Table 6:
Validity of DPC data for identifying hypernatremia based on various cutoff values and the timing of the registered diagnosis.
| Timing | Cutoff, mmol/L | Disease frequency based on sodium data (%) | Diagnosis frequency based on DPC data (%) | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) | LR+ | LR− | DOR |
|---|---|---|---|---|---|---|---|---|---|---|
| During | >145 | 7.3 | 0.2 | 2.2 | >99.9 | 96.5 | 92.8 | 350 | 0.98 | 358 |
| hospitalization | >150 | 2.4 | 0.2 | 5.9 | >99.9 | 86.4 | 97.7 | 259 | 0.94 | 275 |
| (N = 1 813 356) | >155 | 1.2 | 0.2 | 9.3 | 99.9 | 68.7 | 98.9 | 181 | 0.91 | 200 |
| On admission day | >145 | 2.8 | 0.1 | 4.3 | >99.9 | 91.5 | 97.4 | 378 | 0.96 | 395 |
| (N = 1 351 760) | >150 | 0.7 | 0.1 | 14.3 | >99.9 | 79.8 | 99.4 | 536 | 0.86 | 625 |
| >155 | 0.4 | 0.1 | 21.7 | 99.9 | 61.8 | 99.7 | 432 | 0.78 | 552 | |
| After admission day | >145 | 7.6 | 0.1 | 0.8 | >99.9 | 96.5 | 92.4 | 330 | 0.99 | 333 |
| (N = 1 504 321) | >150 | 2.7 | 0.1 | 2.1 | >99.9 | 83.7 | 97.4 | 187 | 0.98 | 191 |
| >155 | 1.3 | 0.1 | 3.1 | >99.9 | 62.4 | 98.7 | 124 | 0.97 | 128 |
DPC, Diagnosis Procedure Combination; NPV, negative predictive value; PPV, positive predictive value; LR+: positive likelihood ratio; LR−: negative likelihood ratio; DOR: diagnostic odds ratio