Table 4.

Sodium-Potassium Ratio in South Korea, 1998, 2005 and 2009

Demographic group	1998	2005	2009	P value1
Age groups
2-6 y	1.50	1.46	1.27	<0.001
7-12 y	1.65	1.65	1.49	<0.05
13-18 y	1.88	1.88	1.73	<0.05
19-39 y	1.94	1.90	1.81	<0.001
40-59 y	1.96	1.86	1.74	<0.001
60 y+	2.00	1.93	1.68	<0.001
Gender
Male	1.91	1.87	1.80	<0.001
Female	1.86	1.81	1.62	<0.001
Adults (≥19 y) education
<High school diploma	2.04	1.92	1.78	<0.001
≥High school diploma	1.94	1.88	1.74	<0.001
Income as percentage of poverty (%)2
Low (<120%)	1.96	1.84	1.75	<0.001
Middle (120-250%)	1.85	1.78	1.73	<0.01
High (≥250%)	1.78	1.76	1.67	<0.05
Region
Large City	1.87	1.74	1.63	<0.001
Small City	1.85	1.87	1.63	<0.001
Rural	1.96	1.84	1.72	<0.001
Total	1.88	1.84	1.71	<0.001

¹Student t-test comparing mean per capita sodium-potassium ratio between 1998 and 2009

²Calculated values based on poverty threshold of each year.