Table 2.

Baseline characteristics.

		Child obesity rate, n(%)		P-value by using chi-square test
		No	Yes
Grandchild care	Yes	5,429 (78.04%)	1,528 (21.96%)	Pearson chi2(1)=12.41, P = 0.000
	No	17,130 (85.89%)	2,815 (14.11%)
Basic Medical insurance	Insured	16,935 (84.32%)	3,150 (15.68%)	Pearson chi2(1) = 234.77, P = 0.000
	Uninsured	5,624 (82.50%)	1,193 (17.50%)
Commercial medical insurance	Participated = 1	3,524 (86.86%)	533 (13.14%)	Pearson chi2(1) = 31.89, P = 0.000
	Unparticipated = 0	19,035 (83.32%)	3,810 (16.68%)