Table 3.

Diagnostic test performance of plasma metanephrines with different upper cut-offs and models adjusting for age

Model	Upper cut-offs (nmol/L)		Test performance
	NMN	MN	Sensitivity (%)	Specificity (%)
Fixed – 97.5 percentiles	0.706	0.325	93.9*	88.3*
Age-dependent linear model	Variable	0.325	93.9*	91.2†
Age-dependent curvilinear model	Variable	0.325	93.7*	93.6§
Age-dependent curvilinear model	Variable	0.446	93.6*	96.0¶
Age-adjusted score model	NA	NA	79.5†	99.9#

NMN, normetanephrine; MN, metanephrine; NA, not applicable (based on a score)

Presence of different symbols (*^†§¶#) indicates differences (P < 0.0003) in sensitivity or specificity among different models. Presence of the same symbol indicates no difference

Variable upper cut-offs for plasma NMN (UC_NMN) for the age-dependent linear model were defined by the equation UC_NMN = 7.99 × 10⁻³age + 0.358

Variable upper cut-offs for plasma NMN for the age-dependent curvilinear model were defined by the equation UC_NMN = 2.07 × 10⁻⁶ age³ + 0.540 and are shown for two upper cut-offs for MN

The age-adjusted scored model is defined by the equation [−4.188 + −0.07age + 4.516MN + 3.129NMN] as described by Sawka et al.²⁷