CPN	IAH <5	IAH 5–15	IAH 15–30	IAH >30
<43 (n=61)	17 (28%)	22 (36%)	8 (13%)	14 (23%)
43–48 (n=112)	18 (16%)	28 (25%)	29 (28%)	37 (33%)
>48 (n=164)	6 (4%)	30 (18%)	34 (21%)	94 (57%)