Table 3.
Treatment efficacy in reducing PM2.5 and PNCs in ARTIS homes from the pre- to post-intervention winter.
| Pre-intervention wintera | Post-intervention winterb | % change, relative to placebo (95%CI)c | ||||
|---|---|---|---|---|---|---|
| N | median (range) | N | median (range) | % change in geometric mean concentrationsc | ||
| PM2.5 (μg/m3) | ||||||
| filter | 42 | 17.1 (6.1, 163.1) | 35 | 6.5 (0.7, 65.6) | −69* | −66 (−77, −50) |
| wood stoved | 16 | 40.7 (8.7, 86.8) | 15 | 32.4 (6.1, 138.4) | −9 | 0 (−40, 65) |
| placebo | 40 | 16.1 (3.9, 508.2) | 38 | 16.9 (2.4, 163.2) | −9 | ref |
| PM2.5 max (μg/m3) | ||||||
| filter | 42 | 370.6 (30.9, 16424.2) | 35 | 193.9 (6.1, 3818.2) | −54* | −52 (−73, −14) |
| wood stoved | 16 | 936.4 (48.5, 4539.4) | 15 | 709.1 (23.0, 1921.2) | −30 | −28 (−66, 56) |
| placebo | 40 | 347.0 (14.6, 18181.8) | 38 | 351.2 (26.1, 6363.6) | −3 | ref |
| PNC (particles/cm3) | ||||||
| 0.3−0.49 μm | ||||||
| filter | 40 | 35.9 (4.4, 179.6) | 34 | 13.4 (0, 90.0) | −75* | −67 (−83, −33) |
| wood stoved | 16 | 66.5 (18.2, 198.9) | 15 | 71.2 (17.4, 247.5) | −4 | 29 (−47, 215) |
| placebo | 40 | 38.2 (13.3, 275.2) | 37 | 38.1 (0, 368.7) | −25 | ref |
| 0.50−0.99 μm | ||||||
| filter | 40 | 4.1 (0.8, 30.9) | 34 | 1.7 (0, 14.9) | −75* | −62 (−84, −9) |
| wood stoved | 16 | 8.5 (1.6, 24.1) | 15 | 7.7 (2.2, 30.9) | −12 | 38 (−54, 315) |
| placebo | 40 | 5.0 (1.8, 34.0) | 37 | 4.9 (0, 39.9) | −36 | ref |
| 1.0−2.49 μm | ||||||
| filter | 40 | 0.6 (0.1, 4.3) | 34 | 0.2 (0, 1.8) | −76* | −53 (−80, 7) |
| wood stoved | 16 | 0.9 (0.3, 3.4) | 15 | 0.6 (0.2, 3.6) | −15 | 64 (−44, 378) |
| placebo | 40 | 0.5 (0.2, 3.9) | 37 | 0.5 (0, 1.9) | −48* | ref |
| fine | ||||||
| filter | 40 | 40.6 (5.3, 192.3) | 34 | 15.5 (0, 106.1) | −75* | −66 (−83, −31) |
| wood stoved | 16 | 79.0 (20.4, 214.8) | 15 | 82.6 (20.3, 279.0) | −5 | 29 (−47, 216) |
| placebo | 40 | 43.8 (15.5, 303.6) | 37 | 43.9 (0, 409.3) | −27 | ref |
| coarse | ||||||
| filter | 40 | 0.3 (0.1, 1.5) | 34 | 0.2 (0, 0.6) | −72* | −35 (−71, 46) |
| wood stoved | 16 | 0.3 (0.1, 2.2) | 15 | 0.3 (0.1, 1.6) | −19 | 91 (−33, 447) |
| placebo | 40 | 0.3 (0.1, 3.6) | 37 | 0.2 (0, 1.9) | −57* | ref |
| CO (ppm) | ||||||
| filter | 41 | 0.1 (0, 13.5) | 35 | 0.3 (0, 1.2) | 78 | −13 (−75, 200) |
| wood stoved | 16 | 0.6 (0, 6.5) | 15 | 0 (0, 1.1) | −76* | −87 (−97, −33) |
| placebo | 40 | 0.1 (0, 6.5) | 38 | 0.2 (0, 1.6) | 55 | ref |
P < 0.05.
PM2.5, PNC, and CO data were available for 98, 96, and 97 homes, respectively during the pre-intervention winter.
PM2.5, PNC, and CO data were available for 88, 86, and 88 homes, respectively during the post-intervention winter.
Linear mixed model analyses evaluating modification of pre- to post-intervention changes in indoor air quality by treatment assignment. PM2.5, PNCs, and CO were log-transformed, and results reported as the percent change in geometric mean concentrations.
Wood stove refers to the wood stove changeout intervention arm, which was discontinued prior to enrollment of the final cohort of homes due to a lack of efficacy in reducing indoor PM2.5 concentrations.