Table 2.

Risk factors of early childhood caries reported by surveys in Hong Kong

Risk factors	1993	1999	2009	2016
	Wei et al16 (N=1,105)	Chu et al17 (N=607)	Chu et al19 (N=557)	Chen et al21 (N=505)
Monthly household income	Yes	Yes	Yes	Yes
Tooth brushing frequency	Yes	Yes	No	No
Fathers’ profession	Yes	–	–	–
Place of birth	–	Yes	Yes	No
Response of dental care to children’s caries	–	Yes	–	–
Dental visit pattern	–	Yes	Yes	Yes
Mother’s education level	–	Yes	Yes	Yes
Father’s education level	–	Yes	Yes	No
Age tooth brushing started	–	–	Yes	No
Snacking frequency	–	–	Yes	Yes
Parents’ dental knowledge level	–	Yes	Yes	Yes
Parenthood	–	–	Yes	No
Primary caregiver	–	–	Yes	Yes

Notes: Yes: the risk factor was significantly associated with ECC; No: the risk factor was not significantly associated with ECC; –: the risk factor was not reported in the study.

Abbreviation: ECC, early childhood caries.