Appendix Table A.1.
Distributions and Correlations of PM Exposure Variables
| Exposure Variables | N | Exposure Distributions | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Mean | Standard Deviation | Minimum | Percentiles | Maximum | ||||||
| 10th | 25th | Median | 75th | 90th | ||||||
| Fixed Cumulative Exposures in WHIMS-MRI | ||||||||||
| Cumulative exposure to PM2.5 (1999–2006) | 1,403 | 12.64 | 2.78 | 5.75 | 10.11 | 10.67 | 12.24 | 14.16 | 16.22 | 22.2 |
| Cumulative exposure to DPM (1996–2005) | 1,403 | 0.44 | 0.33 | 0.01 | 0.14 | 0.24 | 0.35 | 0.55 | 0.83 | 3.93 |
| Fixed Baseline Exposures in WHIMS | ||||||||||
| Exposure to DPM at WHIMS baseline (1996–1998) | 7,112 | 0.54 | 0.38 | 0 | 0.11 | 0.26 | 0.49 | 0.74 | 1 | 5.42 |
| Time-Varying Exposures in WHIMS during Follow-up | ||||||||||
| Time-varying cumulative PM2.5 exposure (1999–2007) | 7,050 | 13.15 | 3.22 | 3.71 | 9.45 | 11.11 | 12.95 | 15.01 | 16.93 | 27.1 |
| Time-varying cumulative DPM exposure (1996–2005) | 7,447 | 0.48 | 0.31 | 0 | 0.16 | 0.27 | 0.43 | 0.62 | 0.84 | 5.12 |
| Pearsons Correlations among PM Exposure Variables | |||||
|---|---|---|---|---|---|
| (1) | (2) | (3) | (4) | (5) | |
| Exposures Used in WHIMS–MRI | |||||
| (1) Baseline cumulative exposure to PM2.5 | 1 | 0.45 | 0.42 | 0.99 | 0.45 |
| (2) Baseline cumulative exposure to DPM | 0.45 | 1 | 0.83 | 0.45 | 0.95 |
| Exposures Used in WHIMS | |||||
| (3) Baseline exposure to DPM | 0.42 | 0.83 | 1 | 0.4 | 0.93 |
| (4) Summarized time-varying cumulative PM2.5 exposurea | 0.99 | 0.45 | 0.4 | 1 | 0.42 |
| (5) Summarized time-varying cumulative DPM exposurea | 0.45 | 0.95 | 0.93 | 0.42 | 1 |
a Individually summarized exposure aggregating all time-varying annual exposures before censoring for the analyses on dementia.