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. Author manuscript; available in PMC: 2017 Nov 1.
Published in final edited form as: Int J Hyg Environ Health. 2016 Jul 19;219(8):850–856. doi: 10.1016/j.ijheh.2016.07.012

Table 3.

Mediation analysis of cadmium effect on the smoking-cataract pathway by using causal inference approacha.

Smoking Status ORNDE ORNIE Total Effect Proportion Mediated
<20 pack-years vs. non-smokers 1.13 1.14 1.28 0.54
≥20 pack-years vs. non-smokers 1.28 1.29 1.65 0.57
Ever smoker vs. non-smoker 1.20 1.21 1.45 0.55
a

NDE: Natural Direct Effect; NIE: Natural Indirect Effect; Total Effect: combination of Natural Direct and Indirect Effect; Proportion Mediated: the Proportion of NIE in Total Effect (see Appendix for details). Calculation based on Model C using CAS+CA method.