Table 2.

Fit of the Marginal Structural Cox Model With the Normalized Stabilized IPTC Weights (sw⁽ⁿ⁾) for Time to a Sustained EDSS Score of 6 (Sustained EDSS 6) in Estimating the Causal Association Between β-Interferon Treatment and the Hazard of Reaching Sustained EDSS 6 Among Multiple Sclerosis Patients From British Columbia, Canada, 1995–2008

Covariate	Estimated Log HRa	HRb	95% Bootstrap CIc
β-Interferon use	0.31	1.36	0.95, 1.94
EDSS score	0.54	1.72	1.54, 1.92
Disease duration, decades	−0.19	0.83	0.66, 1.05
Age, decades	0.28	1.32	1.08, 1.62
Sexd	−0.22	0.80	0.55, 1.17

Abbreviations: CI, confidence interval; EDSS, Expanded Disability Status Scale; HR, hazard ratio; IPTC, inverse probability of treatment and censoring.

^a Estimated log HR from a marginal structural Cox model. The model also adjusted for the baseline covariates EDSS score, age, disease duration, and sex.

^b Instantaneous risk of reaching a confirmed sustained EDSS score of 6.

^c Based on 500 nonparametric bootstrap samples.

^d Referent: male.