Table 3. Marginal structural model estimates vs. Traditional model estimates of the effect of source of payment for HIV medication on adherence.

Method	Difference in mean adherence (95% CI)
Marginal Structural Model	3.82 (0.97–6.66)
Generalized Estimating Equations
Crude	6.26 (2.66–9.85)
Adjusted*	3.10 (0.95–5.24)
Ordinary Least Squares
Crude	5.06 (1.09–9.04)
Adjusted*	3.33 (−0.57–7.24)

^*adjusted for income, duration on ART, prior adherence, prior CD4+ T cell count, prior HIV RNA.