Minimal clinically important difference in maxillofacial trauma patients: a prospective cohort study.

The present study estimated the minimal clinically important difference (MCID) for pain on a visual analogue scale - numerical rating scale (VAS-NRS) and mean bite force (MBF) in patients treated for maxillofacial trauma (MFT). This cohort study included 120 MFT patients treated according to AO principles. Preoperative and four-week postoperative pain on the VAS-NRS, and MBF were measured to calculate MCIDs as indicators of functional rehabilitation. The patient's perspective of the treatment was assessed using a four-item anchor question. The MCID was determined by two anchor-based approaches, namely, the change difference (CD) method and receiver operating characteristic (ROC) curve method. According to the CD method, the MCID for pain was 2.4 and the MBF was 147.9 N. Based on the ROC curve, the MCID for pain was 2.5 (sensitivity 91.7%, specificity 47.2%) and MBF was 159.1 N (sensitivity 71.4%, specificity 61.1%). This study demonstrated a high sensitivity (>70%) for MCID, which implies that pain reduction of 2.4-2.5 points on the VAS-NRS and a gain in MBF of 147.9-159.1N are clinically relevant for patients treated for MFT.