Table 1. Baseline characteristics by parental education for the Hong Kong ‘Children of 1997’ birth cohort, using imputed data.

	Highest parental education
Characteristics	≥Grade 12(n = 1870)	Grade 10–11(n = 3144)	≤Grade 9(n = 2238)
Boys (%)	52.3	52.7	51.2
Household income at birth (%)
1st Quintile	3.6	15.6	41.2
2nd Quintile	4.7	21.5	32.9
3rd Quintile	13.7	24.6	18.6
4th Quintile	25.2	25.6	6.2
5th Quintile	52.8	12.7	1.1
Mother’s place of birth (%)
Hong Kong	79.0	65.8	35.5
Rest of China/other	21.0	34.2	64.5