Table 3.
Diagnostic performance characteristics for other thresholds of serum potassium values at presentation to an emergency department and at hospital admission
| ICD-10 E87.5 coding algorithm | Emergency department |
Hospital admission (mmol/l) |
|||||
|---|---|---|---|---|---|---|---|
| >5 | >6 | >6.5 | >5 | >6 | >6.5 | ||
| Per cent (95% CI) | Per cent (95% CI) | Per cent (95% CI) | Per cent (95% CI) | Per cent (95% CI) | Per cent (95% CI) | ||
| All diagnoses | Sn | 6.55 (5.84 to 7.35) | 19.32 (16.73 to 22.21) | 21.81 (18.17 to 25.95) | 7.50 (6.83 to 8.22) | 23.34 (20.95 to 25.91) | 29.49 (25.76 to 33.51) |
| Sp | 99.98 (99.96 to 99.98) | 99.79 (99.76 to 99.83) | 99.70 (99.66 to 99.74) | 99.79 (99.75 to 99.82) | 99.56 (99.50 to 99.61) | 99.40 (99.34 to 99.46) | |
| PPV | 94.74 (91.50 to 96.78) | 54.04 (48.23 to 59.73) | 32.98 (27.78 to 38.64) | 76.85 (73.11 to 80.21) | 48.15 (43.96 to 52.36) | 28.89 (25.23 to 32.85) | |
| NPV | 94.01 (93.83 to 94.19) | 99.00 (98.92 to 99.07) | 99.48 (99.42 to 99.53) | 92.00 (91.78 to 92.20) | 98.66 (98.57 to 98.75) | 99.42 (99.35 to 99.47) | |
| Main/most responsible diagnosis | Sn | 2.65 (2.20 to 3.18) | 8.53 (6.79 to 10.68) | 9.05 (6.69 to 12.13) | 1.16 (0.91 to 1.47) | 4.94 (3.81 to 6.37) | 7.94 (5.93 to 10.56) |
| Sp | 99.99 (99.97 to 99.99) | 99.92 (99.90 to 99.94) | 99.88 (99.85 to 99.90) | 99.99 (99.99 to 100) | 99.98 (99.97 to 99.99) | 99.96 (99.94 to 99.97) | |
| PPV | 93.16 (87.09 to 96.49) | 58.12 (49.06 to 66.66) | 33.33 (25.44 to 42.28) | 95.52 (87.64 to 98.47) | 82.09 (71.25 to 89.45) | 62.69 (50.72 to 73.28) | |
| NPV | 93.78 (93.59 to 93.96) | 98.87 (98.78 to 98.95) | 99.39 (99.33 to 99.45) | 91.51 (91.29 to 91.72) | 98.36 (98.26 to 98.45) | 99.24 (99.17 to 99.31) | |
| Preadmit diagnosis | 5.84 (5.25 to 6.49) | 19.93 (17.69 to 22.38) | 25.71 (22.17 to 29.60) | ||||
| 99.92 (99.89 to 99.94) | 99.77 (99.73 to 99.80) | 99.63 (99.58 to 99.68) | |||||
| 87.30 (83.52 to 90.31) | 60.00 (54.93 to 64.86) | 36.76 (32.00 to 41.78) | |||||
| 91.87 (91.66 to 92.08) | 98.61 (98.52 to 98.70) | 99.39 (99.32 to 99.44) | |||||
ICD-10, International Classification of Diseases, 10th revision; NPV, negative-predictive value: PPV, positive-predictive value; Sn, sensitivity; Sp, specificity.