. 2007 Jun 6;12(2):145–152. doi: 10.1111/j.1542-474X.2007.00153.x

Table 5.

Reproducibility of QTo Measurements: Mean Difference Between Measurements, Standard Deviation of the Difference, and Coefficient of Variability According to Measurement Method

Method	Average of Pairs (ms)	Mean Difference Between Pairs (ms)	P (Mean Difference)	SD of Mean Difference (ms)	Coefficient of Variability (%)
Global QTo	388	2.66	0.004	6.14	1.58
Representative QTo II, baseline	379	0.73	0.687	12.67	3.34
Representative QTo II, tangent	379	2.27	0.026	6.91	1.83
Representative QTo V₂, baseline	375	−0.12	0.919	8.32	2.22
Representative QTo V₂, tangent	373	−0.58	0.525	6.40	1.72
Representative QTo V₃, baseline	381	−0.90	0.495	9.13	2.40
Representative QTo V₃, tangent	378	0.60	0.649	9.28	2.45

P = Significance of mean difference between paired measurements; coefficient of variability = 100 × SD of mean difference/average of paired measurements.