Table 1.

Characteristics of patients reaching the ABN criteria in the BCMS database after 1980 (the ‘natural history’ untreated comparator cohort) and the RSS cohort

Baseline (eligible for DMT)	BCMS (1980–1995*)	RSS full cohort RSS analysis cohort†
N	898	5610 4138
Females: n (%)	666 (74.2)	4162 (74.2) 3125 (75.5)
Age at baseline, years: mean (SD; range)	37.2 (9.32; 18–69)	39.4 (9.05; 15–73) 38.4 (8.58; 18–73)
Age at onset of MS, years: mean (SD; range)	29.3 (8.65; 3–61)	30.5 (8.52; 5–68) 30.5 (8.38; 5–68)
Disease duration at baseline, years: mean (SD; range)	7.9 (6.89; 0.2–38.9)	8.8 (7.47; 0–46) 7.7 (6.62; 0–41)
SPMS documented at baseline‡ n (%)	141 (15.7)	772 (13.8) –
Relapses in the past 2 years prior to eligibility: median (quartiles)	2 (2–3)	3 (2–3) 3 (2–3)
First eligible EDSS: median (quartiles; range)	2 (1, 3.5; 0–6.5)	3.5 (2.0, 5.0; 0–8.0) 3.0 (2.0, 4.0; 0–6.5)

‘Eligibility’ refers to the first time a patient fulfilled the ABN criteria.

*Data were truncated to 1995 in the final models to minimise DMT exposure in the cohort.

†‘Analysis cohort’ is the subset of patients eligible for the analysis (eg, treated patients, at least one postbaseline EDSS available, etc).

‡All were still DMT eligible.

ABN, Association of British Neurologists; BCMS, British Columbia Multiple Sclerosis database; DMT, disease modifying treatment; EDSS, Expanded Disability Status Score; RSS, Risk-sharing Scheme.