Table 3.

Frequency and size of new hypointense T1 lesions developing at follow-up in patients with at least 1 scan during months 19 to 24

ParameterPlacebo, n = 54IFNβ-1b, n = 59Absolute differencep Value*
* Comparison of proportions: Mantzel–Haenszel test with stratification adjustment for center. Comparison of number of lesions: extended Mantzel–Haenszel test with stratification adjustment for center.
† Eleven patients (8 placebo/3 IFNβ-1b) developed at least 1 large and at least 1 small hypointense T1 lesion.
IFNβ-1b = interferon β-1b.
Proportion of patients developing
    Any hypointense T1 lesions26 (48.1%)12 (20.3%)−22.9%0.0008
    Only small (<5 mm) hypointense T1 lesions13 (24.1%)7 (11.9%)−12.2%
    At least one large (≥5 mm) hypointense T1 lesion13 (24.1%)5 (8.5%)−15.6%0.0191
Cumulative number of new hypointense T1 lesions per patient
    Any lesions, mean (SD)1.3 (2.1)0.4 (1.5)−0.90.0005
    Small lesions (<5 mm), mean (SD)0.9 (1.4)0.2 (0.5)−0.70.0013
    Large lesions (≥5 mm), mean (SD)0.4 (1.0)0.2 (1.1)−0.20.0217
Cumulative number of new hypointense T1 lesions per group
    Any lesions7024−46
    Small lesions (<5 mm)4612−34
    Large lesions (≥5 mm)2412−12