Table 4.
The hazard ratio (HR) associated with 1-level increase in education (total effect), decomposed into mediated effect (natural indirect effect) and direct effect (natural direct effect) for women
| White women (n=4964) | Black women (n=3800) | |||||
|---|---|---|---|---|---|---|
| Education levels and effect |
HR | (95%CI) | % mediated |
HR | (95%CI) | % mediated |
| Mediator: Substantive complexity of work | ||||||
| High school graduate vs. <high school | ||||||
| Natural direct effect | 0.98 | (0.92, 1.05) | 0.93 | (0.86, 1.00) | ||
| Natural indirect effect | 1.00 | (0.97, 1.04) | -- a | 0.98 | (0.94, 1.02) | -- |
| Total effect | 0.99 | (0.92, 1.06) | 0.91 | (0.83, 0.98) | ||
| Some college vs. high school graduate | ||||||
| Natural direct effect | 0.92 | (0.77, 1.11) | 0.80 | (0.65, 0.98) | ||
| Natural indirect effect | 0.90 | (0.82, 0.99) | 54.8% | 0.96 | (0.84, 1.10) | -- |
| Total effect | 0.83 | (0.72, 0.96) | 0.76 | (0.66, 0.88) | ||
| College graduate vs. some college | ||||||
| Natural direct effect | 0.94 | (0.89, 0.99) | 0.93 | (0.88, 0.99) | ||
| Natural indirect effect | 0.95 | (0.92, 0.99) | 42.6% | 0.99 | (0.93, 1.04) | -- |
| Total effect | 0.90 | (0.85, 0.95) | 0.92 | (0.86, 0.99) | ||
| Graduate degree vs. College | ||||||
| Natural direct effect | 0.93 | (0.88, 0.99) | 0.94 | (0.88, 1.00) | ||
| Natural indirect effect | 0.94 | (0.90, 0.99) | 44.1% | 0.99 | (0.93, 1.06) | -- |
| Total effect | 0.88 | (0.82, 0.94) | 0.93 | (0.84, 1.02) | ||
| Mediator: Hazardous working conditions | ||||||
| High school graduate vs. <high school | ||||||
| Natural direct effect | 0.93 | (0.89, 0.97) | 0.92 | (0.88, 0.97) | ||
| Natural indirect effect | 1.00 | (0.99, 1.00) | -- | 1.00 | (0.99, 1.01) | -- |
| Total effect | 0.93 | (0.88, 0.97) | 0.92 | (0.87, 0.97) | ||
| Some college vs. high school graduate | ||||||
| Natural direct effect | 0.80 | (0.70, 0.92) | 0.78 | (0.67, 0.90) | ||
| Natural indirect effect | 1.00 | (0.98, 1.02) | -- | 0.99 | (0.96, 1.02) | -- |
| Total effect | 0.80 | (0.70, 0.91) | 0.77 | (0.67, 0.89) | ||
|
College graduate vs. some college | ||||||
| Natural direct effect | 0.93 | (0.89, 0.97) | 0.92 | (0.87, 0.96) | ||
| Natural indirect effect | 1.00 | (0.99, 1.01) | -- | 1.00 | (0.98, 1.01) | -- |
| Total effect | 0.93 | (0.89, 0.97) | 0.91 | (0.87, 0.96) | ||
| Graduate degree vs. College | ||||||
| Natural direct effect | 0.93 | (0.89, 0.97) | 0.92 | (0.87, 0.96) | ||
| Natural indirect effect | 1.00 | (0.99, 1.01) | -- | 1.00 | (0.98, 1.01) | -- |
| Total effect | 0.93 | (0.89, 0.98) | 0.91 | (0.87, 0.96) | ||
Notes. Age, region, and working status at the time of NIOSH module are adjusted for in all models.
a
%mediated is not calculated because the natural indirect effect is not significant.