Table 3:
Block-level characteristics for patient and non-patient blocks, and associations with pulmonary NTM counts by census block1
| Predictor variable | Level | Block Level Characteristics | Unadjusted Model2 | ||
|---|---|---|---|---|---|
| Patient Blocks (n=473) | Non-Patient Blocks (n=13,022) | Mean Count (95% Confidence Interval) | p-value | ||
| Hydric soil | |||||
| No. (% of blocks) | >20% | 119 (4.4%) | 2,619 (95.6%) | 17.3% (−5.0%, 44.9%) | 0.1 |
| ≤20% | 354 (3.3%) | 10,403 (96.7%) | Reference | ||
| Acidic soil | |||||
| No. (% of blocks) | >50% | 308 (3.1%) | 9,475 (96.2%) | 9.7% (−14.8%, 41.3%) | 0.5 |
| ≤50% | 165 (4.5) | 3,547 (95.5%) | Reference | ||
| Cultivated crops % | |||||
| mean (SD) | 0.7% (3.6%) | 0.8% (4.7%) | 0.8% (−1.5%, 3.2%) | 0.5 | |
| Dirt road density (km/km2) | |||||
| mean (SD) | 268 (1,950) | 483 (3,774) | 0% (0%, 0%) | 0.7 | |
| Deciduous forest % | |||||
| mean (SD) | 10.2% (15.2%) | 9.9% (17.2%) | 0.5% (−0.1%, 1.1%) | 0.1 | |
| Evergreen forest % | |||||
| mean (SD) | 6.0% (8.8%) | 5.8% (11.2%) | 0.2% (−0.7%, 1.2%) | 0.6 | |
| Grassland % | |||||
| mean (SD) | 5.2% (10.2%) | 6.4% (13.7%) | −0.1% (−1.0%, 0.7%) | 0.7 | |
| Wetlands % | |||||
| mean (SD) | 1.5% (5.2%) | 1.5% (6.2%) | −1.1% (−2.8%, 0.5%) | 0.2 | |
| Open water % | |||||
| mean (SD) | 0.4% (1.7%) | 0.2% (1.4%) | 5% (−0.1%, 11.2%) | 0.1 | |
| Public drinking water supply | |||||
| No. (% of blocks) | >50% households | 308 (3.4%) | 8,738 (96.6%) | 10.6% (−8.5%, 33.6%) | 0.3 |
| ≤50% households | 165 (4.5) | 4,284 (96.3%) | Reference | ||
| Impervious surface % | |||||
| mean (SD) | 32.7% (27.4%) | 34.0% (31.51%) | −0.2% (−0.6%, 0.1%) | 0.1 | |
| Paved road density (km/km2) | |||||
| mean (SD) | 21,083 (16,413) | 29,716 (24,126) | 0% (0%, 0%) | 0.4 | |
| Population density (people/km2) | |||||
| mean (SD) | 1,350 (1,205) | 1,241 (1,269) | 0% (0%, 0%) | 0.005 | |
| Median building value, per $100,000 USD | |||||
| mean (SD) | 1.8 (1.1) | 1.7 (1.20) | −1.4% (−9.6%, 7.6%) | 0.8 | |
| Median age in years | |||||
| mean (SD) | 41.0 (11.1) | 40.5 (11.2) | 3.7% (2.9%, 4.5%) | <.0001 | |
| Female % | |||||
| mean (SD) | 52.0% (7.2%) | 51.4% (10.4%) | 1.5% (0%, 3.1%) | 0.05 | |
| Race | |||||
| White | 62.9% (29.7%) | 65.0% (32.4%) | 0.2% (−0.1%, 0.5%) | 0.3 | |
| County | |||||
| No. (%) | |||||
| Durham | 148 (5.0%) | 2,789 (95.0%) | 183.7% (90.2%, 323.2%) | <.0001 | |
| Orange | 85 (4.9%) | 1,663 (95.1%) | 171.8% (58.5%, 366.1%) | 0.0003 | |
| Wake | 240 (2.7%) | 8,570 (97.3%) | Reference | ||
1
excludes blocks with zero total population and non-single-family residences
2
included an offset term for population size and a two-dimensional spline smoothing function of geographic coordinates as a single covariate