Table 3.
Exploratory testing of select mediators of the relationship between black residential isolation and the log rate of new HIV cases: 95 large US metropolitan statistical areas, 2008–2015.
| Independent variablesa | Standardized coefficient for bivariate model (95% CI) | Standardized coefficient for multivariate model (95% CI) | % changef in standardized coefficient for the focal exposureg |
|---|---|---|---|
| Newly diagnosed HIV cases per 10,000 white heterosexual adultsb | |||
| Baseline (2008) | 0.41 (0.27, 0.56) | 0.34 (0.20, 0.48) | −34.75 |
| Change between 2008 and 2015 | 0.05 (−0.02, 0.12) | 0.05 (−0.02, 0.12) | * |
| Equitable male to female ratio, black adultsb | |||
| Lagged baseline (2007) | −0.23 (−0.57, 0.11) | −0.06 (−0.39, 0.28) | 5.08 |
| Change between 2007 and 2014 (interaction of the variable with time) | 0.04 (−0.01, 0.09) | 0.03 (−0.02, 0.08) | * |
| Percentage of non-Hispanic black adultsb (25 and up) without a high school diploma or equivalent | |||
| Lagged baseline (2007) | 0.25 (0.11, 0.40) | 0.25 (0.11, 0.39) | −51.35 |
| Change between 2007 and 2014 | 0.01 (−0.08, 0.11) | 0.00 (−0.10, 0.04) | * |
| Ratioc of black to white adultsb without a high school diploma or equivalent, adjusted for population size | |||
| Lagged baseline (2007) | 0.24 (0.12, 0.35) | 0.22 (0.12, 0.33) | −15.48 |
| Change between 2007 and 2014 | −0.01 (−0.08, 0.06) | −0.02 (−0.09, 0.05) | * |
| Percentage of black employed adultsb | |||
| Lagged baseline (2007) | 0.14 (0.005, 0.27) | 0.09 (−0.03, 0.22) | 3.96 |
| Change between 2007 and 2014 | 0.02 (−0.06, 0.09) | 0.02 (−0.06, 0.10) | * |
| Ratioc of white to black employed adultsb, adjusted by population sized | |||
| Lagged baseline (2007) | −0.03 (−0.18, 0.11) | – | – |
| Change between 2007 and 2014 | −0.02 (−0.09, 0.05) | – | – |
| Percentage of black residents with incomee below poverty level | |||
| Lagged baseline (2007) | −0.06 (−0.21, 0.08) | −0.04 (−0.17, 0.10) | 2.71 |
| Change between 2007 and 2014 | 0.06 (−0.01, 0.12) | 0.06 (−0.01, 0.12) | * |
| Ratioc of black to white residents with incomee below poverty level, adjusted by population size | |||
| Lagged baseline (2007) | 0.16 (0.02, 0.30) | 0.12 (−0.02, 0.26) | −22.58 |
| Change between 2007 and 2014 | 0.06 (−0.01, 0.12) | 0.06 (−0.01, 0.12) | * |
2008 to 2015 is the timeframe for the outcome. Except for newly diagnosed HIV cases per 10,000 white heterosexual adults, correlates were lagged 1 year and reflect 2007–2014
Note: Correlates were lagged 1 year because we did not expect a change in the correlates to have an instantaneous effect on the outcome
*Due to the low absolute value of isolation change coefficient in the model without mediators, the relative change in this parameter is artificially high, so we do not report these findings
CI, confidence interval
aEach independent variable was added to the model one at a time
bFor this study, adults are defined as persons aged 15–64. For those without a high school diploma or equivalent, the census reports these data for those ages 25–64 to allow time for non-diploma holders to obtain an equivalent. Yearly sex ratios by race were only available from census intercensal estimates which report the age range 18–64
cRatios adjusted for population size are ratios of percentages out of the relevant population
dThis variable was not tested as a mediator in the multivariate models due to weak bivariate associations with the outcome
eIncome refers to individual income
fCompared to the standardized coefficients of the focal exposure (baseline isolation and change) for the final model without mediators (see Table 2)
gThe focal exposure is black isolation in the metro area