Rasch analysis of the Patient and Observer Scar Assessment Scale (POSAS) in burn scars

The Patient and Observer Scar Assessment Scale (POSAS) is a questionnaire that was developed to assess scar quality. It consists of two separate six-item scales (Observer Scale and Patient Scale), both of which are scored on a 10-point rating scale. After many years of experience with this scale in burn scar assessment, it is appropriate to examine its psychometric properties using Rasch analysis. Cross-sectional data collection from seven clinical trials resulted in a data set of 1,629 observer scores and 1,427 patient scores of burn scars. We examined the person-item map, item fit statistics, reliability, response category ordering, and dimensionality of the POSAS. The POSAS showed an adequate fit to the Rasch model, except for the item surface area. Person reliability of the Observer Scale and Patient Scale was 0.82 and 0.77, respectively. Dimensionality analysis revealed that the unexplained variance by the first contrast of both scales was 1.7 units. Spearman correlation between the Observer Scale Rasch measure and the overall opinion of the clinician was 0.75. The Rasch model demonstrated that the POSAS is a reliable and valid scale that measures the single-construct scar qualit

Supplement: "Localization and broadband follow-up of the gravitational-wave transient GW150914" (2016, ApJL, 826, L13)

This Supplement provides supporting material for Abbott et al. (2016a). We briefly summarize past electromagnetic (EM) follow-up efforts as well as the organization and policy of the current EM follow-up program. We compare the four probability sky maps produced for the gravitational-wave transient GW150914, and provide additional details of the EM follow-up observations that were performed in the different bands

Burns to the head and neck: epidemiology and predictors of surgery

BACKGROUND: The face is a frequent site of burn, but prevalence rates vary and reports are often limited to one healthcare setting. We examined the incidence of facial burns in the Netherlands in Emergency Departments (ED), hospitals and burn centres. Additionally, we identified which patient, injury and burn-related characteristics were predictors of facial burns, facial surgery and facial reconstruction in burn centres. METHODS: A retrospective, observational study was conducted including data from the Dutch Injury Surveillance System, the National Hospital Discharge Register and burn centres in a 5-year period (2003-2007). RESULTS: Facial burn incidences per 100,000 were 15.1 for ED visits, 1.3 for hospital admissions and 1.4 for burn centre admissions. A total of 2691 patients were admitted to Dutch burn centres; 47.5% (n=1277) had facial burns of which 20.5% received primary facial surgery and 5.3% received facial reconstruction in follow-up. Predictors of facial burns and facial surgery were identified. Predictors of facial reconstructive surgery were burns to the neck (ventral), fire/flame burns and number of facial surgeries in the acute phase of the burn. CONCLUSIONS: One in five patients with facial burns admitted to a Dutch burn centre received primary facial surgery and 1 in 20 received facial reconstructive surgery within a follow-up of minimum 2 years

Burns to the head and neck:epidemiology and predictors of surgery

BACKGROUND: The face is a frequent site of burn, but prevalence rates vary and reports are often limited to one healthcare setting. We examined the incidence of facial burns in the Netherlands in Emergency Departments (ED), hospitals and burn centres. Additionally, we identified which patient, injury and burn-related characteristics were predictors of facial burns, facial surgery and facial reconstruction in burn centres. METHODS: A retrospective, observational study was conducted including data from the Dutch Injury Surveillance System, the National Hospital Discharge Register and burn centres in a 5-year period (2003-2007). RESULTS: Facial burn incidences per 100,000 were 15.1 for ED visits, 1.3 for hospital admissions and 1.4 for burn centre admissions. A total of 2691 patients were admitted to Dutch burn centres; 47.5% (n=1277) had facial burns of which 20.5% received primary facial surgery and 5.3% received facial reconstruction in follow-up. Predictors of facial burns and facial surgery were identified. Predictors of facial reconstructive surgery were burns to the neck (ventral), fire/flame burns and number of facial surgeries in the acute phase of the burn. CONCLUSIONS: One in five patients with facial burns admitted to a Dutch burn centre received primary facial surgery and 1 in 20 received facial reconstructive surgery within a follow-up of minimum 2 years

An objective device for measuring surface roughness of skin and scars

Scar formation remains a major clinical problem; therefore, various therapies have been developed to improve scar quality. To evaluate the effectiveness of these therapies, objective measurement tools are necessary. An appropriate, objective measuring instrument for assessment of surface roughness is not yet available in a clinical setting. The Phaseshift Rapid In Vivo Measurement of the Skin (PRIMOS) (GFMesstechnik GmbH, Teltow, Germany) could be such an instrument. This device noninvasively produces a 3-dimensional image of the skin microtopography and measures surface roughness. The aim of this study was to investigate the reliability and validity of the PRIMOS for objective and quantitative measurement of surface roughness of skin and scars. Three observers assessed skin and burn scars in 60 patients using the PRIMOS and a subjective scale, the Patient and Observer Scar Assessment Scale. Reliability was tested using the intraclass correlation of intraobserver and interobserver measurements. An intraclass correlation coefficient of 0.7 or greater was required for reliable results. To test validity, scores of the PRIMOS were compared with scores of the subjective scale (Pearson correlation). A Pearson correlation coefficient greater than 0.6 was considered a strong positive correlation. All 3 surface roughness parameters of the PRIMOS showed good intraobserver and interobserver reliability for skin and scars (intraclass correlation coefficient arithmetic mean of surface roughness > 0.85, mean of 5 highest peaks and 5 deepest valleys from entire measuring field > 0.88, peak count > 0.86). The parameter arithmetic mean of surface roughness showed a strong correlation with the subjective score (Pearson arithmetic mean of surface roughness 0.70; mean of 5 highest peaks and 5 deepest valleys from entire measuring field 0.53; peak count 0.54). The reliability and validity of the PRIMOS were only tested on skin and burn scars, not in other dermatologic diseases. The PRIMOS is a valid and reliable tool for objective noninvasive evaluation of surface roughness of both skin and burn scar

Potential cellular and molecular causes of hypertrophic scar formation

A scar is an expected result of wound healing. However, in some individuals, and particularly in burn victims, the wound healing processes may lead to a fibrotic hypertrophic scar, which is raised, red, inflexible and responsible for serious functional and cosmetic problems. It seems that a wide array of subsequent processes are involved in hypertrophic scar formation, like an affected haemostasis, exaggerated inflammation, prolonged reepithelialization, overabundant extracellular matrix production, augmented neovascularization, atypical extracellular matrix remodeling and reduced apoptosis. Platelets, macrophages, T-lymphocytes, mast cells, Langerhans cells and keratinocytes are directly and indirectly involved in the activation of fibroblasts, which in turn produce excess extracellular matrix. Following the chronology of normal wound healing, we unravel, clarify and reorganize the complex molecular and cellular key processes that may be responsible for hypertrophic scars. It remains unclear whether these processes are a cause or a consequence of unusual scar tissue formation, but raising evidence exists that immunological responses early following wounding play an important role. Therefore, when developing preventive treatment modalities, one should aim to put the early affected wound healing processes back on track as quickly as possibl

Clinical effectiveness of dermal substitution in burns by topical negative pressure:a multicenter randomized controlled trial

Previous research has shown clinical effectiveness of dermal substitution; however, in burn wounds, only limited effect has been shown. A problem in burn wounds is the reduced take of the autograft, when the substitute and graft are applied in one procedure. Recently, application of topical negative pressure (TNP) was shown to improve graft take. The aim of this study was to investigate if application of a dermal substitute in combination with TNP improves scar quality after burns. In a four-armed multicenter randomized controlled trial, a split-skin graft with or without a dermal substitute and with or without TNP was compared in patients with deep dermal or full-thickness burns requiring skin transplantation. Graft take and rate of wound epithelialization were evaluated. Three and 12 months postoperatively, scar parameters were measured. The results of 86 patients showed that graft take and epithelialization did not reveal significant differences. Significantly fewer wounds in the TNP group showed postoperative contamination, compared to other groups. Highest elasticity was measured in scars treated with the substitute and TNP, which was significantly better compared to scars treated with the substitute alone. Concluding, this randomized controlled trial shows the effectiveness of dermal substitution combined with TNP in burns, based on extensive wound and scar measurements

Clinical effectiveness of dermal substitution in burns by topical negative pressure: a multicenter randomized controlled trial

Previous research has shown clinical effectiveness of dermal substitution; however, in burn wounds, only limited effect has been shown. A problem in burn wounds is the reduced take of the autograft, when the substitute and graft are applied in one procedure. Recently, application of topical negative pressure (TNP) was shown to improve graft take. The aim of this study was to investigate if application of a dermal substitute in combination with TNP improves scar quality after burns. In a four-armed multicenter randomized controlled trial, a split-skin graft with or without a dermal substitute and with or without TNP was compared in patients with deep dermal or full-thickness burns requiring skin transplantation. Graft take and rate of wound epithelialization were evaluated. Three and 12 months postoperatively, scar parameters were measured. The results of 86 patients showed that graft take and epithelialization did not reveal significant differences. Significantly fewer wounds in the TNP group showed postoperative contamination, compared to other groups. Highest elasticity was measured in scars treated with the substitute and TNP, which was significantly better compared to scars treated with the substitute alone. Concluding, this randomized controlled trial shows the effectiveness of dermal substitution combined with TNP in burns, based on extensive wound and scar measurements