Predictors of survival in a cohort of patients with polymyositis and dermatomyositis: effect of corticosteroids, methotrexate and azathioprine

Table 1 Demographics and baseline characteristics of patients with PM versus DM^a

Characteristics	PM (n= 77)	DM (n= 83)	Pvalue
Age at diagnosis (years)	49.7 ± 13.0	47.2 ± 13.9	0.236
Females, n (%)	60 (77.9)	56 (67.5)	0.139
Race, n (%)			0.042
White, non-Hispanic	61 (79.2)	52 (62.7)
Black	13 (16.9)	15 (18.1)
Hispanic	0 (0)	2 (2.4)
Asian	0 (0)	1 (1.2)
Other or unknown	3 (3.9)	13 (15.7)
Median [IQR] initial CK level (IU/L)^b	3,250 [846 to 11,698]	415 [71 to 3,000]	0.0005
Interstitial lung disease, n (%)	21 (27.3)	16 (19.3)	0.231
Cancer, n (%)
Ever	13 (16.9)	12 (14.5)	0.673
Proportion diagnosed within ± 3 years of IIM diagnosis	5 (38.5)	11 (91.7)	0.01

^aCK = creatine kinase; DM = dermatomyositis; IIM = idiopathic inflammatory myopathy; PM = polymyositis. ^bIncludes CK values (if available) within 3 months of IIM diagnosis. Results are expressed as means ± SD or number (%).

ISSN: 1478-6362