Table 4. The diagnostic efficacy of the two-step diagnostic tests.

	Sensitivity(%)	Specificity(%)	PPV (%)	NPV(%)
20.5 as CANRS cut-off value
Abnormal HRB	85.71	63.93	62.07	86.67
Abnormal HRS	69.05	93.44	87.88	81.43
Abnormal Valsalva ratio	54.76	98.36	95.83	75.95
16.5 as CANRS cut-off value
Abnormal HRB	71	88.52	81.08	81.82
Abnormal HRS	98	59.02	62.12	97.30
Abnormal Valsalva ratio	64	96.72	93.10	79.73

HRB, heart rate response to deep breathing; HRS, heart rate response to standing up; CARTs, cardiovascular reflex tests; AUC, area under curve; CANRS, cardiac autonomic neuropathy risk score; PPV, positive prediction value; NPV, negative prediction value.