Fig. 2

Bland–Altman plot showing the intra-reader and inter-reader repeated RPD measurements. The mean difference between the two intra-reader reads was 0.98 (95 % CI 0.47–1.50). Pitman’s test of difference in variance was negative suggesting little bias (p = 0.66) (a). The mean difference between the two inter-reader reads was 0.04 (95 % CI −0.59 to 0.67). Pitman’s test of difference in variance was negative (p = 0.64) (b)