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. Author manuscript; available in PMC: 2018 Mar 21.
Published before final editing as: Stat Methods Med Res. 2016 Sep 21;27(6):1709–1722. doi: 10.1177/0962280216668554

Table 5.

Comparison of the analytical approaches to adjust for time-dependent covariate from simulation-II (one baseline covariate, one time-dependent covariate and time-dependent treatment exposure) of 1, 000 datasets, each containing 2, 500 subjects followed for up to 10 time-intervals.

Approach Bias SD se Coverage Probability
TD-Cox§ 0.000 0.164 0.162 0.952
Sequential Cox#, 0.271 0.189 0.184 0.688
Modified Sequential Cox*, @ −0.022 0.231 0.234 0.961
MSCM±, −0.001 0.163 0.162 0.952

TD-Cox, Cox model with time-dependent exposure; MSCM, Marginal structural Cox model.

§

The baseline covariate L0 and time-dependent covariate Lm are included.

#

Adjusts for L0 and m.

In the stabilized IPCW model, the numerator model adjusts for Am and L0, while the denominator model adjusts for Am, L0 and m via Aalen’s additive model.

*

Adjusts for baseline covariates L0, lagged values of Am, the time-dependent confounder L⃗m, and lagged values of L⃗m.

@

For the stabilized IPCWs, the numerator model adjusts for Am and baseline variable L0, while the denominator model adjusts for L0, Am, L⃗m and lagged values of L⃗m via Aalen’s additive regression.

±

Adjusts for only L0.

For the stabilized IPTWs, the numerator model adjusts for the time index, L0 and lagged values of Am, while the denominator model additionally adjusts for current and lagged values of Lm to predict future treatment status via pooled logistic models.