A clinimetric assessment of the validity and reliability of 3D technology for scar surface area measurement.

INTRODUCTION: The quality of scars has become an important outcome of burn care. Objective scar assessment through scar surface area measurement enables quantification of scar formation and evaluation of treatment efficacy. 3D technology has proven valid and reliable but often remains cumbersome, expensive, and time-consuming. 3D technology with depth sensors on mobile devices has become available and might surpass these limitations. This study provides a clinimetric assessment of the validity and reliability of a 3D system with a depth sensor for scar surface area measurement. METHODS: A technology involving a depth sensor mounted on a mobile device was used. Images and analyses were made with a custom-made software application. A standardized one-keyframe image capturing procedure was followed. To assess validity, stickers with predefined dimensions (8.01 cm2 - 77.70 cm2) were imaged in a single observer setting on various body parts of healthy volunteers. To assess reliability, hypertrophic scars, keloids, and normotrophic scars were imaged and rated by two observers independently. Data are expressed as mean (+/-SD), Coefficient of Variation (CV), Intraclass Correlation Coefficients (ICC), and Limits of Agreements (LoA). RESULTS: Eighty stickers placed on 20 healthy volunteers showed validity with CV between 0.62%- 1.67% for observer A and 0.75%- 1.19% for observer B. For the reliability study, 69 scars on 36 patients were included. Mean scar surface area ranged from 0.83 cm2 to 155.59 cm2. Mean scar surface area measurement was 13.83 cm2 (SD 23.06) for observer A and 13.59 cm2 (SD 23.31) for observer B. Adjusted interobserver CV for trained observers is estimated as 5.59%, with corresponding LoA = 0 ± 0.15 x mean surface area. Interobserver ICCs were 0.99-1.00. CONCLUSION: This 3D technology with a depth sensor for measuring scar surface area provides valid and reliable data and thereby surpasses expensive and time-consuming 3D cameras.

Comparison of two scoring systems in the assessment of nasolabial appearance in cleft lip and palate patients.

OBJECTIVE: The aim of this study was to determine the reliability of 2 scoring systems. DESIGN: This study used a retrospective analysis of the results of complete unilateral cleft lip and palate patients. SETTING: The study was conducted at the VU Medical Center and the Academic Center for Dentistry of Amsterdam. PATIENTS: Patients were complete unilateral cleft lip and palate patients at the age of 6 years. MAIN OUTCOME MEASURES: Assessment of the nose and lip together and separately with a numerical photographic reference scoring system and with a 5-point ordinal scale without the use of a reference photograph by 6 judges. Intraobserver and interobserver reliability was calculated; both ways of assessment were compared by using Kendall tau. RESULTS: Photographs were available of 55 children (6 years old, 38 boys and 17 girls) with a complete unilateral cleft lip and palate. The interobserver reliabilities of the lip and nose together were 0.53 and, for the nose and lip separately, 0.51 and 0.43, respectively with the use of the numerical scale. In the 5-point scale, these were 0.55 for the nose and lip together and 0.57 and 0.45 for the nose and lip separately, respectively. Furthermore, it was found that the lip dominates in the scorings of the lip and nose together (linear regression analysis). CONCLUSIONS: The 2 tested systems are equivalent in their reliability and outcome. The lip is dominating in the overall scorings. It is advocated to use the 5-point scale without the use of a reference photograph and to assess the lip and nose separately.