Diagnostic performance characteristics for ICD-10 E87.5 coding algorithms for hyperkalaemia defined by a serum potassium value >5.5 mmol/l at presentation to an emergency department and at hospital admission
| Emergency department | Hospital admission | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| ICD-10 E87.5 coding algorithm | + | − | Per cent (95% CI) | + | − | Per cent (95% CI) | ||||
| All diagnoses | + | 237 | 48 | Sn | 14.12 (12.53 to 15.86) | + | 335 | 205 | Sn | 14.64 (13.25 to 16.14) |
| − | 1442 | 62852 | Sp | 99.92 (99.90 to 99.94) | − | 1954 | 62003 | Sp | 99.67 (99.62 to 99.71) | |
| PPV | 83.16 (78.38 to 87.06) | PPV | 62.04 (57.87 to 66.03) | |||||||
| NPV | 97.76 (97.64 to 97.87) | NPV | 96.94 (96.81 to 97.08) | |||||||
| + | − | + | − | |||||||
| Main/most responsible diagnosis | + | 98 | 19 | Sn | 5.84 (4.81 to 7.06) | + | 59 | 8 | Sn | 2.58 (2.00 to 3.31%) |
| − | 1581 | 62881 | Sp | 99.97 (99.95 to 99.98) | − | 2230 | 62200 | Sp | 99.99 (99.97 to 99.99) | |
| PPV | 83.76 (76.03 to 89.35) | PPV | 88.06 (78.17 to 93.82) | |||||||
| NPV | 97.55 (97.43 to 97.66) | NPV | 96.54 (96.39 to 96.68) | |||||||
| + | − | |||||||||
| Preadmit diagnosis | + | 276 | 94 | Sn | 12.06 (10.79 to 13.46) | |||||
| − | 2013 | 62 114 | Sp | 99.85 (99.82 to 99.88) | ||||||
| PPV | 74.59 (69.92 to 78.76) | |||||||||
| NPV | 96.86 (96.72 to 96.99) | |||||||||
+, Hyperkalaemia yes; −, hyperkalaemia no; ICD-10, International Classification of Diseases, 10th revision; NPV, negative-predictive value; PPV, positive-predictive value; Sn, sensitivity; Sp, specificity.