Table 2.
Bivariate and multivariate relative all-cause hospitalization rates
| Simple incidence rate ratio (95% CI) | P | Multivariate incidence rate ratio (95% CI) | P | |
|---|---|---|---|---|
| Virological responders over time | ||||
| Prior 6 months | 1.05 (0.80, 1.38) | 0.73 | 1.11 (0.84, 1.47) | 0.44 |
| Days 1–45 after HAART initiation | 1.00 | Ref | 1.00 | Ref |
| Days 46–90 | 0.71 (0.51, 0.98) | 0.04 | 0.74 (0.53, 1.03) | 0.08 |
| Days 91–180 | 0.56 (0.40, 0.78) | 0.001 | 0.59 (0.42, 0.82)† | 0.002 |
| Days 181–365 | 0.64 (0.47, 0.88) | 0.006 | 0.69 (0.49, 0.95)† | 0.02 |
| Nonresponders over time | ||||
| Prior 6 months | 1.14 (0.78, 1.69) | 0.49 | 1.19 (0.78, 1.81) | 0.41 |
| Days 1–45 after HAART initiation | 1.00 | Ref | 1.00 | Ref |
| Days 46–90 | 1.01 (0.60, 1.68) | 0.97 | 1.14 (0.68, 1.90) | 0.62 |
| Days 91–180 | 1.26 (0.79, 2.01) | 0.34 | 1.43 (0.89, 2.31) | 0.14 |
| Days 181–365 | 0.99 (0.63, 1.55) | 0.97 | 1.11 (0.70, 1.76) | 0.65 |
| Age | ||||
| 18–29 years | 1.00 | Ref | ||
| 30–39 years | 1.00 (0.67, 1.49) | 0.99 | ||
| 40–49 years | 1.15 (0.76, 1.74) | 0.52 | ||
| ≥50 years | 1.21 (0.77, 1.92) | 0.41 | ||
| Gender | ||||
| Female | 1.39 (1.13, 1.72) | 0.002 | 1.41 (1.14, 1.74) | 0.001 |
| Male | 1.00 | Ref | 1.00 | Ref |
| Race | ||||
| African American | 1.93 (1.42, 2.63) | <0.001 | 1.46 (1.06, 1.99) | 0.02 |
| Non-African American | 1.00 | Ref | 1.00 | Ref |
| HIV risk factor | ||||
| IDU | 1.55 (1.26, 1.92) | <0.001 | 1.43 (1.17, 1.76) | 0.001 |
| Non-IDU | 1.00 | Ref | 1.00 | Ref |
| CD4 count at HAART initiation | ||||
| <50 cells/µL | 2.63 (2.06, 3.36) | <0.001 | 2.27 (1.65, 3.13) | <0.001 |
| 50–199 cells/µL | 1.46 (1.11, 1.92) | 0.007 | 1.35 (1.01, 1.81) | 0.04 |
| ≥200 cells/µL | 1.00 | Ref | 1.00 | Ref |
| HIV-1 RNA at HAART initiation | ||||
| <4 log10 copies/mL | 1.00 | Ref | 1.00 | Ref |
| 4–5 log10 copies/mL | 1.08 (0.78, 1.50) | 0.64 | 0.94 (0.68, 1.29) | 0.69 |
| ≥5 log10 copies/mL | 1.82 (1.33, 2.47) | <0.001 | 1.26 (0.89, 1.79) | 0.20 |
| HAART type | ||||
| NNRTI (plus ≥2 NRTIs) | 1.00 | Ref | ||
| PI (plus ≥2 NRTIs) | 1.00 (0.80, 1.25) | 0.99 | ||
| Both PI and NNRTI (plus ≥1 NRTI) | 1.07 (0.77, 1.49) | 0.68 | ||
| Calendar era of HAART initiation | ||||
| 1997–1998 | 1.00 | Ref | ||
| 1999–2002 | 1.11 (0.88, 1.40) | 0.37 | ||
| 2003–2006 | 1.11 (0.82, 1.49) | 0.49 | ||
| PCP prophylaxis at HAART initiation* | ||||
| Use | 2.45 (1.90, 3.15) | <0.001 | ||
| Nonuse | 1.00 | Ref | ||
| MAC prophylaxis at HAART initiation* | ||||
| Use | 2.48 (2.02, 3.05) | <0.001 | ||
| Nonuse | 1.00 | Ref | ||
| CD4 count increase at 6 months | ||||
| <101 cells/µL | 1.00 | Ref | 1.00 | Ref |
| ≥101 cells/µL | 0.69 (0.55, 0.86) | 0.001 | 0.83 (0.67, 1.03) | 0.09 |
Significant values are shown in bold.
In a multivariate model (not shown) which included CD4 cell count and use of PCP and MAC prophylaxis variables, relative hospitalization rates over time after HAART initiation were not significantly affected. As lower CD4 cell counts were highly associated with use of prophylaxis, and because CD4 cell count was felt to cause the use of prophylaxis, PCP prophylaxis and MAC prophylaxis were not included in the final multivariate model reported above.
Multivariate P<0.05 for responders vs. nonresponders within the 91–180 and 181–365 day time periods.
CI, confidence interval; HAART, highly active antiretroviral therapy; IDU, injecting drug use; MSM, men who have sex with men; PI, protease inhibitor; NNRTI, nonnucleoside reverse transcriptase inhibitor; NRTI, nucleoside reverse transcriptase inhibitor; PCP, Pneumocystis pneumonia; MAC, Mycobacterium avium complex.