Table 3.
Negative binomial DID model for the number of MS relapses
| Parameter | Estimate | SE | 95% CI | p value |
|---|---|---|---|---|
| Test Cohorta vs Control Cohortb (including –1Q before index date) | ||||
| Intercept | −1.78 | 0.02 | −1.82, −1.73 | <0.0001 |
| Cohort: GA → FTY (reference = Control Cohort) | 0.71 | 0.08 | 0.55, 0.87 | <0.0001 |
| Time: post-period (reference = pre-index period) | −0.19 | 0.04 | −0.26, −0.12 | <0.0001 |
| Cohort × time | −0.44 | 0.13 | −0.69, −0.18 | 0.0007 |
| Test Cohorta vs. Control Cohortb (excluding –1Q before index date) | ||||
| Intercept | −2.04 | 0.03 | −2.09, −1.99 | <0.0001 |
| Test Cohort (reference = control cohort) | 0.56 | 0.09 | 0.39, 0.74 | <0.0001 |
| Time: post-period (reference = pre-index period) | 0.08 | 0.04 | 0.01, 0.15 | 0.0303 |
| Cohort × time | −0.29 | 0.13 | −0.55, −0.03 | 0.0276 |
CI confidence interval, DiD difference-in-differences, FTY fingolimod, GA glatiramer acetate, MS multiple sclerosis; Q quarter, S standard error
aThe Test Cohort included patients who switched from GA to FTY
bControl Cohort included patients who remained on GA