Table 3.
Validity of key variables registered in DKRR
| DKRR database | Medical record
|
Missing medical record | PPV% (95% CI) | ||
|---|---|---|---|---|---|
| Yes | No | ||||
| Cartilage lesion | Yes | 29 | 5 | 0 | 29/34 = 85 (69–95) |
| No | 27 | 127 | 12 | ||
| Missing DKRR | 13 | 26 | 1 | ||
| Treated meniscal lesionsa | Yes | 103 | 4 | 0 | 103/107 = 96 (90–99) |
| No | 26 | 107 | 0 | ||
| Sport as activity reason for the ACL rupture | Yes | 172 | 29 | 1 | 172/201 = 86 (80–90) |
| No | 4 | 33 | 0 | ||
| Missing DKRR | 0 | 1 | 0 | ||
| Diagnosis of ACL lesion | Yes | 240 | 0 | 240/240 = 100 | |
| No | 0 | 0 | |||
| Hamstring as graft choiceb | Yes | 208 | 0 | 2 | 208/208 = 100 |
| No | 0 | 24 | 0 | ||
| Missing DKRR | 4 | 1 | 1 | ||
| Transtibial placement of femoral canal | Yes | 136 | 6 | 60 | 136/142 = 96 (91–98) |
| No | 3 | 18 | 16 | ||
| Missing DKRR | 1 | 0 | 0 | ||
| One femoral canal (versus two) | Yes | 237 | 0 | 2 | 237/237 = 100 |
| No | 0 | 0 | 0 | ||
| Missing DKRR | 1 | 0 | 0 | ||
| OP date | Identical | 238 | 0 | 1 | 238/239 = 99 (93–100) |
| Not identical | 0 | 1 | |||
| Method for fixation of graft in femur | Identical | 217 | 7 | 217/233 = 93 (89–96)c | |
| Method for fixation of graft in tibia | Identical | 220 | 6 | 220/234 = 94 (90–97)c | |
Notes: Medical records were used as a reference standard, and 240 medical records were used. “Identical” indicates that the registration in the DKRR is identical to the registration in the medical records.
The registration of this variable in DKRR is to choose a treatment of the meniscal lesion. Hence, if no registration is made in this variable it can be etiher: no treatment or a missing value
comparing if hamstring or bone–patellar tendon–bone graft is used. Other graft choices were deleted because they account for less than 2%
About 20 different modes of fixation are possible in this variable. Therefore, calculation of completeness was made by inputing the number of variables registered identical in the DKRR and in the medical records into the numerator, and dividing them by all the cases registered in the denominator.
Abbreviations: DKRR, Danish Knee Ligament Reconstruction Register; PPV, positive predictive value; CI, confidence interval; ACL, anterior cruciate ligament; OP, operation.