Table 2.

Agreement Kappa index between the three set of criteria applied in the Brazilian cohort of patients with primary progressive multiple sclerosis.

Criteria	Kappa index for agreement	95% confidence interval	p
Thompson and McDonald 2001	0.78	0.52–1.0	0.001
Thompson and McDonald 2005	0.52	0.28–0.76	<0.001
McDonald 2001 and McDonald 2005	0.27	0.01–0.53	0.042
Thompson, McDonald 2001 and McDonald 2005	0.54	0.39–0.70	<0.001