Table 2.

Frequency and size of new enhancing lesions (months 1 to 6) 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.
† Thirty-seven patients (27 placebo/10 IFNβ-1b) developed at least 1 large and at least 1 small enhancing lesion.
IFNβ-1b = interferon β-1b.
Proportion of patients developing
    Any enhancing lesions38 (70.4%)28 (47.5%)−22.9%0.0131
    Only small (<5 mm) enhancing lesions8 (14.8%)13 (22.0%)7.2%
    At least one large (≥5 mm) enhancing lesion30 (55.6%)15 (25.4%)−30.2%0.0016
Cumulative number of new enhancing lesions per patient
    Any lesions
        Mean (SD)9.3 (13.6)3.0 (9.1)−6.30.0008
        Median3.00−3.0
    Small lesions (<5 mm)
        Mean (SD)6.9 (10.9)1.9 (4.3)−5.00.0011
        Median1.50−1.5
    Large lesions (≥5 mm)
        Mean (SD)2.4 (3.3)1.2 (5.4)−1.20.0010
        Median1.00−1.0
Cumulative number of new enhancing lesions per group
    Any lesions500179−321
    Small lesions (<5 mm)372110−262
    Large lesions (≥5 mm)12869−59