Prewebinar survey DIF detection procedure for ordinal data based on adjacent category logit model: likelihood ratio using χ2 analysis.
| Procedure | Statistica | P | Adjusted P |
| UBE STEN | 1.177 | 0.555 | 0.818 |
| PEID | 3.651 | 0.161 | 0.806 |
| UBE LAM HNP | 0.848 | 0.654 | 0.818 |
| UBE LAM STEN | 0.312 | 0.856 | 0.856 |
| Endo + ISP | 1.027 | 0.598 | 0.818 |
Abbreviations: DIF, differential item functioning; Endo + ISP, transforaminal endoscopic decompression with simultaneous interspinous process spacer for lateral canal stenosis; PEID STEN, percutaneous interlaminar endoscopic decompression for lateral canal stenosis; UBE LAM HNP, unilateral biportal endoscopic laminectomy for herniated disc; UBE LAM STEN, unilateral biportal endoscopic laminectomy for central stenosis; UBE STEN, unilateral biportal endoscopic decompression for lateral canal stenosis.
Note. The adjusted P values were adjusted by likelihood ratio test using multiple comparison.
↵a DIF likelihood ratio statistics are estimated by using difNLR and difORD function.