Figure 4.

Inverse probability of treatment and censoring weight-adjusted Kaplan-Meier-type survival curves for the association between β-interferon treatment and time to a sustained Expanded Disability Status Scale score of 6 among multiple sclerosis patients from British Columbia, Canada, 1995–2008. A) Unweighted; B) adjusted by w⁽ⁿ⁾ (untruncated); C) adjusted by 5% truncated w⁽ⁿ⁾; D) adjusted by 10% truncated w⁽ⁿ⁾; E) adjusted by 25% truncated w⁽ⁿ⁾; F) adjusted by 50% truncated w⁽ⁿ⁾. The truncated weights are derived from the normalized unstabilized weights (w⁽ⁿ⁾) so that the survival probabilities and hazard ratios are marginal estimates with a causal interpretation.