Fig. 4.

Comparison of disability (most recent EDSS) between biopsied cohort and OC multiple sclerosis prevalence cohort stratified by disease duration. The OC multiple sclerosis prevalence cohort is denoted by ‘OC’ and the current biopsy cohort is denoted by ‘Bx’. Boxes extend to cover the middle 50% of the data. Median EDSS scores are indicated by the horizontal lines within each box, mean scores by the diamonds. Whiskers extend to furthest observation within 1.5 IQRs, with outlying points indicated by individual circles. Although median EDSS at last follow-up was slightly higher in the biopsy cohort compared with the OC multiple sclerosis prevalence cohort in patients with disease duration between 0 and 5 years (3.0 versus 1.5; P = 0.01), and 5–10 years (3.0 versus 2.0; P = 0.04), the EDSS was significantly lower in the biopsy cohort for 10+ years (1.5 versus 3.5; P < 0.001). Note that EDSS at last follow-up was unknown in eight patients, therefore, the data reflects 132 rather than 140 biopsied patients in whom detailed clinical information was available for analysis.