Table 3.

Trends in age-standardized prevalence (95 % confidence intervals) of childhood obesity according to household income and urbanity among South Korean boys and girls aged 10–19

	1998–2001	2010–2012	P for trends*	P for interaction**		1998–2001	2010–2012	P for trends*	P for interaction**
Boys					Girls
IOTF criteria	3.4 (2.5–4.3)	4.8 (3.5–6.1)	0.0751		IOTF criteria	1.3 (0.7–1.8)	2.7 (1.6–3.9)	0.0141
Household income					Household income
Low	3.2 (1.7–4.7)	4.1 (2.3–5.9)	0.4392	0.4249	Low	2.1 (0.9–3.4)	3.6 (1.5–5.6)	0.211	0.8101
Middle	3.3 (1.9–4.8)	3.7 (1.5–5.8)	0.8356		Middle	0.8 (0.1–1.5)	2.0 (0.2–3.7)	0.2291
High	3.5 (1.9–5.1)	6.5 (3.8–9.2)	0.0435		High	1.1 (0.1–2.0)	2.2 (0.6–3.8)	0.1393
P-value for trend***	0.9189	0.1771			P-value for trend***	0.1519	0.245
Urbanity					Urbanity
Rural	3.8 (1.8–5.7)	1.9 (0.2–3.6)	0.171	0.0117	Rural	2.6 (1.0–4.3)	8.1 (2.7–13.5)	0.1346	0.3353
Urban	3.3 (2.3–4.3)	5.4 (3.8–6.9)	0.0205		Urban	1.0 (0.4–1.5)	2.1 (1.1–3.1)	0.0536
P-value****	0.6957	0.0197			P-value****	0.0342	0.0387
KCDC 2007	5.2 (4.0–6.4)	6.9 (5.3–8.5)	0.1427		KCDC 2007	5.9 (4.5–7.2)	7.8 (6.0–9.6)	0.101
Household income					Household income
Low	4.3 (2.5–6.0)	6.4 (3.8–8.9)	0.2611	0.6890	Low	8.6 (5.6–11.5)	9.3 (6.3–12.3)	0.7375	0.9588
Middle	4.9 (3.0–6.7)	5.4 (2.9–7.9)	0.8176		Middle	3.7 (2.1–5.4)	6.2 (3.3–9.1)	0.1703
High	6.2 (3.8–8.6)	8.7 (5.6–11.9)	0.2113		High	5.6 (3.5–7.7)	7.3 (4.3–10.2)	0.3357
P-value for trend***	0.2758	0.2521			P-value for trend***	0.1134	0.2516
Urbanity					Urbanity
Rural	5.7 (3.3–8.1)	3.9 (1.2–6.7)	0.2371	0.0356	Rural	7.1 (4.5–9.7)	13.5 (7.2–19.8)	0.1686	0.3428
Urban	5.1 (3.8–6.4)	7.4 (5.6–9.2)	0.0526		Urban	5.6 (4.1–7.2)	7.2 (5.4–9.0)	0.2448
P-value****	0.6814	0.0484			P-value****	0.4082	0.1444

*P-values for time trends between 1998–2001 and 2010–2012

**P-values for the interactions between time period and household income and between time period and urbanity

***P-values for linear trends among household income groups

****P-values for between-group (urban-rural areas) differences