Table 2. Participant characteristics and household environments overall and for children with developmentally on-track data.

Participants’ characteristics	Totaln=6557 (100%)		Developmentally on trackn=5328 (81.3%)		P value*
	n	% (column)	n	% (row)
Age (months)					0.61
24–35	2148	32.7	1739	80.9
36–47	2191	33.4	1758	80.3
48–59	2218	33.9	1832	82.6
Sex					<0.001
Boy	3562	54.3	2788	78.3
Girl	2995	45.7	2540	84.8
Region					<0.001
Bangkok	538	8.2	482	89.5
Central	1706	26.0	1416	83.0
North	1161	17.7	877	75.5
Northeast	2029	31.0	1602	79.0
South	1124	17.1	951	84.7
Residency					0.03
Urban	2631	40.1	2207	83.9
Rural	3926	59.9	3122	79.5
Maternal education					<0.001
Below secondary education	2055	31.3	1538	74.9
Secondary education	2722	41.5	2214	81.3
Above secondary education	1780	27.2	1576	88.5
Household wealth (quintile)					0.002
1	1415	21.6	1104	78.0
2	1314	20.0	1022	77.7
3	1323	20.2	1084	82.0
4	1433	21.8	1171	81.7
5	1073	16.4	948	88.4
Living arrangements					0.06
Living with neither mother nor father	1427	21.8	1094	76.7
Living with either mother or father	1426	21.8	1188	83.3
Living with both mother and father	3704	56.4	3047	82.3
Language used at home					0.24
Thai	5942	90.6	4845	81.5
Non-Thai	615	9.4	483	78.6
Number of books at home					<0.001
<3	3562	54.3	2729	76.6
3–9	2197	33.5	1868	85.0
≥10	798	12.2	731	91.6
Screen time duration (hour/day)					<0.001
0	2704	41.2	2066	76.4
≥1	3853	58.8	3262	84.7

P-value in bold indicates statistical significance.

^*Bivariate association between categorical variables and developmentally on track was examined via χ2 analyses (p<0.05=statistical significance).