Table 2.

Marginal Structural Cox Model Estimates for the Effect of Treatment Regimen on Postindex Virologic Failure (n = 532)

Exposure	Person-Years	Number of Virologic Failure	Crude HR (95% CI)	IPTW×IPCW-Weighted Marginal Structural Model HR (95% CI)
Exposure to PI/r with 2 NRTIs	723.56	23	1 (reference)	1 (reference)
Exposure to dolutegravir with 2 NRTIs	291.54	5	0.54 (0.23–1.24)	0.57 (0.21–1.52)

Abbreviations: CI, confidence interval; HR, hazard ratio; IPCW, inverse probability of censoring weights; IPTW, inverse probability of treatment weights; NRTIs, nucleoside reverse-transcriptase inhibitors; PI/r, protease inhibitor/ritonavir.