Fig. 1.

The effect of follow-up time on four different effect estimates comparing all-cause mortality by IDU. Panel a) displays the standardized^a difference (with 95% confidence interval) in restricted mean time to all-cause mortality by history of injection drug use over follow-up time. Panel b) displays the standardized^a all-cause hazard ratio (HR) over follow-up time. Panel c) displays the standardized^a all-cause mortality risk ratio (RR) over follow-up time. Panel d) displays the standardized^a all-cause mortality risk difference (RD) over follow-up time. ^a Curves are standardized to the distribution of sex, race, AIDS diagnosis, prior ART mono- or dual-therapy, age, CD4 cell count, log₁₀ HIV viral load, Hepatitis C, history of smoking, and hazardous alcohol use in the total sample at clinic enrollment using inverse probability of exposure weights. ^b Dashed grey lines represent the null hypothesis (i.e. difference in RMST = 0, HR = 1, RR = 1, and RD = 0) in each panel. ^c The dot-dash black line on panel b is the HR estimated from the Cox Proportional Hazards Model. ^d The solid black line on panels b, c, and d is the lowess smoother to show the overall trend of the estimands. ^e The RR and RD is defined as $\left(1-S_{\mathit{\text{PWID}}}^w\left(t\right)\right)/\left(1-S_{\mathit{\text{non}}-\mathit{\text{PWID}}}^w\left(t\right)\right)$ and $\left(1-S_{\mathit{\text{PWID}}}^w\left(t\right)\right)-\left(1-S_{\mathit{\text{non}}-\mathit{\text{PWID}}}^w\left(t\right)\right)$, respectively, where $S_{\bullet }^w\left(t\right)$ is the weighted survival curve