Table 5.

Summary table of the policy effect on absolute and relative inequalities in health

Method	Estimated policy effect on absolute health inequalitya(reduced rate difference in % points, [95% CI])	Estimated policy effect on relative health inequalityb (reduced rate ratio, in %, [95% CI])
1. Regression adjustment	1.97 [1.19, 2.76]	12.20 [4.49, 19.90]
2. Matching	1.89 [1.77, 2.02]	11.60 [8.99, 14.20]
3. Difference-in-differences	1.85 [0.88, 2.82]	11.33 [1.37, 21.29]
4. Fixed effects	1.82 [1.28, 2.36]	12.26 [5.45, 19.08]
5. Instrumental variable	2.02 [1.34, 2.69]	12.62 [6.07, 19.17]
6. Regression discontinuity	not comparable	not comparable
7. Interrupted time-series	1.85 [1.45, 2.26]	11.53 [6.05, 17.00]
Real policy effect	1.86	11.25
Simple before-and-after comparison	0.86	−22.03

^aWe calculated the prevalence of people having poor health in each educational group following the real policy implementation and the predicted prevalence if leaving out the term for the policy effect (when there was no policy). The reported numbers represent the absolute reduction of the rate difference that can be attributed to the policy

^bThe reported numbers represent the relative reduction of the rate ratio (RR) calculated as follows: (RR_{without policy} – RR_with policy)/(RR_{without policy} ‐ 1) * 100