Table 2.
Crude DiD outcomes and odds ratio by logistic regression
| Test cohorta | Control cohortb | Between-group odds ratio/difference | ||||
|---|---|---|---|---|---|---|
| (n = 363) | (n = 6399) | Mean | 95 % CI | p Valuec | –2 Log Ld | |
| Including −1Q before index date | ||||||
| Patients with MS relapse, n (%) | ||||||
| Overall in pre-period | 109 (30.0) | 898 (14.0) | 2.63 | 2.08, 3.33 | 0.0000 | 5634 |
| Overall in post-period | 50 (13.8) | 739 (11.5) | 1.22 | 0.90, 1.67 | 0.1994 | 4870 |
| Excluding −1Q before index date | ||||||
| Patients with MS relapse, n (%) | ||||||
| Overall in pre-period | 76 (20.9) | 736 (11.5) | 2.04 | 1.56, 2.65 | 0.0000 | 4939 |
| Overall in post-period | 50 (13.8) | 739 (11.5) | 1.22 | 0.90, 1.67 | 0.1994 | 4870 |
CI confidence interval, DiD difference-in-differences, FTY fingolimod, GA glatiramer acetate, MS multiple sclerosis; Q quarter, OR odds ratio, SD standard deviation
aThe Test Cohort included patients who switched from GA to FTY
bControl Cohort included patients who remained on GA
cChi-square test (Fisher’s exact test is employed when ≥20 % of the cells have an expected value <5) for categorical/dummy variables and 2-sided 2-sample t test with unequal variance for continuous variables
dThere were two subpopulations and two model parameters in each logistic regression model and residual degrees of freedom is zero. Therefore, the Pearson and deviance goodness-of-fit tests cannot be obtained