From qualitative data to a measurement instrument: A clarification and elaboration of choices made in the development of the Patient Scale of the Patient and Observer Scar Assessment Scale (POSAS) 3.0.

PURPOSE: To clarify and elaborate on the choices that were made in the development of the Patient Scale of the Patient and Observer Scar Assessment Scale 3.0 (POSAS 3.0), based upon the rich information obtained from patients during focus groups and pilot tests. METHODS: The discussions described in this paper are a reflection of the focus group study and pilot tests that were conducted in order to develop the Patient Scale of the POSAS3.0. The focus groups took place in the Netherlands and Australia and included 45 participants. Pilot tests were performed with 15 participants in Australia, the Netherlands, and the United Kingdom. RESULTS: We discussed the selection, wording and merging of 17 included items. Additionally, the reason for exclusion of 23 characteristics are given. CONCLUSION: Based upon the unique and rich material of patient input obtained, two versions of the Patient Scale of the POSAS3.0 were developed: the Generic version, and the Linear scar version. The discussions and decisions taken during the development are informative for a good understanding of the POSAS 3.0 and are indispensable as a background for future translations and cross-cultural adaptations.

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.

Development of the Patient Scale of the Patient and Observer Scar Assessment Scale (POSAS) 3.0: a qualitative study.

PURPOSE: The Patient and Observer Scar Assessment Scale (POSAS) is widely used for measurements of scar quality. This encompasses visual, tactile and sensory characteristics of the scar. The Patient Scale of previous POSAS versions was lacking input from patients. Therefore, the aim of this study was to develop the POSAS3.0, Patient Scale with involvement of adults patients with all scar types, complying with the highest clinimetric standards. METHODS: From February 2018 to April 2019, a series of six focus group interviews were performed in the Netherlands and Australia to identify scar quality characteristics that adults with scars consider to be important. All focus groups were transcribed, anonymized and analysed using a thematic analysis. Relevant characteristics were formulated into items, resulting in a Dutch and English version of the Patient Scale. These drafts were pilot tested in Australia, the Netherlands and the United Kingdom, and refined accordingly. RESULTS: A total of 21 relevant scar quality characteristics were identified during the focus groups. Two distinct versions of the POSAS3.0, Patient Scale were developed. The Generic version contains 16 items and can be used for all scar types, except linear scars. The Linear Scar version of the Patient Scale contains the same 16 items, with an extra item referring to the widening of scar margins. All included items are rated on a verbal rating scale with five response options. CONCLUSION: Two versions of the POSAS3.0 Patient Scale were developed. Further field tests are being performed to establish the measurement properties and scoring algorithm of the scales.

The FLIR ONE thermal imager for the assessment of burn wounds: Reliability and validity study.

BACKGROUND: Objective measurement tools may be of great value to provide early and reliable burn wound assessment. Thermal imaging is an easy, accessible and objective technique, which measures skin temperature as an indicator of tissue perfusion. These thermal images might be helpful in the assessment of burn wounds. However, before implementation of a novel measurement tool into clinical practice is considered, it is appropriate to test its clinimetric properties (i.e. reliability and validity). The objective of this study was to assess the reliability and validity of the recently introduced FLIR ONE thermal imager. MATERIAL AND METHODS: Two observers obtained thermal images of burn wounds in adult patients at day 1-3, 4-7 and 8-10 after burn. Subsequently, temperature differences between the burn wound and healthy skin (ΔT) were calculated on an iPad mini containing the FLIR Tools app. To assess reliability, ΔT values of both observers were compared by calculating the intraclass correlation coefficient (ICC) and measurement error parameters. To assess validity, the ΔT values of the first observer were compared to the registered healing time of the burn wounds, which was specified into three categories: (I) ≤14 days, (II) 15-21 days and (III) >21 days. The ability of the FLIR ONE to discriminate between healing ≤21 days and >21 days was evaluated by means of a receiver operating characteristic curve and an optimal ΔT cut-off value. RESULTS: Reliability: ICCs were 0.99 for each time point, indicating excellent reliability up to 10 days after burn. The standard error of measurement varied between 0.17-0.22°C. VALIDITY: the area under the curve was calculated at 0.69 (95% CI 0.54-0.84). A cut-off value of -1.15°C shows a moderate discrimination between burn wound healing ≤21 days and >21 days (46% sensitivity; 82% specificity). CONCLUSION: Our results show that the FLIR ONE thermal imager is highly reliable, but the moderate validity calls for additional research. However, the FLIR ONE is pre-eminently feasible, allowing easy and fast measurements in clinical burn practice.

Predictive validity of short term scar quality on final burn scar outcome using the Patient and Observer Scar Assessment Scale in patients with minor to moderate burn severity.

BACKGROUND: The aim of this study was to assess the predictive validity of the Patient and Observer Assessment Scale (POSAS), in order to determine whether it can be used to predict final scar quality. METHODS: Patients with a maximum TBSA burned of 20% who were treated in a Dutch burn center and participated in two scar assessments at 3 months and >18 months post-burn were included. Scar quality assessment consisted of the POSAS, Dermaspectrometer® (color) and Cutometer® (elasticity). Predictive validity was determined in three ways: (1) the discriminative ability to distinguish good from reduced long term scar quality, (2) correlations between POSAS items score at the two subsequent assessments and (3) linear regression was conducted to identify POSAS items as independent predictors. Additionally, reliability, construct validity and interpretability were assessed. RESULTS: A total of 141 patients were included with a mean TBSA burned of 5.2% (±4.5). The ability of the Patient scale to discriminate between good and reduced long term scar quality was adequate with an area under the curve (AUC) of 0.728 (CI 0.640-0.804), the ability of the Observer scale was good with an AUC of 0.854 (CI 0.781-0.911). Correlations between items scored T3 and T>18 were at least adequate. On item level, pain and stiffness (Patient) and pliability and relief (Observer) were identified as significant predictors for reduced long term scar quality. The POSAS was reliable, construct validity was adequate at three months but declined at >18 months. CONCLUSION: This study found that final scar quality can be adequately predicted by an early POSAS assessment at three months.

Reconstructive surgery after burns: a 10-year follow-up study.

BACKGROUND: There is minimal insight into the prevalence of reconstructive surgery after burns. The objective of this study was to analyse the prevalence, predictors, indications, techniques and medical costs of reconstructive surgery after burns. METHODS: A retrospective cohort study was conducted in the three Dutch burn centres. Patients with acute burns, admitted from January 1998 until December 2001, were included. Data on patient and injury characteristics and reconstructive surgery details were collected in a 10-year follow-up period. RESULTS: In 13.0% (n=229/1768) of the patients with burns, reconstructive surgery was performed during the 10-year follow-up period. Mean number of reconstructive procedure per patient were 3.6 (range 1-25). Frequently reconstructed locations were hands and head/neck. The most important indication was scar contracture and the most applied technique was release plus random flaps/skin grafting. Mean medical costs of reconstructive surgery per patient over 10-years were €8342. CONCLUSIONS: With this study we elucidated the reconstructive needs of patients after burns. The data presented can be used as reference in future studies that aim to improve scar quality of burns and decrease the need for reconstructive surgery.

Digital image analysis versus clinical assessment of wound epithelialization: a validation study.

To evaluate the progress in wound healing, wound assessment is mandatory. Epithelialization is traditionally assessed subjectively by the clinician. In a previous study, subjective assessment of epithelialization was shown to be reliable. In this study, reliability of epithelialization measured by digital image analysis was investigated and then, we validated the subjective evaluation by comparing this assessment to measurements with digital image analysis. Clinicians assessed epithelialization in 50 burn wounds that were treated with a split skin graft. Epithelialization of these wounds was also measured by three observers using digital image analysis. Reliability of digital image analysis was tested using the intraclass correlation (IC). To test validity, subjective clinical assessment was correlated with digital image analysis (IC). The results showed that interobserver reliability of epithelialization measured by digital image analysis was good (IC coefficient 0.74). Subjective clinical assessment of epithelialization showed a strong correlation with digital image analysis (IC coefficient 0.80). In conclusion, subjective clinical evaluation of wound epithelialization is as good as an objective measure, in this study digital image analysis. Since digital image analysis is more time-consuming, we recommend the use of the subjective evaluation for daily practice.

A clinimetric overview of scar assessment scales.

Standardized validated evaluation instruments are mandatory to increase the level of evidence in scar management. Scar assessment scales are potentially suitable for this purpose, but the most appropriate scale still needs to be determined. This review will elaborate on several clinically relevant scar features and critically discuss the currently available scar scales in terms of basic clinimetric requirements. Many current scales can produce reliable measurements but seem to require multiple observers to obtain these results reliably, which limits their feasibility in clinical practice. The validation process of scar scales is hindered by the lack of a "gold standard" in subjective scar assessment or other reliable objective instruments which are necessary for a good comparison. The authors conclude that there are scar scales available that can reliably measure scar quality. However, further research may lead to improvement of their clinimetric properties and enhance the level of evidence in scar research worldwide.

Reliability of subjective wound assessment.

INTRODUCTION: Assessment of the take of split-skin graft and the rate of epithelialisation are important parameters in burn surgery. Such parameters are normally estimated by the clinician in a bedside procedure. This study investigates whether this subjective assessment is reliable for graft take and wound epithelialisation. METHODS: Observers involved in the field of burns (experienced, medium-experienced and inexperienced observers), and dermatologists specialized in the field of wound healing evaluated the percentage graft take and epithelialisation in 50 photographic skin-grafted burn wounds. Reliability was tested using the intraclass correlation coefficient (ICC). RESULTS: Intra- and interobserver reliability of parameter graft take was highest within the experienced observers (ICC average > 0.91), followed by medium- and inexperienced observers (ICC average > 0.80 and ICC average > 0.68). Parameter epithelialisation showed the same pattern of intra- and interobserver ICC scores (experienced > medium > inexperienced). Interobserver ICC single scores of the experienced group were reasonable to good. Interobserver reliability of the dermatologists was similar to medium-experienced observers. CONCLUSIONS: Our data show that one experienced observer can obtain adequate reliable results by means of a single assessment of graft take and epithelialisation. Furthermore, experience of the observer results in an increase of reliability.