Association of ZIP code, county and participant characteristics with recent homelessness among people who inject drugs from 19 US metro areas in 2009
| Univariate model OR (95% CI) | Multivariable model adjusted OR (95% CI)* | |
| Intercept | 19.58 (1.13 to 339.80) | |
| Region | ||
| Northeast (reference) | 1.00 | |
| South | 1.19 (0.73 to 1.93) | — |
| Midwest | 0.71 (0.33 to 1.55) | — |
| West | 1.33 (0.77 to 2.28) | — |
| Metropolitan statistical area (n=19) | ||
| Random intercept variance | 0.06 (0 to 2.61) | 0.06 (0 to 2.00) |
| County (n=51) | ||
| Random intercept variance | 0.26 (0.10 to 0.70) | 0.21 (0.07 to 0.69) |
| Percent unaffordable rental units among low-income households | 0.97 (0.94 to 1.01) | 0.99 (0.96 to 1.02) |
| Average number of months that applicants were on waiting lists for assisted housing | 1.00 (0.98 to 1.01) | — |
| ZIP code (n=937) | ||
| Random intercept variance | 0.31 (0.23 to 0.43) | 0.17 (0.11 to 0.26) |
| Economic deprivation | 0.98 (0.95 to 1.02) | |
| Gentrification | 1.13 (1.07 to 1.18) | 1.11 (1.04 to 1.17) |
| Participant characteristics | ||
| Current age | 0.97 (0.96 to 0.97) | 0.98 (0.97 to 0.98) |
| Sex (1=male) | 0.88 (0.80 to 0.98) | 0.81 (0.73 to 0.91) |
| Race/ethnicity | ||
| White (reference) | 1.00 | 1.00 |
| Black | 0.66 (0.58 to 0.75) | 0.76 (0.66 to 0.87) |
| Latino | 0.87 (0.75 to 1.01) | 0.83 (0.71 to 0.97) |
| Annual income (US$5000 vs more) | 0.48 (0.44 to 0.53) | 0.48 (0.44 to 0.53) |
| Full-time employment | 0.34 (0.27 to 0.42) | 0.38 (0.30 to 0.49) |
| Incarceration | 2.19 (1.98 to 2.42) | 1.84 (1.65 to 2.05) |
| Daily injection (vs less than daily) | 1.23 (1.10 to 1.37) | 1.18 (1.04 to 1.32) |
| Binge drinking | 1.51 (1.38 to 1.66) | 1.30 (1.18 to 1.44) |
| Non-injection drug use | 1.41 (1.27 to 1.57) | 1.23 (1.10 to 1.37) |
| Type of sexual partner in the past 12 months | ||
| None | 1.00 | 1.00 |
| Main | 1.15 (0.82 to 1.60) | 1.14 (0.81 to 1.60) |
| Casual | 2.10 (1.91 to 2.31) | 1.76 (1.60 to 1.95) |
| Recent self-reported HIV test result | ||
| Indeterminate result/or did not receive result (reference) | 1.00 | 1.00 |
| Negative result | 0.78 (0.69 to 0.88) | 0.86 (0.76 to 0.99) |
| Positive result | 0.49 (0.39 to 0.62) | 0.63 (0.50 to 0.80) |
*The multivariable model assessed the relationships of place-based factors significant at p<0.20 in univariate models to homelessness, controlling for individual-level confounders.