TABLE 3.
Multilevel Ordinal Regression of the Likelihood of Injecting With a Sterile Syringe on Spatial Access to SEPs and to Pharmacies Selling Syringes OTC in New York City Health Districts: 1995–2006
| Predictor Variable | Model A: Growth Curve, OR (95% CI) | Model B: SEP Access Within 1.00 Mile, OR (95% CI) | Model C: SEP Access Within 0.50 Mile, OR (95% CI) | Model D: SEP Access Within 0.25 Mile, OR (95% CI) | Model E: OTC Pharmacy and SEP Access Within 0.50 Mile,a OR (95% CI) |
| Individual-level covariates | |||||
| Intercept 1b | 0.16 (0.09, 0.28) | 0.11 (0.05, 0.26) | 0.11 (0.05, 0.24) | 0.12 (0.06, 0.27) | 0.10 (0.05, 0.21) |
| Intercept 2c | 0.38 (0.23, 0.65) | 0.27 (0.13, 0.59) | 0.25 (0.11, 0.55) | 0.29 (0.13, 0.63) | 0.23 (0.22, 0.50) |
| Age, y | |||||
| 18–30 | 0.89 (0.74, 1.07) | 0.89 (0.73, 1.06) | 0.88 (0.74, 1.06) | 0.88 (0.74, 1.06) | 0.88 (0.73, 1.05) |
| > 30 (Ref) | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| Gender | |||||
| Men (Ref) | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| Women | 1.26 (1.07, 1.49) | 1.26 (1.07, 1.48) | 1.26 (1.07, 1.49) | 1.26 (1.07, 1.49) | 1.26 (1.07, 1.48) |
| Race/ethnicity | |||||
| Hispanic/Latino (any race; Ref) | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| Non-Hispanic Black | 1.05 (0.88, 1.25) | 1.06 (0.89, 1.25) | 1.06 (0.90, 1.26) | 1.06 (0.90, 1.26) | 1.05 (0.88, 1.24) |
| Non-Hispanic White/Other | 0.80 (0.68, 0.94) | 0.83 (0.71, 0.98) | 0.83 (0.70, 0.97) | 0.82 (0.67, 0.96) | 0.82 (0.70, 0.96) |
| Homeless | 0.77 (0.67, 0.88) | 0.76 (0.66, 0.87) | 0.76 (0.66, 0.87) | 0.76 (0.66, 0.87) | 0.76 (0.66, 0.87) |
| Lesbian/gay/bisexual | 0.89 (0.72, 1.11) | 0.88 (0.71, 1.10) | 0.88 (0.71, 1.09) | 0.87 (0.70, 1.09) | 0.87 (0.70, 1.08) |
| HIV-positive (self-report) | 1.00 (0.81, 1.22) | 1.00 (0.81, 1.21) | 0.99 (0.81, 1.21) | 0.98 (0.80, 1.20) | 0.98 (0.80, 1.20) |
| Injection frequency in past 6 mo, times/d | |||||
| < 1 (Ref) | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| 1–3 | 0.53 (0.45, 0.63) | 0.53 (0.45, 0.63) | 0.53 (0.45, 0.63) | 0.53 (0.44, 0.63) | 0.53 (0.44, 0.63) |
| ≥ 4 | 0.38 (0.32, 0.45) | 0.38 (0.32, 0.45) | 0.38 (0.32, 0.45) | 0.37 (0.31, 0.44) | 0.37 (0.32, 0.45) |
| Deviation from mean years of injecting for district and year | 1.00 (0.99, 1.01) | 1.00 (1.00, 1.01) | 1.00 (1.00, 1.01) | 1.00 (1.00, 1.01) | 1.00 (1.00, 1.01) |
| District-level predictors | |||||
| Time-varying predictors | |||||
| Years since study began | 0.80 (0.74, 0.86) | 0.76 (0.70, 0.83) | 0.77 (0.71, 0.84) | 0.78 (0.72, 0.85) | 0.87 (0.83, 0.92) |
| Years since study began, squared | 1.02 (1.01, 1.03) | 1.03 (1.02, 1.03) | 1.02 (1.02, 1.03) | 1.02 (1.02, 1.03) | … |
| Years since OTC pharmacy sales permitted | … | … | … | … | 0.20 (0.11, 0.38) |
| Years since OTC pharmacy sales permitted × years since study began | … | … | … | … | 1.16 (1.10, 1.21) |
| OTC pharmacy sales permitted | … | … | … | … | 3.61 (2.17, 6.02) |
| Mean years since first injection for that district and year | 1.01 (0.99, 1.03) | 1.01 (0.99, 1.03) | 1.02 (1.00, 1.03) | 1.02 (1.00, 1.03) | 1.02 (1.00, 1.03) |
| Decline in % of residents who were non-Hispanic White in that year and districtd | … | 1.25 (0.99, 1.60) | 1.27 (1.00, 1.61) | 1.22 (0.96, 1.55) | 1.22 (0.97, 1.54) |
| Natural log of annual change in spatial access to an SEP since 1995 | … | 1.23 (1.01, 1.52) | 1.30 (1.03, 1.64) | 1.34 (1.01, 1.84) | 1.25 (1.00, 1.55) |
| Natural log of spatial access to OTC pharmacy | … | … | … | … | 1.15 (1.03, 1.27) |
| Time-invariant predictors | |||||
| Natural log of spatial access to SEPs in 1995 | … | 1.26 (1.03, 1.54) | 1.46 (1.14, 1.86) | 1.69 (1.18, 2.41) | 1.43 (1.13, 1.80) |
| Natural log of % of residents who were non-Hispanic White in 1995 | … | 0.95 (0.87, 1.04) | 0.95 (0.87, 1.03) | 0.93 (0.85, 1.01) | 0.95 (0.87, 1.03) |
| Cross-level interaction | |||||
| Natural log of spatial access to SEPs in 1995 × natural log of annual change in spatial access to SEPs since 1995 | … | 0.95 (0.88, 1.02) | 0.89 (0.81, 0.98) | 0.79 (0.65, 0.96) | 0.90 (0.82, 0.98) |
Note. CI = confidence interval; OR = odds ratio; OTC = over the counter; SEP = syringe exchange program. Ellipses indicate the predictor was not applicable. Injectors, n = 4003; health districts, n = 42.
a
Spatial access to OTC pharmacies was assessed for 2003 onward; previous values were set to zero.
b
Intercept when the outcome was injecting with a sterile syringe during at least 75% of injection events in the past 6 months.
c
Intercept when the outcome was injecting with a sterile syringe during at least 26% of injection events in the past 6 months.
d
Reference was stasis or no decline.