Background: An increasing number of patients are seeking neck rejuvenation treatments, and different brands of HA fillers can be used to treat horizontal neck lines with favourable results. However, validated, standardized scales to grade the severity of horizontal neck wrinkles are lacking. Aim: to describe the development and validation of the 5-grade photographic IBSA Neck Lines Scale. Methods: 2 photographs were selected to create 5 morphed images of increasing visibility of the lines on the neck anatomical area. Fifty images of which half morphed and half real-life, were validated and assessed according to a 5-image scale by 5 experts who had previously undergone a specific training split into 2 rounds, 30 days apart, with the aim of evaluating inter- and intra-rater reliability. Results: Single-rater kappa scores ranging between 0.63 and 0.82, and a global kappa score of 0.75 were calculated as to intra-rater reliability, whereas when inter-rater agreement was assessed by an intra-class correlation coefficient, scores higher than 0.85 were observed. These results indicate excellent reliability. Conclusions: The IBSA Neck Lines Scale has proven to be a reliable and consistent assessment tool.
Key words: neck lines, photographic scale, aesthetic medicine, scale development, scale validation