Table 4. Forward Stepwise Multivariate Analysis of the Association of Indoor PM2.5 With Dry Eye Metricsa .
| Variable | OSDI | Dry eye signs | ||
|---|---|---|---|---|
| Inflammation | Schirmer score | Meibomian gland dropout | ||
| PM2.5, μg/m3b | 1.59 (0.58 to 2.59)c | 0.06 (0.02 to 0.11)c | −0.39 (−0.75 to −0.03)d | 0.07 (0.01 to 0.13)d |
| Depression | 11.38 (1.35 to 21.41)d | NA | NA | NA |
| Arthritis | 14.69 (5.19 to 24.20)c | NA | NA | NA |
| Weight | NA | 0.01 (0 to 0.01)d | NA | NA |
| Age | NA | 0.03 (0.01 to 0.05)c | NA | 0.03 (0 to 0.05)d |
| Hypercholesteremia | NA | NA | −3.64 (−7.03 to −0.26)d | NA |
| Constant | 9.49 (−0.21 to 19.18)e | −1.74 (−3.47 to −0.01)d | 16.72 (13.93 to 19.52)c | −0.24 (−1.79 to 1.32) |
| No. of observations | 70 | 71 | 71 | 71 |
| Total variability explained, R2 | 0.29 | 0.21 | 0.12 | 0.13 |
Abbreviations: NA, not applicable; OSDI, Ocular Surface Disease Index; PM2.5, airborne particulate matter of 2.5 μm or less in aerodynamic diameter.
a
Unless otherwise indicated, data are expressed as β regression coefficient (95% CI).
b
PM2.5 = PM2.5 instrumented on RH [relative humidity] = β × RH.
c
P < .01, not adjusted for multiple analyses.
d
P < .05, not adjusted for multiple analyses.
e
P < .10, not adjusted for multiple analyses.