Exclusionary and confirming HRP cut-off points with polysomnographic AHI cut-off points of ≥5, ≥10 and ≥15
Selectivity | Specificity | LR+ (95% CI) | Post-test probability+ (95% CI) | LR− (95% CI) | Post-test probability− (95% CI) | HRP+/−, % | |
To AHI ≥5 from PSG (pretest probability 90%) | |||||||
≥5 | 96 | 57 | 2.23 (1.78 to 2.79) | 95 (94 to 96) | 0.07 (0.05 to 0.10) | 39 (31 to 47) | 90/10 |
≥10 | 87 | 86 | 6,25 (2.73 to 14) | 98 (96 to 99) | 0.15 (0.11 to 0.21) | 57 (50 to 65) | 80/20 |
To AHI ≥10 from PSG (pretest probability 82%) | |||||||
≥5 | 97 | 39 | 1.59 (1.30 to 1.94) | 88 (86 to 90) | 0.08 (0.04 to 0.16) | 27 (15 to 42) | 90/10 |
≥20 | 71 | 90 | 7.10 (3.37 to 15) | 97 (94 to 99) | 0.32 (0.26 to 0.39) | 59 (54 to 64) | 60/40 |
To AHI ≥15 from PSG (pretest probability 75%) | |||||||
≥10 | 94 | 60 | 2.35 (1.81 to 3.05) | 88 (84 to 90) | 0.10 (0.06 to 0.17) | 23 (15 to 34) | 80/20 |
≥25 | 67 | 92 | 8.36 (4.09 to 17) | 96 (92 to 98) | 0.36 (0.30 to 0.44) | 52 (47 to 57) | 52/48 |
AHI, apnoea-hypopnoea index; HRP, home respiratory polygraphy; HRP +/−, %, percentage of patients with a positive/negative diagnosis based on HRP; LR, likelihood ratio; post-test probability +, the post-test probability of obtaining a true positive diagnosis when the test (HRP) was positive; post-test probability −, the post-test probability of obtaining a true positive diagnosis when the test (HRP) was negative.