Table 3.

Trends in absolute and relative socioeconomic inequality in age-standardized smoking prevalence by income level

				Trends by absolute measure (PD, SII)						Trends by relative measure (PR, RII)
				KNHANES		KCHS		SSSK		KNHANES		KCHS		SSSK
				(2009, 2010) to (2015, 2016)	(2013, 2014) to (2015, 2016)	2009 to 2015	2014 to 2015	2008 to 2016	2014 to 2016	(2009, 2010) to (2015, 2016)	(2013, 2014) to (2015, 2016)	2009 to 2015	2014 to 2015	2008 to 2016	2014 to 2016
Men (age, y)
	30-59
		Income tertile
			PD/PR	↘	↘	↘	↘	↔	↘	↘	↔	↔	↔	↗	↘
			SII/RII	↘	↘	↘	↘	↗	↘	↘	↔	↔	↔	↗	↘
	≥60
		Income tertile
			PD/PR			↘	↘	↘	↘			↗	↗	↗	↘
			SII/RII			↘	↘	↘	↘			↗	↗	↗	↘
Women (age, y)
	30-59
		Income tertile
			PD/PR	↘	↗	↘*	↗	↘*	↘	↗	↗	↘*	↗	↘	↘
			SII/RII	↗	↗	↘*	↗	↘*	↘	↘	↗	↘*	↗	↘	↘
	≥60
		Income tertile
			PD/PR			↘*	↗	↘	↗			↗	↗	↗	↗
			SII/RII			↘*	↗	↘	↗			↗	↗	↗	↗

Data from the Korea National Health and Nutrition Examination Survey (KNHANES), the Korea Community Health Survey (KCHS), and the Social Survey of Statistics Korea (SSSK).

↗: increased, ↘: decreased, ↔: neither increased nor decreased.

PD, prevalence difference; PR, prevalence ratio; SII, slope index of inequality; RII, relative index of inequality.

^*p<0.05.