TABLE 4.
Univariate and multivariable Cox proportional hazards ratios and 95% confidence intervals (CI) among people diagnosed with acquired immunodeficiency syndrome (AIDS) in urban areas, 1993–2007: hazards ratio and 95% confidence interval
| Characteristic | Model 1 Unadjusted hazards ratio (95% CI)a n = 71,599 |
Model 2 Adjusted hazards ratioa (95% CI) n = 71,143 |
Model 3 Adjusted hazards ratioa (95% CI) n = 71,226 |
|---|---|---|---|
| Individual-level characteristics | |||
| Race/ethnicity | |||
| Non-Hispanic black | 1.27 (1.24–1.30) | 1.19 (1.13–1.25) | 1.19 (1.14–1.25) |
| Hispanic | 0.97 (0.93–1.00) | 1.07 (1.01–1.13) | 1.07 (1.01–1.12) |
| Other | 1.25 (1.16–1.35) | 1.26 (1.15–1.37) | 1.26 (1.15–1.38) |
| Non-Hispanic white | Referent | Referent | Referent |
| Age at diagnosis (per year) | 1.02 (1.02–1.02) | 1.03 (1.03–1.03) | 1.03 (1.03–1.03) |
| Sex | |||
| Female | 0.98 (0.96–1.00) | 1.03 (1.00–1.06) | |
| Male | Referent | Referent | |
| Year of diagnosis | |||
| 1993–1995 | 2.33 (2.22–2.46) | 2.43 (2.30–2.56) | 2.43 (2.30–2.57) |
| 1996–1998 | 1.34 (1.27–1.42) | 1.32 (1.26–1.39) | 1.33 (1.26–1.40) |
| 1999–2001 | 1.15 (1.08–1.21) | 1.09 (1.03–1.16) | 1.09 (1.04–1.16) |
| 2002–2004 | 1.05 (0.99–1.11) | 1.01 (0.95–1.07) | 1.01 (0.95–1.07) |
| 2005–2007 | Referent | Referent | Referent |
| Country of birth | |||
| United States | 1.21 (1.17–1.24) | 1.34 (1.29–1.40) | 1.35 (1.29–1.41) |
| Not United States | Referent | Referent | Referent |
| Mode of transmission | |||
| Men who have sex with men | 0.94 (0.91–0.96) | 1.01 (0.98–1.05) | 0.99 (0.96–1.03) |
| Injection drug useb | 1.30 (1.26–1.34) | 1.19 (1.14–1.24) | 1.17 (1.12–1.23) |
| Heterosexual | Referent | Referent | Referent |
| Other/unknown | 1.83 (1.77–1.90) | 1.74 (1.67–1.82) | 1.73 (1.66–1.80) |
| Lowest CD4 count/µL CD4% categoryc | |||
| < 20 or < 3% | 2.60 (2.49–2.72) | 2.58 (2.47–2.71) | 2.58 (2.46–2.70) |
| 20–53 or 3%–5% | 2.09 (2.00–2.18) | 2.09 (1.99–2.19) | 2.08 (1.99–2.18) |
| 54–110 or 6%–8% | 1.70 (1.63–1.78) | 1.66 (1.59–1.74) | 1.66 (1.59–1.74) |
| 111–161 or 9%–11% | 1.26 (1.21–1.32) | 1.24 (1.18–1.31) | 1.24 (1.18–1.31) |
| 162–199 or 12%–13% | Referent | Referent | Referent |
| Met case definition with opportunistic infection only | 2.27 (2.16–2.37) | 1.96 (1.85–2.08) | 1.96 (1.85–2.08) |
| ZCTA-level characteristics | |||
| Poverty: Index of poverty in ZIP code tabulation areac, d | |||
| Less poverty (< −0.138) | Referent | Referent | Referent |
| More poverty (≥ −0.138) | 1.20 (1.09–1.31) | 1.10 (1.06–1.16) | 1.11 (1.06–1.17) |
| Townsend: Townsend-like index of deprivation in ZIP code tabulation area (ZCTA)d | |||
| Less deprivation (< −0.159) | Referent | Referent | |
| More deprivation (≥ −0.159) | 1.09 (0.96–1.24) | 0.98 (0.92–1.04) | |
| Affluence: Index of lack of affluence in ZCTAc,d | |||
| More affluence (< 0.262) | Referent | Referent | |
| Less affluence (≥0.262) | 1.12 (1.05–1.21) | 1.03 (0.98–1.07) | |
| County-level characteristics | |||
| Average total number of MD/OD per 100 square miles | |||
| < 19.744 | 1.06 (0.91–1.25) | 1.22 (1.05–1.42) | 1.17 (1.02–1.33) |
| ≥ 19.744 | Referent | Referent | Referent |
| Average number of hospitals per 100 square miles | |||
| < 0.2062 | 0.87 (0.77–0.98) | 0.94 (0.87–1.01) | |
| ≥ 0.2062 | Referent | Referent | |
| Ten year average of age-adjusted homicide rates per 100,000 from 1996–2005 | |||
| < 5.6 | Referent | Referent | |
| ≥ 5.6 | 1.07 (1.00–1.13) | 1.03 (0.98–1.08) | |
| Percent of population always or usually receiving needed social and emotional support | |||
| < 77.6% | 1.05 (0.99–1.12) | 1.04 (0.99–1.08) | 1.05 (1.01–1.10) |
| ≥ 77.6% | Referent | Referent | Referent |
Model 1: Only single factors were considered one at a time in the model. Hazards ratios are not adjusted for any other factors. Model 2: Hazards ratios are adjusted for all characteristics in the table. Model 3: Hazards ratios are adjusted for only the statistically significant characteristics in the table. Manual backward selection was performed (based on p-value ≥ 0.05).
Includes men who have sex with men who also reported injection drug use.
For CD4 count/percent category there were 365 missing values (0.50% of total), for affluence index there were 83 missing values (0.12% of total), and for poverty index there were 8 missing values (0.01% of total).
Poverty index includes 4 socioeconomic status (SES) variables, namely, percentage of households in ZCTA below poverty line, percentage of households in ZCTA with annual income less than $15,000, percentage of individuals in ZCTA with less than 12th grade, and income disparity in ZCTA (defined as the ratio of % of low income to % of high income).
Townsend-like index includes 4 SES variables, namely, percentage of households in ZCTA with no access to a car, percentage of households in ZCTA with more 1 person per room, percentage of households in ZCTA living in rented house, and percentage of individuals 16 years old or more in ZCTA unemployed.
Affluence index includes 5 SES variables, namely, median income household in 1999, percentage of households in ZCTA with annual income of at least $150,000, percentage of persons in ZCTA aged 25 years and older with a graduate or professional degree, percentage of persons in ZCTA employed in the predominantly high working class occupations, and percentage of owner-occupied homes in ZCTA area worth at least $300,000.