Table 7
Change in the complexity of lesions across eras (fig 1): χ
2
cells
Era 1
Era 2
Era 3
χ
2
= 12.595 with df = 4.
χ
2
p = 0.0134.
Simple
2.345
0.211
4.312
Moderate
1.423
0.367
3.511
Complex
0.246
0.011
0.169