Evaluating scar quality

The POSAS measures scar quality in all types of scars by evaluating visual (e.g. color), tactile (e.g. pliability) and sensory (e.g. itch) characteristics of the scar from the perspective of the observer and patients.

The first version of the POSAS has been introduced in 2004. A year later, after some minor adjustments, the second version followed. This version is available in 25 languages. Currently, the third version of the POSAS has been developed by gaining input from international scar experts (i.e. patients as well as professionals) on its content. The POSAS 3.0 is launched at EBA 2022 and available in 10 languages with many more to come.

For research and clinical use

The POSAS can be used in both clinical and research settings in order to measure the effectiveness of scar treatments, monitor scar maturation over time, and identify the need for future treatments.

From the perspective of observers and patients

Sensory characteristics can only be accurately reported by the patient, so the Observer Scale only contains those characteristics that concern the visual and tactile characteristics of the scar. Consequently, the Patient Scale contains items concerning the visual, tactile and sensory characteristics of the scar.


The POSAS 2.0 and 3.0 are available in the following languages:

  • Armenian (2.0)
  • Bulgarian (2.0)
  • Chinese (2.0&3.0)
  • Czech (2.0)
  • Dutch (2.0&3.0)
  • English (2.0&3.0)
  • Filipino (2.0)
  • French (2.0)
  • German (2.0)
  • Greek (3.0)
  • Hebrew (2.0)
  • Hindi (2.0)
  • Indonesian (3.0)
  • Italian (2.0)
  • Japanese (2.0&3.0)
  • Korean (2.0)
  • Latin American Spanish (3.0)
  • Marathi (2.0)
  • Norwegian (2.0)
  • Polish (2.0)
  • Portuguese Brazilian (2.0&3.0)
  • Portuguese European (3.0)
  • Romanian (2.0)
  • Russian (3.0)
  • Slovak (2.0)
  • Spanish (2.0)
  • Swedish (2.0)
  • Tamil (2.0)
  • Thai (2.0)

Most of these versions have been translated by official translation offices. However, some have been translated by researchers themselves. If you are interested in translating the POSAS into your language, please contact us for permission.

Development of the POSAS 3.0

In 2017, we started the development of the POSAS 3.0. The main reasons for initiating this project was the lack of input by patients and international professionals in the development of the POSAS 2.0.

This third POSAS version is developed to measure scar quality in patients with all types of scars, including those caused by burns, necrotizing fasciitis, acne, trauma, or surgery.

Patient Scale

The Patient Scale has been developed using a series of focus group meetings that took place in the Netherlands and Australia. The objective of this focus group study was to explore the concepts of scar quality that patients living with scars consider to be most important. The concepts that were identified during the focus groups determined the contents of the draft for the Patient Scale. This draft was pilot tested on patients from the Netherlands, Australia and the UK. Based on the comments made by patients, the draft was further revised.

Observer Scale

The Observer Scale has been developed using a systematic method to reach consensus among experts, otherwise known as a Delphi study. The POSAS 3.0 Delphi study has used three different rounds of anonymous, online questionnaires in order to obtain expert opinion on the content of the Observer Scale within the POSAS 3.0.

POSAS 3.0 is available now!

A reliable and valid measurement scale

The POSAS, with high quality reliability but indeterminate validity, was considered to be superior in performance based on existing evidence.

from: A systematic review of the quality of burn scar rating scales for clinical and research use. Z. Tyack. Burns. 2012

The introduction of the Patient and Observer Scar Assessment Scale (POSAS) in 2004 was a turning point in the assessment of scars through the use of scales. The POSAS was the first scale to take into account both the patient and provider perspective.

from: A review of scar assessment scales, Tuyet A Nguyen et al. Seminars in Cutaneous Medicine and Surgery, Vol. 34, March 2015

To date, many authors consider the POSAS most suitable for scar assessment as it includes a comprehensive list of frequently used scar features, incorporates a patients’ opinion, and has a superior internal consistency and reliability compared with the VSS..

from: a clinimetric overview of scar assessent scales, M.B.A. van der Wal et al. Journal of Burn Care and Research, ‎2012

The history of POSAS

“I am excited that we are now bringing together the expertise of patients and international professionals.”

‘Never create your own measurement instrument.’ That is what everyone told me at the end of the 1990s when I explored the possibility of developing a scale for assessing scars. At that time, I was halfway through my Ph.D project in which we compared the effectiveness of skin replacements in improving the quality of burn scars. Throughout this project, I was surprised by the scarcity of measuring instruments that I could use to measure the quality of scars. However, the pioneering work by Sullivan & Smith (1990) provided us with the tool that has become known as the Vancouver Scar Scale.

As is quite clear by now, I completely ignored the serious advice from the experts during my Ph.D. During the nineties, there was relatively little consideration for the opinion of patients regarding their experience, involvement and treatment outcome when seeking care. Thankfully, the world has changed! Today we acknowledge the importance of the patient opinion, which is noticeable in the development and implementation of various patient reported outcome measures. In the POSAS the patient’s opinion was included from the very beginning, as it combines the opinion of patients and observers regarding the quality of scars.

I am happy that I ignored the advice that had been giving to me regarding the development of the POSAS. I am also really proud of what we have achieved up until now. Futhermore, I am excited that we are now bringing together the expertise of patients and the input of many international professionals for the development of the POSAS version 3.0. I am looking forward to hearing about your experiences with it.

– Paul van Zuijlen, Founder of POSAS


Paul P.M. van Zuijlen
Paul P.M. van ZuijlenFounder of the POSAS, Professor and Plastic, Reconstructive and Burn Surgeon
Burn Center, Red Cross Hospital, Beverwijk, and Amsterdam UMC, location VUmc
Michelle E. Carrière
Michelle E. CarrièreMD, PhD candidate POSAS 3.0
Burn Center, Red Cross Hospital, Beverwijk, and Amsterdam UMC, location VUmc
Wieneke B. Mokkink
Wieneke B. MokkinkSenior Researcher in Clinimetrics
Department of Epidemiology and Biostatistics, Amsterdam UMC, location VUmc.
Riekie C.W. de Vet
Riekie C.W. de VetProfessor in Clinimetrics
Department of Epidemiology and Biostatistics, Amsterdam UMC, location VUmc.
Anouk Pijpe
Anouk PijpeEpidemiologist, Head Research Unit Burn Center Beverwijk
Burn Center, Red Cross Hospital Beverwijk and Amsterdam UMC, location VUmc
Adinda Mieras
Adinda MierasEpidemiologist and Senior Researcher
Burn Center, Red Cross Hospital Beverwijk and Amsterdam UMC, location VUmc
Frederique Kemme
Frederique KemmeMD, junior researcher
Burn Center, Red Cross Hospital Beverwijk and Amsterdam UMC, location VUmc
H. Ibrahim Korkmaz
H. Ibrahim KorkmazSenior Researcher in Burn Wound healing, Molecular Cell Biology and Skin regeneration
Amsterdam UMC, location VUmc
Françoise Loots
Françoise LootsBackoffice and financial coordinator POSAS 3.0
Dutch Burns Foundation, Beverwijk
Rob Baardse
Rob Baardse Executive Director
Dutch Burns Foundation, Beverwijk