Myostatin Levels and the Risk of Myopenia and Rheumatoid Cachexia in Women with Rheumatoid Arthritis

Table 4

Utility values of myostatin  ng/mL, for a biomarker of low muscle mass and rheumatoid cachexia.

Utility values of the assay	Low muscle mass	Rheumatoid cachexia
Sensitivity, % (95% CI)	43 (32-54)	53 (34-72)
Specificity, % (95% CI)	77 (66-86)	71 (62-79)
Positive predictive value, % (95% CI)	69 (57-78)	30 (22-39)
Negative predictive value, % (95% CI)	54 (49-60)	87 (82-91)
LR+	1.89 (1.17-3.08)	1.83 (1.19-2.82)
LR-	0.74 (0.59-0.91)	0.65 (0.44-0.97)
Prevalence	53 (45-61)	19 (13-26)

LR+: positive likelihood ratio; LR-: negative likelihood ratio.