Table 3.
Final multivariable Cox model of the associations of insulin-like growth factor (IGF)–I and IGF-binding protein (IGFBP)–3 levels with the risk of AIDS.
| Variable | HR (95% CI)a | Ptrendb |
|---|---|---|
| CD4+ T cell count | <.001 | |
| <200 cells/mm3 | 2.79 (1.64–4.76)*** | |
| 200–350 cells/mm3 | 1.11 (0.61–2.01) | |
| >350–500 cells/mm3 | 0.81 (0.42–1.56) | |
| >500 cells/mm3 | Reference | |
| HCV seropositive | 2.18 (1.39–3.42)*** | |
| Age group | ||
| 26–30 years | 1.62 (0.53–5.01) | |
| 31–35 years | 1.59 (0.54–4.63) | |
| 36–45 years | 1.32 (0.45–3.90) | |
| >45 years | 0.77 (0.22–2.78) | |
| <26 years | Reference | |
| IGF-I level | ||
| Fourth quartile | 0.64 (0.35–1.18) | |
| Third quartile | 0.80 (0.42–1.51) | |
| Second quartile | 0.70 (0.36–1.37) | |
| First quartile | Reference | |
| IGFBP-3 level | .02 | |
| Fourth quartile | 2.65 (1.30–5.42)*** | |
| Third quartile | 1.77 (0.89–3.54) | |
| Second quartile | 1.62 (0.86–3.07) | |
| First quartile | Reference | |
NOTE. Although IGF-I level and age were not statistically significantly associated with incident AIDS, they were retained in the final model because of their perceived biological relevance to the association between IGFBP-3 level and incident clinical AIDS as well as this being the a priori statistical model determined before data analysis. CI, confidence interval; HR, hazard ratio.
a
*P < .05; **P < .01; ***P < .001.
b
Ptrend is reported only for ordinal data and only if statistically significant (i.e., <.05).