Table 2.

Performance of log-transformed FGF-21 z-scores for diagnosing mitochondrial disease. FGF-21 z-scores refer to thresholds. Figures in brackets are 95% confidence intervals. PV is predictive value.

FGF-21 z-Score	Sensitivity	Specificity	Positive PV	Negative PV
1.35	0.65 (0.55–0.74)	0.70 (0.50–0.86)	0.90	0.35
2.82	0.20 (0.13–0.29)	0.93 (0.76–0.99)	0.91	0.23