691 patients were evaluated for analysis, 618 were included, 73 were excluded because of a change in stavudine dose or because stavudine dose was not recorded at a visit. Sex, age, and HIV RNA<400 c/mL at six months were similar between included and excluded patients. Of the included cART naïve subjects (all weighed >60kg at baseline and initiated cART between January 2006 and January 2008 at 51 community ART clinic sites), 110 received 30mg and 508 received 40mg stavudine. The two stavudine dose groups were different with respect to WHO stage, proportion receiving efavirenz, weight, and median log10 HIV RNA and CD4 count at cART initiation (). 9 (8.1%) in the 30mg group and 46 (9.1%) in the 40mg group had no HIV RNA measurement during the observation period and were counted as treatment failures.
Baseline characteristics and univariate and multivariate associations between stavudine dose and HIV RNA <400 c/mL at 6 months.
We observed similar virologic suppression using <400 c/mL and <50 c/mL at 6 months by stavudine group: suppression to <400 c/mL for 30mg was 87/110 (79%, 95% confidence interval (CI): 71-87%) and for 40mg was 413/508 (81%, 95% CI: 78-85%) (p=0.6); <50 c/mL for 30mg was 66/110, (60%, 95% CI: 51-69%) and for 40mg was 297/508, (58%, 95% CI: 54-63%) (p=0.8). Completing sensitivity analysis excluding subjects without follow-up HIV RNA testing, we found 86% (95% CI: 0.79-0.93) and 89% (95% CI: 0.86-0.92) were suppressed with stavudine 30mg or 40mg groups, respectively (p=0.3). Using logistic regression we found no association between HIV RNA suppression and sex, weight, or WHO stage at cART initiation (). On univariate analysis, log10 HIV RNA at cART initiation, NNRTI agent, and weight all had p-values<0.1 for odds of achieving an HIV RNA <400 c/mL. On multivariate analysis adjusting for NNRTI agent, weight, and HIV RNA at cART initiation, stavudine dose remained unassociated with suppression (). CD4 change from cART initiation to 6 months on cART increased with a median of 126 cells/mm3 (IQR 87-206) for the 30mg group and 110 cells/mm3 (IQR 50-170) for the 40mg group (p=0.02).