Table 1

Cohort profiles*

Cohort
country/region
baseline year
Age at baseline
and cohort follow-up†
Sampling methodologySample size (N)
baseline and 10/11 years
complete case rate‡ (%)
Weighting and imputation for attrition
MCS38
UK
2000
Baseline (Sweep 1): 9 months
Sweep 2: 3 years
Sweep 3: 5 years
Sweep 4: 7 years
Sweep 5: 10/11 years
  • All children born between 1 September 2000 and 31 August 2001 (for England and Wales), and between 24 November 2000 and 11 January 2002 (for Scotland and Northern Ireland), alive and living in UK at age 9 months, and eligible to receive child benefit at that age

  • Eligibility based on government child benefit records (ie, nearly universal coverage); asylum seekers not eligible

  • Subgroups intentionally oversampled (living in disadvantaged areas, ethnic minorities)

Baseline: 18 552
10/11 years (Sweep 5): 13 354
Complete Cases: 71.6%
  • Weights applied

  • Imputation for differential attrition

ABIS39
Southeast Sweden
1997 to 1999
Baseline (Sweep 1): Birth
Sweep 2: 1 year
Sweep 3: 2.5 years
Sweep 4: 5 years
Sweep 5: 8 years
Sweep 6: 10–12 years
  • All children born between 1 October 1997 and 30 September 1999 in a defined region in southeast of Sweden were invited

Baseline: 17 055
Diagnoses available from Patient Register at age 11 years for 16 365
Complete Cases: 96.0%
  • No weights applied

  • No imputation

LSAC K40
Australia
2004
Baseline (Wave 1): 4–5 years
Wave 2: 6–7 years
Wave 3: 8–9 years
Wave 4: 10–11 years
  • National sample using two-stage random sampling design: (1) random selection of 10% of postcodes, stratified by state and urban/rural locations, (2) random selection of in-age children within those postcodes from Medicare (universal healthcare) database

  • Excluded remote postcodes and postcodes with <20 children (n=874 postcodes, 3.2% of population)

Baseline: 4983
10–11 years (Wave 4): 4164
Complete cases: 83.6%
  • Weights applied to account for differential attrition

  • No imputation

GenR41
Rotterdam,
The Netherlands
2002 to 2006
Baseline (Wave 1): Birth-4 years
(‘Preschool Period’: 2 months, 6 monthss, 1 year, 1.5 years, 2 years, 3 years, 4 years)
Wave 2: 5–6 years
Wave 3: 9–10 years
  • Pregnant women who expected to deliver between April 2002 and January 2006, living in Rotterdam, who visited a midwife or obstetrician were eligible for participation and contacted by GenR staff

Baseline: 9749
5–6 years (Wave 2): 8305
Complete cases: 85.2%
  • Weights applied to account for differential attrition

  • No imputation

NLSCY42
Canada
2000–2004
Baseline: birth to 11 months
Cycle 2: 2 years
Cycle 3: 4 years
Cycle 4: 6 years
Cycle 5: 8 years
Cycle 6: 10 years
  • Sampling conducted in collaboration with Canada’s Labour Force Survey and National Population Health Survey

  • Sampling stratified by province to select a representative sample of children in Canada

Baseline: 2227
10 years (cycle 6): 1356
Complete cases: 60.9%
  • Weights applied to account for differential attrition and to weight back to population

  • No imputation

USNLSY43
USA
1988 to 1996
Baseline: Birth
Round 2: 2 years
Round 3: 4 years
Round 4: 6 years
Round 5: 8 years
Round 6: 10 years
  • Original NLSY79 cohort was cross-sectional, population representative sample born between January 1958 and December 1964; subsamples intentionally included Hispanic or Latino, black, economically disadvantaged nonblack/non-Hispanic, and military personnel

  • NLSY79 Child and Young Adult cohort follows offspring born to female respondents of the original NLSY79 cohort. Analytical sample for present study was limited to children born between 1988 and 1996.

Baseline: 3657
10 years (round 6): 2578
Complete cases: 70.5%
  • Weights applied to account for differential attrition and to weight back to the population

  • No imputation

  • *Factual content about Cohort Profiles is similarly provided across all EPOCH Collaborative Group publications.

  • †Follow-ups specific to timeframe of present analyses (birth to age 10); several cohorts are ongoing. Follow-up terminology preserved (eg, wave, sweep); when no term given, ‘wave’ was used for clarity.

  • ‡Sample size at age 10 years was based on complete cases with all variables observed to yield conservative complete case rate estimate.

  • ABIS, All Babies in South-East Sweden; EPOCH, Elucidating Pathways Of Child Health inequalities; GenR, Generation R; LSAC K, Longitudinal Study of Australian Children K-cohort; MCS, Millennium Cohort Study; NLSCY, National Longitudinal Study of Children and Youth ; USNLSY, National Longitudinal Survey of Youth Children and Young Adults.