Fig. 1
Bland Altman plot representation of the test-retest reliability, the difference against the mean of the Keele Start Back Tool (SBT) total score (left) and psychosocial subscores (right). Mean of the difference ± standard deviation was -0.2 ± 0.8 and 0.07 ± 0.7 for total score and psychosocial subscore respectively. The solid line represents mean difference. Dotted line represents limits of agreement (LoA) = mean difference ± 1.96 x SDdiff (-0.2 ± 1.96x0.8 = -1.8, 1.4 and 0.07 ± 1.96x0.7 = -1.3, 1.4 for the total score and the psychosocial subscore respectively)