

The Computerized Questionnaire for Child (CQC) was completed either at home or at school.

Anthropometric measures of the child were taken.

Education information was taken from database.

Start Date

2011 (February)

End Date

2011 (June)

Data sources

Questionnaires
Physical measures
Administrative databases

Data sources - Administrative databases

Socioeconomic databases

A home or phone interview was conducted with the person who best knows the child.The Interviewer Completed Computerized Questionnaire (ICCQ) was used. The Self-Administered Questionnaire for Mother (SAQM) was to be completed by the mother (whether resident or non-resident) and sent back by postal service or handed to the interviewer during the home visit.

The Teenager's Online Questionnaire (TOQ) was completed by the teen.

Education information was taken from database.

Start Date

2013 (February)

End Date

2013 (June)

Data sources

Questionnaires
Administrative databases

Data sources - Administrative databases

Socioeconomic databases

A home or phone interview was conducted with the person who best knows the child.The Interviewer Completed Computerized Questionnaire (ICCQ) was used. The Self-Administered Questionnaire for Mother (SAQM) was to be completed by the mother (whether resident or non-resident) and sent back by postal service or handed to the interviewer during the home visit.

The Teenager's Online Questionnaire (TOQ) was completed by the teen.

Education information was taken from database.

Blood samples were collected.

Start Date

2015 (February)

End Date

2015 (June)

Data sources

Questionnaires
Biosamples
Administrative databases

Data sources - Biosamples

Blood

Data sources - Administrative databases

Socioeconomic databases

A questionnaire or phone interview for the child was completed. Information was collected about the hair sample, lifestyle habits, and health.

A saliva sample was collected and a lock of hair was provided by the young respondent himself and returned to the Institut de la statistique du Québec (ISQ).

Start Date

2015 (February)

End Date

2015 (May)

Data sources

Questionnaires
Biosamples

Data sources - Biosamples

Saliva
Hair

The Teenager's Online Questionnaire (TOQ) was administered or a phone interview was completed with the child.

Education information was taken from database.

Start Date

2017 (February)

End Date

2017 (May)

Data sources

Questionnaires
Administrative databases

Data sources - Administrative databases

Socioeconomic databases

Information was collected about values and confidence, prosocial behaviour, romantic relationships, Attention deficit without hyperactivity, eating disorders, use of psychotropic substances, depression, generalized anxiety disorders, antisocial behaviours, victimization, mood disorders, psychopathy, suicide self-mutilation and involvement.

Start Date

2018 (March)

End Date

2018 (June)

Data sources

Questionnaires

Information was collected about family, interpersonal relations, career choices, educational background and school engagement, stress, health and well-being, political interest, work experiences, financial situation, lifestyle habits, and sleeping habits. Education information was taken from database.

Start Date

2019 (February)

End Date

2019 (June)

Data sources

Questionnaires
Administrative databases

Data sources - Administrative databases

Socioeconomic databases

Information was collected about socioeconomic environment, physical environment, development, nutrition and breastfeeding, diet, sleep, temperament and behavior. Neighborhood observation and home environment inventory information was also collected. Cognitive measures were performed. Information was documented about health problems and the care received, from medical files from pregnancy to the birth of the child. The vaccination record was also accessed for data. Different facets of mother and child interaction as well as assessment of the mental-attentional capacity were measured through video recordings.

Start Date

1996 (October)

End Date

1997 (September)

Data sources

Questionnaires
Cognitive measures
Other : Medical files, vaccination record, observation videos

Start Date

1997 (October)

End Date

1998 (September)

Data sources

Questionnaires
Cognitive measures
Other : Medical files, vaccination record, observation videos

Start Date

1998 (November)

End Date

1999 (October)

Data sources

Questionnaires
Cognitive measures
Other : Medical files, vaccination record, observation videos

Start Date

1999 (November)

End Date

2000 (October)

Data sources

Questionnaires
Cognitive measures
Other : Medical files, vaccination record, observation videos

Information was collected about socioeconomic environment, physical environment, development, health problems, care received, lifestyle behaviours (sleep, nutrition, diet), temperament and behavior. Cognitive measures were perfomed.

Start Date

2001 (May)

End Date

2002 (April)

Data sources

Questionnaires
Cognitive measures

Start Date

2002 (May)

End Date

2003 (April)

Data sources

Questionnaires
Cognitive measures

Start Date

2003 (May)

End Date

2004 (April)

Data sources

Questionnaires
Cognitive measures

Start Date

2004 (May)

End Date

2005 (April)

Data sources

Questionnaires
Cognitive measures

Start Date

2005 (May)

End Date

2006 (April)

Data sources

Questionnaires
Cognitive measures

Start Date

2006 (May)

End Date

2007 (April)

Data sources

Questionnaires
Cognitive measures

Start Date

2007 (May)

End Date

2008 (April)

Data sources

Questionnaires
Cognitive measures

Start Date

2008 (May)

End Date

2009 (April)

Data sources

Questionnaires
Cognitive measures

Start Date

2009 (May)

End Date

2010 (April)

Data sources

Questionnaires
Cognitive measures

Start Date

2010 (May)

End Date

2011 (April)

Data sources

Questionnaires
Cognitive measures

Start Date

2011 (May)

End Date

2012 (April)

Data sources

Questionnaires
Cognitive measures

Start Date

2012 (May)

End Date

2013 (April)

Data sources

Questionnaires
Cognitive measures

Start Date

2013 (May)

End Date

2014 (April)

Data sources

Questionnaires
Cognitive measures

Start Date

2014 (May)

End Date

2015 (April)

Data sources

Questionnaires
Cognitive measures

Information about family structure, physical and social environment during pregnancy was collected.

Start Date

2018 (October)

End Date

2019 (March)

Data sources

Questionnaires

Information about family structure, physical and social environment during pregnancy was collected.

Start Date

2019 (October)

End Date

2020 (March)

Data sources

Questionnaires

Information about family structure, physical and social environment during pregnancy was collected.

Start Date

2020 (October)

End Date

2020 (December)

Data sources

Questionnaires

Information about family structure, physical and social environment during pregnancy was collected.

Start Date

2021 (October)

End Date

2022 (March)

Data sources

Questionnaires

Information about family structure, physical and social environment during pregnancy was collected.

Start Date

2021 (May)

End Date

2022 (March)

Data sources

Questionnaires

Information about family structure, physical and social environment during pregnancy was collected.

Start Date

2022 (May)

End Date

2023 (March)

Data sources

Questionnaires

QLSCD 1 - Cohort 1998

The population was composed of babies (single births only) aged 59 or 60 gestational weeks at the beginning of each data collection period, born to mothers living in Quebec.

Selection Criteria

Newborns

Countries

Canada

Canadian Provinces

Quebec

Territory

Quebec

Health Status

Some children were excluded because of constraints linked to the sample frame or major health problems, such as premature babies whose gestation lasted less than 24 weeks or more than 42 weeks and babies whose sex was unknown at participant selection.

Other Criteria

Mothers living in the sociosanitary areas 10 (North-of-Quebec), 17 (Cree territory) and 18 (Inuit territory) and mothers living on Indian reserves were excluded.

Minimum age: 59 gestational weeks at the beginning of each collection period at time 1

Maximum age: 60 gestational weeks at the beginning of each collection period at time 1

Sources of Recruitment

General Population

Selected sample

Sample Size

Number of Participants: 2,120
Number of Participants with Biological Samples: 1,000
Supplementary information about number of participants: Data collection 1998: 2,120 participants
Data collection 1999: 2,045 participants
Data collection 2000: 1,997 participants
Data collection 2001: 1,950 participants
Data collection 2002: 1,944 participants
Nutrition Data collection 2002: 1,550 participants
Data collection 2003: 1,776 participants
Data collection 2004: 1,529 participants
Psychomotricity Data collection 2004: 1,529 participants
Data collection 2005: 1,537 participants
Data collection 2006: 1,526 participants
Psychomotricity Data collection 2006: 1,526 participants
Data collection 2008: 1,402 participants
Health Data collection 2008-2009: 1,000 participants
Data collection 2010: 1,415 participants
Data collection 2011: 1,312 participants
Data collection 2013: 1,466 participants
Data collection 2015: 1,348 participants
Data collection 2017: 1,401 participants
Mental Health Data collection 2018: 1,245 participants
Data collection 2019: 1,323 participants
Nutrition data collection 2020: 908 participants
COVID-19 data collection 2020: 1,182 participants
Data collection 2021: 1,337 participants
Resilience data collection 2021: 1,327 participants

Data Collection Events

#	Name	Data sources	Data sources - Biosamples	Start	End
1	QLSCD 1 - Cohort 1998 - Data collection 1998	Questionnaires Cognitive measures Other : Home observation, medical record of the mother (obstetric)		1998 (March)	1998 (December)
2	QLSCD 1 - Cohort 1998 - Data collection 1999	Questionnaires Cognitive measures Other : Home observation, mother's medical record (obstetric)		1999 (March)	1999 (December)
3	QLSCD 1 - Cohort 1998 - Data collection 2000	Questionnaires Cognitive measures Physical measures Other : Mother's medical record (obstetric)		2000 (March)	2000 (November)
4	QLSCD 1 - Cohort 1998 - Data collection 2001	Questionnaires Cognitive measures Physical measures Other : Mother's medical record (obstetric)		2001 (March)	2001 (November)
5	QLSCD 1 - Cohort 1998 - Data collection 2002	Questionnaires Cognitive measures Physical measures Other : Mother's medical record (obstetric)		2002 (March)	2002 (June)
6	QLSCD 1 - Cohort 1998 - Nutrition Data collection 2002	Questionnaires Physical measures		2002 (March)	2002 (July)
7	QLSCD 1 - Cohort 1998 - Data collection 2003	Questionnaires Cognitive measures Other : Mother's medical record (obstetric)		2003 (March)	2003 (June)
8	QLSCD 1 - Cohort 1998 - Data collection 2004	Questionnaires Cognitive measures Administrative databases		2004 (March)	2004 (June)
9	QLSCD 1 - Cohort 1998 - Psychomotricity Data collection 2004	Physical measures		2004 (March)	2004 (August)
10	QLSCD 1 - Cohort 1998 - Data collection 2005	Questionnaires Cognitive measures Physical measures Administrative databases		2005 (March)	2005 (June)
11	QLSCD 1 - Cohort 1998 - Psychomotricity Data collection 2006	Physical measures		2006 (March)	2006 (June)
12	QLSCD 1 - Cohort 1998 - Data collection 2006	Questionnaires Cognitive measures Physical measures Administrative databases		2006 (March)	2006 (June)
13	QLSCD 1 - Cohort 1998 - Data collection 2008	Questionnaires Cognitive measures Physical measures Administrative databases		2008 (February)	2008 (June)
14	QLSCD 1 - Cohort 1998 - Health Data collection 2008-2009	Questionnaires Physical measures Biosamples	Blood Saliva	2008 (March)	2009 (March)
15	QLSCD 1 - Cohort 1998 - Data collection 2010	Questionnaires Physical measures Administrative databases		2010 (February)	2010 (June)
16	QLSCD 1 - Cohort 1998 - Data collection 2011	Questionnaires Physical measures Administrative databases		2011 (February)	2011 (June)
17	QLSCD 1 - Cohort 1998 - Data collection 2013	Questionnaires Administrative databases		2013 (February)	2013 (June)
18	QLSCD 1 - Cohort 1998 - Data collection 2015	Questionnaires Biosamples Administrative databases	Blood	2015 (February)	2015 (June)
19	QLSCD 1 - Cohort 1998 - Biological Embedding of Childhood Adversity Data collection 2015	Questionnaires Biosamples	Saliva Hair	2015 (February)	2015 (May)
20	QLSCD 1 - Cohort 1998 - Data collection 2017	Questionnaires Administrative databases		2017 (February)	2017 (May)
21	QLSCD 1 - Cohort 1998 - Mental health Data collection 2018	Questionnaires		2018 (March)	2018 (June)
22	QLSCD 1 - Cohort 1998 - Data collection 2019	Questionnaires Administrative databases		2019 (February)	2019 (June)

QLSCD 1 - Cohort 1996

The population was composed of babies aged between 60 and 61 weeks of gestation at the beginning of the data collection who were born to mothers living in Quebec.

Selection Criteria

Newborns

Countries

Canada

Canadian Provinces

Quebec

Territory

Quebec, Montreal, Chaudière-Appalaches, Laval, Lanaudière, Laurentides and Montérégie

Other Criteria

English or French-speaking

Sources of Recruitment

General Population

Selected sample

Supplementary Information

Participants were selected from specific health regions; the towns located about less than an hour drive from Montreal. Health regions located approximately less than an hour drive from Quebec City were also selected. The cities were chosen based on two criteria: the population of the city and the available traffic routes. After the sample was drawn by the Bureau de la statistique du Québec, Santé Québec received the list of names, addresses and telephone numbers of households to be interviewed. Recruitment was done through telephone calls.

Sample Size

Number of Participants: 572
Number of Participants with Biological Samples: 572

Data Collection Events

#	Name	Data sources	Start	End
0	QLSCD 1 - Cohort 1996 - Data collection 1996	Questionnaires Cognitive measures Other : Medical files, vaccination record, observation videos	1996 (October)	1997 (September)
1	QLSCD 1 - Cohort 1996 - Data collection 1997	Questionnaires Cognitive measures Other : Medical files, vaccination record, observation videos	1997 (October)	1998 (September)
2	QLSCD 1 - Cohort 1996 - Data collection 1998	Questionnaires Cognitive measures Other : Medical files, vaccination record, observation videos	1998 (November)	1999 (October)
3	QLSCD 1 - Cohort 1996 - Data collection 1999	Questionnaires Cognitive measures Other : Medical files, vaccination record, observation videos	1999 (November)	2000 (October)
4	QLSCD 1 - Cohort 1996 - Data collection 2001	Questionnaires Cognitive measures	2001 (May)	2002 (April)
5	QLSCD 1 - Cohort 1996 - Data collection 2002	Questionnaires Cognitive measures	2002 (May)	2003 (April)
6	QLSCD 1 - Cohort 1996 - Data collection 2003	Questionnaires Cognitive measures	2003 (May)	2004 (April)
7	QLSCD 1 - Cohort 1996 - Data collection 2004	Questionnaires Cognitive measures	2004 (May)	2005 (April)
8	QLSCD 1 - Cohort 1996 - Data collection 2005	Questionnaires Cognitive measures	2005 (May)	2006 (April)
9	QLSCD 1 - Cohort 1996 - Data collection 2006	Questionnaires Cognitive measures	2006 (May)	2007 (April)
10	QLSCD 1 - Cohort 1996 - Data collection 2007	Questionnaires Cognitive measures	2007 (May)	2008 (April)
11	QLSCD 1 - Cohort 1996 - Data collection 2008	Questionnaires Cognitive measures	2008 (May)	2009 (April)
12	QLSCD 1 - Cohort 1996 - Data collection 2009	Questionnaires Cognitive measures	2009 (May)	2010 (April)
13	QLSCD 1 - Cohort 1996 - Data collection 2010	Questionnaires Cognitive measures	2010 (May)	2011 (April)
14	QLSCD 1 - Cohort 1996 - Data collection 2011	Questionnaires Cognitive measures	2011 (May)	2012 (April)
15	QLSCD 1 - Cohort 1996 - Data collection 2012	Questionnaires Cognitive measures	2012 (May)	2013 (April)
16	QLSCD 1 - Cohort 1996 - Data collection 2013	Questionnaires Cognitive measures	2013 (May)	2014 (April)
17	QLSCD 1 - Cohort 1996 - Data collection 2014	Questionnaires Cognitive measures	2014 (May)	2015 (April)

QLSCD 2 - Cohort 2018

The population is composed of babies aged 59 or 62 gestational weeks at the beginning of the data collection period, born between January 23rd and September 5, 2018 to mothers living in 3 selected sociosanitary regions: Montréal, Mauricie–Centre-du-Québec and Montérégie.

Selection Criteria

Newborns

Countries

Canada

Canadian Provinces

Quebec

Territory

Montréal, Mauricie–Centre-du-Québec and Montérégie

Other Criteria

Inclusion: Minimum age: 59 gestational weeks at the beginning of each collection period at time 1
Maximum age: 60 gestational weeks at the beginning of each collection period at time 1
Exclusion: death at birth, family lives outside Quebec permanently or in a region excluded from the study

Sources of Recruitment

General Population

Selected sample

Supplementary Information

Participants were selected from the "Fichier de Naissances Vivantes" in the targeted sociosanitary regions and from the "Paiement de l’allocation aux familles de Retraite Québec". They are thereafter invited to participate.

Sample Size

Number of Participants: 449
Number of Participants with Biological Samples: 449

Data Collection Events

#	Name	Data sources	Start	End
0	QLSCD 2 - Cohort 2018 - Data collection 2018	Questionnaires	2018 (October)	2019 (March)
1	QLSCD 2 - Cohort 2018 - Data collection 2019	Questionnaires	2019 (October)	2020 (March)
2	QLSCD 2 - Cohort 2018 - Data collection 2020	Questionnaires	2020 (October)	2020 (December)
3	QLSCD 2 - Cohort 2018 - Data collection 2021	Questionnaires	2021 (October)	2022 (March)

QLSCD 2 - Cohort 2020-2021

The population is composed of babies aged 60 gestational weeks at the beginning of each data collection period, born between October 1st, 2020 and September 30th, 2021 to mothers living in Quebec, in rural and urban settings and from low socio-economic status.

Selection Criteria

Newborns

Countries

Canada

Canadian Provinces

Quebec

Territory

Bas-Saint-Laurent, Saguenay–Lac-Saint-Jean, Capitale-Nationale, Mauricie-et-Centre-du-Québec, Estrie, Montréal, Outaouais, Abitibi-Témiscamingue, Côte-Nord, Gaspésie–Îles-de-la-Madeleine, Chaudière-Appalaches, Laval, Lanaudière, Laurentides, Montérégie

Other Criteria

Inclusion: 60 gestational weeks at the beginning of each collection period at time 1
Exclusion: Babies whose gestation lasted less than 24 weeks or more than 42 weeks; whose family is living in the the sociosanitary areas of Northern Quebec, Nunavik or the Cree Territory of James Bay and whose mothers are living on Indian reserves

Sources of Recruitment

General Population

Selected sample

Supplementary Information

Participants were selected from the "Fichier de Naissances Vivantes" in the targeted sociosanitary regions and were thereafter invited to participate.

Sample Size

Number of Participants: 8,200
Number of Participants with Biological Samples: 8,200

Data Collection Events

#	Name	Data sources	Data sources - Biosamples	Start	End
0	QLSCD 2 - Cohort 2020-2021 - Data collection 2021	Questionnaires		2021 (May)	2022 (March)
1	QLSCD 2 - Cohort 2020-2021 - Data collection 2022	Questionnaires		2022 (May)	2023 (March)

Participating Studies

Acronym	Name	Study design	Countries

Harmonization Initiatives Included

Acronym	Name

Datasets

Search Variables

Name	Data Collection Events	Variables

Variables Content Summary

Areas of Information Collected per per Population and Data Collection Event

Networks

Acronym	Name	Harmonization Initiatives	Individual Studies

Last Update: 2023-04-18T13:45:43.240

Québec Longitudinal Study of Child Development

Overview

General Design

Access

Marker Papers

Supplementary Information

Documents

Timeline

Populations

Selection Criteria

Sources of Recruitment

Sample Size

Documents

Data Collection Events

Selection Criteria

Sources of Recruitment

Sample Size

Documents

Data Collection Events

Selection Criteria

Sources of Recruitment

Sample Size

Documents

Data Collection Events

Selection Criteria

Sources of Recruitment

Sample Size

Documents

Data Collection Events

Participating Studies

Harmonization Initiatives Included

Datasets

Areas of Information Collected

Variables Content Summary

Areas of Information Collected

Areas of Information Collected per per Population and Data Collection Event

Networks

Québec Longitudinal Study of Child Development

Overview

Isabelle Archambault

Caroline Fitzpatrick

Xavier Saint-Denis

Frank Vitaro

Véronique Dupéré

Richard E. Tremblay

Lise Dubois

Tamarha Pierce

Nancy Illick

General Design

Access

Representative

Marker Papers

Supplementary Information

Documents

Timeline

Populations

QLSCD 1 - Cohort 1998 - Data collection 1998

QLSCD 1 - Cohort 1998 - Data collection 1999

QLSCD 1 - Cohort 1998 - Data collection 2000

QLSCD 1 - Cohort 1998 - Data collection 2001

QLSCD 1 - Cohort 1998 - Data collection 2002

QLSCD 1 - Cohort 1998 - Nutrition Data collection 2002

QLSCD 1 - Cohort 1998 - Data collection 2003

QLSCD 1 - Cohort 1998 - Data collection 2004

QLSCD 1 - Cohort 1998 - Psychomotricity Data collection 2004

QLSCD 1 - Cohort 1998 - Data collection 2005

QLSCD 1 - Cohort 1998 - Psychomotricity Data collection 2006

QLSCD 1 - Cohort 1998 - Data collection 2006

QLSCD 1 - Cohort 1998 - Data collection 2008

QLSCD 1 - Cohort 1998 - Health Data collection 2008-2009

QLSCD 1 - Cohort 1998 - Data collection 2010

QLSCD 1 - Cohort 1998 - Data collection 2011

QLSCD 1 - Cohort 1998 - Data collection 2013

QLSCD 1 - Cohort 1998 - Data collection 2015

QLSCD 1 - Cohort 1998 - Biological Embedding of Childhood Adversity Data collection 2015

QLSCD 1 - Cohort 1998 - Data collection 2017

QLSCD 1 - Cohort 1998 - Mental health Data collection 2018

QLSCD 1 - Cohort 1998 - Data collection 2019

QLSCD 1 - Cohort 1996 - Data collection 1996

QLSCD 1 - Cohort 1996 - Data collection 1997

QLSCD 1 - Cohort 1996 - Data collection 1998

QLSCD 1 - Cohort 1996 - Data collection 1999

QLSCD 1 - Cohort 1996 - Data collection 2001

QLSCD 1 - Cohort 1996 - Data collection 2002

QLSCD 1 - Cohort 1996 - Data collection 2003

QLSCD 1 - Cohort 1996 - Data collection 2004

QLSCD 1 - Cohort 1996 - Data collection 2005

QLSCD 1 - Cohort 1996 - Data collection 2006

QLSCD 1 - Cohort 1996 - Data collection 2007

QLSCD 1 - Cohort 1996 - Data collection 2008

QLSCD 1 - Cohort 1996 - Data collection 2009

QLSCD 1 - Cohort 1996 - Data collection 2010

QLSCD 1 - Cohort 1996 - Data collection 2011

QLSCD 1 - Cohort 1996 - Data collection 2012

QLSCD 1 - Cohort 1996 - Data collection 2013

QLSCD 1 - Cohort 1996 - Data collection 2014

QLSCD 2 - Cohort 2018 - Data collection 2018

QLSCD 2 - Cohort 2018 - Data collection 2019

QLSCD 2 - Cohort 2018 - Data collection 2020

QLSCD 2 - Cohort 2018 - Data collection 2021

QLSCD 2 - Cohort 2020-2021 - Data collection 2021

QLSCD 2 - Cohort 2020-2021 - Data collection 2022

Selection Criteria

Sources of Recruitment

Sample Size

Documents

Data Collection Events

Selection Criteria

Sources of Recruitment

Sample Size

Documents

Data Collection Events

Selection Criteria

Sources of Recruitment

Sample Size

Documents

Data Collection Events