Table 7:
Validity of DPC data for identifying hypernatremia based on various cutoff values and the timing of the registered diagnosis, in stratified and sensitivity analyses.
| Type of analysis, strata, or conditions | Timing | Cutoff, mmol/L | Disease frequency based on sodium data (%) | Diagnosis frequency based on DPC data (%) | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) | LR+ | LR− | DOR |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Aged <75 years | During hospitalization | >145 | 4.1 | 0.1 | 1.4 | >99.9 | 94.5 | 95.9 | 396 | 0.99 | 402 |
| (N = 906 159) | >150 | 1.0 | 0.1 | 5.1 | >99.9 | 81.8 | 99.1 | 448 | 0.95 | 472 | |
| >155 | 0.5 | 0.1 | 8.6 | >99.9 | 64.8 | 99.6 | 391 | 0.92 | 428 | ||
| On admission day | >145 | 1.7 | 0.0 | 2.6 | >99.9 | 88.6 | 98.4 | 454 | 0.97 | 466 | |
| (N = 625 261) | >150 | 0.3 | 0.0 | 13.2 | >99.9 | 73.3 | 99.8 | 1005 | 0.87 | 1158 | |
| >155 | 0.1 | 0.0 | 22.4 | >99.9 | 55.7 | 99.9 | 1028 | 0.78 | 1324 | ||
| After admission day | >145 | 4.2 | 0.0 | 0.7 | >99.9 | 94.8 | 95.8 | 416 | 0.99 | 418 | |
| (N = 730 701) | >150 | 1.1 | 0.0 | 2.1 | >99.9 | 82.9 | 98.9 | 424 | 0.98 | 433 | |
| >155 | 0.5 | 0.0 | 3.5 | >99.9 | 64.5 | 99.5 | 336 | 0.97 | 348 | ||
| Aged ≥75 years | During hospitalization | >145 | 10.5 | 0.3 | 2.4 | >99.9 | 97.0 | 89.7 | 275 | 0.98 | 281 |
| (N = 907 197) | >150 | 3.8 | 0.3 | 6.1 | >99.9 | 87.5 | 96.4 | 177 | 0.94 | 188 | |
| >155 | 1.9 | 0.3 | 9.5 | 99.9 | 69.7 | 98.2 | 117 | 0.91 | 129 | ||
| On admission day | >145 | 3.7 | 0.2 | 5.0 | >99.9 | 92.1 | 96.5 | 303 | 0.95 | 319 | |
| (N = 726 499) | >150 | 1.1 | 0.2 | 14.5 | >99.9 | 81.1 | 99.0 | 378 | 0.86 | 442 | |
| >155 | 0.6 | 0.2 | 21.6 | 99.9 | 63.0 | 99.5 | 288 | 0.79 | 368 | ||
| After admission day | >145 | 10.8 | 0.1 | 0.9 | >99.9 | 96.9 | 89.2 | 258 | 0.99 | 260 | |
| (N = 773 620) | >150 | 4.1 | 0.1 | 2.0 | >99.9 | 83.9 | 96.0 | 121 | 0.98 | 124 | |
| >155 | 2.1 | 0.1 | 3.0 | >99.9 | 61.9 | 98.0 | 77 | 0.97 | 79 | ||
| Analysis stratified by | During hospitalization | >145 | 3.7 | 0.0 | 0.7 | >99.9 | 92.5 | 96.4 | 322 | 0.99 | 325 |
| admission-necessitating | (N = 335 296) | >150 | 0.9 | 0.0 | 2.5 | >99.9 | 81.7 | 99.1 | 483 | 0.98 | 495 |
| diagnosis, neoplasms | >155 | 0.4 | 0.0 | 3.6 | >99.9 | 57.0 | 99.6 | 300 | 0.96 | 311 | |
| On admission day | >145 | 1.7 | 0.0 | 0.6 | >99.9 | 71.4 | 98.3 | 147 | 0.99 | 148 | |
| (N = 194 310) | >150 | 0.2 | 0.0 | 3.2 | >99.9 | 50.0 | 99.8 | 445 | 0.97 | 459 | |
| >155 | 0.1 | 0.0 | 2.3 | >99.9 | 14.3 | 99.9 | 188 | 0.98 | 193 | ||
| After admission day | >145 | 3.7 | 0.0 | 0.6 | >99.9 | 98.2 | 96.4 | 1445 | 0.99 | 1453 | |
| (N = 270 295) | >150 | 1.0 | 0.0 | 1.8 | >99.9 | 89.3 | 99.0 | 792 | 0.98 | 806 | |
| >155 | 0.5 | 0.0 | 2.7 | >99.9 | 66.1 | 99.5 | 382 | 0.97 | 392 | ||
| Analysis stratified by | During hospitalization | >145 | 10.3 | 0.1 | 0.9 | >99.9 | 96.4 | 89.8 | 230 | 0.99 | 232 |
| admission-necessitating | (N = 361 762) | >150 | 3.3 | 0.1 | 2.5 | >99.9 | 81.5 | 96.8 | 130 | 0.98 | 134 |
| diagnosis, cardiovascular | >155 | 1.6 | 0.1 | 3.8 | >99.9 | 60.2 | 98.5 | 96 | 0.96 | 100 | |
| On admission day | >145 | 3.0 | 0.0 | 0.8 | >99.9 | 70.1 | 97.0 | 76 | 0.99 | 77 | |
| (N = 300 913) | >150 | 0.5 | 0.0 | 3.7 | >99.9 | 51.4 | 99.5 | 213 | 0.96 | 221 | |
| >155 | 0.2 | 0.0 | 6.4 | >99.9 | 34.6 | 99.8 | 274 | 0.94 | 292 | ||
| After admission day | >145 | 11.1 | 0.1 | 0.7 | >99.9 | 97.1 | 88.9 | 271 | 0.99 | 273 | |
| (N = 289 463) | >150 | 3.8 | 0.1 | 1.9 | >99.9 | 84.1 | 96.3 | 134 | 0.98 | 136 | |
| >155 | 1.8 | 0.1 | 2.9 | >99.9 | 61.6 | 98.2 | 87 | 0.97 | 89 | ||
| Analysis stratified by | During hospitalization | >145 | 14.2 | 0.4 | 2.5 | >99.9 | 97.1 | 86.1 | 204 | 0.98 | 209 |
| admission-necessitating | (N = 149 954) | >150 | 6.0 | 0.4 | 5.3 | 99.9 | 86.2 | 94.3 | 98 | 0.95 | 103 |
| diagnosis, respiratory | >155 | 3.0 | 0.4 | 8.2 | 99.9 | 67.4 | 97.2 | 66 | 0.92 | 72 | |
| On admission day | >145 | 4.4 | 0.2 | 5.1 | >99.9 | 92.5 | 95.9 | 272 | 0.95 | 286 | |
| (N = 134 818) | >150 | 1.7 | 0.2 | 11.4 | >99.9 | 80.7 | 98.5 | 244 | 0.89 | 275 | |
| >155 | 0.9 | 0.2 | 17.0 | 99.9 | 65.1 | 99.2 | 202 | 0.83 | 243 | ||
| After admission day | >145 | 14.3 | 0.2 | 1.1 | >99.9 | 97.6 | 85.8 | 244 | 0.99 | 247 | |
| (N = 135 778) | >150 | 6.1 | 0.2 | 2.0 | >99.9 | 81.3 | 94.0 | 67 | 0.98 | 68 | |
| >155 | 3.1 | 0.2 | 3.0 | 99.9 | 59.3 | 97.0 | 46 | 0.97 | 48 | ||
| Analysis stratified by | During hospitalization | >145 | 6.4 | 0.2 | 3.1 | >99.9 | 96.6 | 93.8 | 411 | 0.97 | 424 |
| admission-necessitating | (N = 966 344) | >150 | 2.0 | 0.2 | 8.7 | >99.9 | 87.7 | 98.1 | 341 | 0.91 | 374 |
| diagnosis, other | >155 | 1.0 | 0.2 | 13.7 | 99.9 | 71.2 | 99.1 | 234 | 0.86 | 271 | |
| On admission day | >145 | 2.7 | 0.2 | 6.4 | >99.9 | 93.4 | 97.5 | 516 | 0.94 | 551 | |
| (N = 721 719) | >150 | 0.8 | 0.2 | 19.1 | >99.9 | 82.5 | 99.4 | 594 | 0.81 | 733 | |
| >155 | 0.4 | 0.2 | 27.7 | 99.9 | 64.2 | 99.7 | 422 | 0.72 | 583 | ||
| After admission day | >145 | 6.5 | 0.1 | 0.9 | >99.9 | 95.4 | 93.5 | 296 | 0.99 | 299 | |
| (N = 808 785) | >150 | 2.2 | 0.1 | 2.2 | >99.9 | 83.9 | 97.8 | 228 | 0.98 | 233 | |
| >155 | 1.1 | 0.1 | 3.3 | >99.9 | 63.8 | 98.9 | 154 | 0.97 | 159 | ||
| Sensitivity analysis 1, | During hospitalization | >145 | 7.3 | 0.2 | 2.3 | >99.9 | 96.4 | 92.8 | 336 | 0.98 | 343 |
| first-time admissions | (N = 1 156 291) | >150 | 2.5 | 0.2 | 6.1 | >99.9 | 86.2 | 97.7 | 246 | 0.94 | 262 |
| >155 | 1.2 | 0.2 | 9.7 | 99.9 | 68.7 | 98.9 | 176 | 0.90 | 195 | ||
| On admission day | >145 | 2.8 | 0.1 | 4.6 | >99.9 | 92.3 | 97.3 | 412 | 0.95 | 432 | |
| (N = 848 826) | >150 | 0.8 | 0.1 | 14.8 | >99.9 | 79.8 | 99.4 | 519 | 0.85 | 608 | |
| >155 | 0.4 | 0.1 | 22.5 | 99.9 | 61.7 | 99.7 | 419 | 0.78 | 540 | ||
| After admission day | >145 | 7.6 | 0.1 | 0.9 | >99.9 | 96.4 | 92.4 | 324 | 0.99 | 327 | |
| (N = 964 571) | >150 | 2.7 | 0.1 | 2.2 | >99.9 | 83.7 | 97.3 | 183 | 0.98 | 187 | |
| >155 | 1.4 | 0.1 | 3.3 | >99.9 | 62.9 | 98.7 | 123 | 0.97 | 128 | ||
| Sensitivity analysis 2, | During hospitalization | >145 | 7.2 | 0.2 | 2.0 | >99.9 | 96.2 | 92.9 | 325 | 0.98 | 332 |
| excluding those with | (N = 1 431 877) | >150 | 2.3 | 0.2 | 5.6 | >99.9 | 84.7 | 97.8 | 236 | 0.94 | 250 |
| diabetes, | >155 | 1.1 | 0.2 | 9.1 | 99.9 | 66.4 | 99.0 | 175 | 0.91 | 193 | |
| hypertriglyceridemia, or | On admission day | >145 | 2.8 | 0.1 | 4.1 | >99.9 | 91.4 | 97.3 | 361 | 0.96 | 377 |
| multiple myeloma | (N = 1 068 544) | >150 | 0.7 | 0.1 | 14.0 | >99.9 | 78.9 | 99.4 | 520 | 0.86 | 605 |
| >155 | 0.4 | 0.1 | 21.8 | >99.9 | 60.9 | 99.7 | 438 | 0.78 | 560 | ||
| After admission day | >145 | 7.5 | 0.1 | 0.7 | >99.9 | 95.7 | 92.6 | 276 | 0.99 | 278 | |
| (N = 1 173 835) | >150 | 2.6 | 0.1 | 1.8 | >99.9 | 80.9 | 97.5 | 162 | 0.98 | 165 | |
| >155 | 1.2 | 0.1 | 2.7 | >99.9 | 58.1 | 98.8 | 111 | 0.97 | 114 |
DPC, Diagnosis Procedure Combination; NPV, negative predictive value; PPV, positive predictive value; LR+: positive likelihood ratio; LR−: negative likelihood ratio; DOR: diagnostic odds ratio