TABLE 3.
Univariate and multivariable Cox proportional hazards ratios for Floridians diagnosed with acquired immunodeficiency syndrome (AIDS) in rural areas, 1993–2007: hazards ratio* and 95% confidence interval
| Characteristic | Model 1 Unadjusted hazards ratioa (95% CI) n = 1,991† |
Model 2 Adjusted hazards ratioa (95% CI) n = 1,978 |
Model 3 Adjusted hazards ratioa (95% CI) n = 1,982 |
|---|---|---|---|
| Individual-level characteristics | |||
| Race/ethnicity | |||
| Non-Hispanic black | 1.14 (0.99–1.32) | 1.12 (0.90–1.40) | |
| Hispanic | 0.94 (0.73–1.21) | 0.92 (0.67–1.26) | |
| Other | 1.17 (0.75–1.83) | 1.13 (0.80–1.61) | |
| Non-Hispanic white | Referent | Referent | |
| Age at diagnosis (per year) | 1.03 (1.02–1.04) | 1.03 (1.03–1.04) | 1.03 (1.03–1.04) |
| Sex | |||
| Female | 0.88 (0.76–1.02) | 1.07 (0.89–1.28) | |
| Male | Referent | Referent | |
| Year of diagnosis | |||
| 1993–1995 | 1.86 (1.43–2.42) | 1.95 (1.50–2.53) | 1.93 (1.50–2.48) |
| 1996–1998 | 1.08 (0.82–1.41) | 0.99 (0.74–1.33) | 0.99 (0.74–1.31) |
| 1999–2001 | 0.92 (0.70–1.22) | 0.84 (0.62–1.13) | 0.84 (0.63–1.13) |
| 2002–2004 | 0.90 (0.67–1.20) | 0.82 (0.60–1.12) | 0.82 (0.60–1.12) |
| 2005–2007 | Referent | Referent | Referent |
| Country of birth | |||
| United States | 1.04 (0.80–1.35) | 0.95 (0.72–1.25) | |
| Not United States | Referent | Referent | |
| Mode of transmission | |||
| Men who have sex with men | 1.08 (0.91–1.28) | 1.13 (0.91–1.40) | 1.07 (0.89–1.28) |
| Injection drug useb | 1.05 (0.87–1.25) | 1.14 (0.90–1.45) | 1.09 (0.87–1.36) |
| Heterosexual | Referent | Referent | Referent |
| Other/unknown | 1.83 (1.52–2.22) | 1.74 (1.43–2.10) | 1.70 (1.42–2.05) |
| Lowest CD4 count/µL CD4% categoryc | |||
| < 20 or < 3% | 3.68 (2.79–4.85) | 3.89 (3.01–5.04) | 3.92 (3.02–5.09) |
| 20–53 or 3%–5% | 2.71 (2.05–3.59) | 2.73 (2.09–3.55) | 2.66 (2.03–3.47) |
| 54–110 or 6%–8% | 2.10 (1.58–2.80) | 2.17 (1.60–2.94) | 2.14 (1.60–2.87) |
| 111–161 or 9%–11% | 1.68 (1.24–2.26) | 1.67 (1.28–2.17) | 1.66 (1.29–2.15) |
| 162–199 or 12%–13% | Referent | Referent | Referent |
| Met case definition with opportunistic infection only | 3.17 (2.36–4.27) | 2.84 (2.09–3.86) | 2.82 (2.10–3.80) |
| ZCTA-level characteristics | |||
| Poverty: Index of poverty in ZIP code tabulation aread | |||
| Less poverty (< −0.138) | Referent | Referent | |
| More poverty (≥ −0.138) | 1.17 (0.86–1.60) | 1.18 (0.76–1.82) | |
| Townsend: Townsend-like index of deprivation in ZIP code tabulation aread | |||
| Less deprivation (< −0.159) | Referent | Referent | |
| More deprivation (≥ −0.159) | 1.00 (0.80–1.25) | 0.95 (0.72–1.26) | |
| Affluence: Index of lack of affluence in ZIP code tabulation areac,d | |||
| More affluence (< 0.262) | Referent | Referent | |
| Less affluence (≥0.262) | 1.06 (0.80–1.40) | 0.95 (0.66–1.37) | |
| County-level characteristics | |||
| Average total number of MD/DO per 100 square miles | |||
| < 19.744 | 0.96 (0.77–1.19) | 0.91 (0.65–1.28) | |
| ≥ 19.744 | Referent | Referent | |
| Average number of hospitals per 100 square miles | |||
| < 0.2062 | 1.07 (0.86–1.34) | 1.02 (0.76–1.36) | |
| ≥ 0.2062 | Referent | Referent | |
| Ten-year average of age-adjusted homicide rates per 100,000 from 1996–2005 | |||
| < 5.6 | Referent | Referent | |
| ≥ 5.6 | 1.06 (0.85–1.31) | 1.03 (0.78–1.36) | |
| Percent of population always or usually receiving needed social and emotional support | |||
| < 77.6% | 0.95 (0.81–1.12) | 0.89 (0.75–1.07) | |
| ≥ 77.6% | 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 ≥ .05).
Includes men who have sex with men who also reported injection drug use.
For CD4 count/percent category there were 9 missing values (0.5% of total), and for affluence index there were 4 missing values (0.2% of total).
Poverty index includes 4 socioeconomic status (SES) variables, namely, percentage of households in ZIP code tabulation area (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 education, 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, percentage of owner-occupied homes in ZCTA worth at least $300,000.