Table 2:
Association between metalworking fluids and ESRD: Exposure modeled with cubic splines in standard Cox proportional hazards regression and competing risk regression, among all Males.
| Cumulative exposure | Standard Cox | Fine and Gray | ||||||
|---|---|---|---|---|---|---|---|---|
| mg/m3-yr, | ESRD n=501† | ESRD n=501† | Death n=13,434 | |||||
| MWF type | Percentile* | 15-yr lag | HR‡ | 95% CI | sHR‡ | 95% CI | sHR‡ | 95% CI |
| Straight | 60 | 1.44 | 1.00 | 0.96, 1.04 | 1.01 | 0.97, 1.05 | 1.00 | 0.99, 1.01 |
| 70 | 2.12 | 1.00 | 0.94, 1.06 | 1.01 | 0.96, 1.07 | 1.00 | 0.99, 1.01 | |
| 80 | 4.26 | 1.00 | 0.88, 1.12 | 1.03 | 0.92, 1.15 | 1.01 | 0.99, 1.03 | |
| 90 | 11.91 | 0.99 | 0.75, 1.32 | 1.07 | 0.83, 1.40 | 1.02 | 0.97, 1.07 | |
| Soluble | 60 | 9.33 | 0.99 | 0.86, 1.14 | 1.08 | 0.93, 1.26 | 1.00 | 0.97, 1.02 |
| 70 | 13.30 | 0.98 | 0.81, 1.19 | 1.11 | 0.91, 1.35 | 1.00 | 0.96, 1.03 | |
| 80 | 18.67 | 0.96 | 0.75, 1.22 | 1.13 | 0.88, 1.45 | 1.00 | 0.95, 1.04 | |
| 90 | 28.74 | 0.90 | 0.67, 1.20 | 1.11 | 0.83, 1.50 | 1.00 | 0.94, 1.05 | |
| Synthetic | 60 | 0.84 | 0.92 | 0.81, 1.05 | 0.96 | 0.85, 1.09 | 0.99 | 0.97, 1.01 |
| 70 | 1.51 | 0.87 | 0.70, 1.08 | 0.93 | 0.76, 1.15 | 0.99 | 0.96, 1.03 | |
| 80 | 1.81 | 0.85 | 0.66, 1.10 | 0.92 | 0.72, 1.18 | 0.99 | 0.95, 1.03 | |
| 90 | 2.90 | 0.79 | 0.56, 1.14 | 0.89 | 0.64, 1.26 | 0.99 | 0.93, 1.04 | |
Abbreviations: CI, confidence interval; ESRD, end-stage renal disease; HR, hazard ratio; MWF, metalworking fluids
*
For each MWF type, a restricted cubic spline was used to estimate the HR; we present the HR at specific points along the spline, based on percentile of exposure for the exposed cases
†
Distribution of ESRD cases and person-time in each spline are shown in Figures 1A and 1B
‡
Adjusted for age, race, calendar year, year hired, plant, other MWFs, and with time since hire as the analytic timeline