Table 1. Bland and Altman method comparing each real-time (RT) observation method with image (IMG) scores.

Observation type	Bias	Upper limit	Lower limit
RT-interval10	−0.09	0.46	−0.63
RT-interval5	−0.11	0.44	−0.65
RT-interval2	−0.14	0.43	−0.71
RT-point10	−0.07	0.49	−0.63
RT-point5	−0.08	0.47	−0.63
RT-point2	−0.09	0.50	−0.68

Bias is the mean difference between RT and IMG Rat Grimace Scale scores. Upper and lower limits of agreement are mean difference ± 2 SD.