Figure 1.

Annual prevalence of patients with clinically amyopathic dermatomyositis or anti-melanoma differentiation-associated gene 5 antibodies. The regression equation is shown, in which the year of disease onset is defined as 1994 = 1, 1995 = 2,..., 2010 = 17 on the x axis and the presence or absence of clinically amyopathic dermatomyositis (CADM) or anti-melanoma differentiation-associated gene 5 (anti-MDA-5) antibodies is defined as 1 and 0, respectively, on the y axis (P for linear trend).