Patient-reported and clinical outcomes

A cornerstone for people-centered healthcare research and clinical practice is the availability of reliable measurement instruments, mostly questionnaires. Patient-reported outcome (PRO) measures allow researchers and clinicians to ask patients, and in some cases their relatives, in a structured fashion about topics like how their disease affects different aspects of life, what they expect from treatment, or what effects a specific treatment has on them. Clinical outcome measures are tools for healthcare professionals, for example to determine the disease severity. These tools are critical in tailoring treatment to the individual.

Therefore, our research group contributes to the development, evaluation of psychometric properties1, and refinement of such patient-reported and clinical outcome measures. You can find an overview of our work in this field below.


1Psychometric properties of measurement tools include its validity (“Does the instrument actually measure what we think it does?”, “How well does it predict certain health outcomes?”) and reliability (“How consistent are the results over time or between two clinical assessors?”). We can only draw conclusions with certainty if we know the used instrument to be valid and reliable.

patient reported

Ongoing projects:

Background: The burden of dermatological diseases is systematically underestimated and there is little incentive for policymakers to address them as serious diseases. To overcome this disfavor, the International Alliance of Dermatology Patient Organizations (also known as GlobalSkin) launched the Global Research on the Impact of Dermatological Diseases (GRIDD) project, the first patient-initiated and -led impact research project in dermatology. This multi-year, multi-phase global research and advocacy project aims to develop and establish the routine use of a unique measure of the impact of dermatological diseases on patients’ lives – the Patient-Reported Impact of Dermatological Diseases (PRIDD) tool; and (2) to collect global data on the patients’ perspectives of disease burden in multiple skin diseases. These data will support local, national, and international advocacy work to prioritize dermatological conditions more accurately in the global health debate. 


Study Objectives:

  • Collect global data on the impact of dermatological conditions on patient’s lives using the PRIDD measure

  • Explore the relationship between disease burden and other relevant variables

  • Complete the psychometric testing and establish the minimal important change (MIC) of the original English PRIDD

  • Test the psychometric properties of the 16 cross-cultural translations of PRIDD


Study Design: Longitudinal study consisting of two online surveys administered approximately six weeks apart


Target Group: Adults (≥ 18 years) with a self-reported dermatological condition


Period: 2023 - 2024


Sponsor: The International Alliance of Dermatology Patient Organizations (GlobalSkin)

Background: Infants and toddlers represent an important population for juvenile dermatoses, yet this age group has not been in the focus of QoL research so far. In order to better understand the specific situation of affected children and their families, a skin-generic proxy quality of life questionnaire (InToDerm-QoL) was developed simultaneously in seven countries according to the methodology outlined by the European Academy of Dermatology and Venereology (EADV) Task Force on Quality of Life.


Study Objectives:

  • Psychometrically validate the German translation of the InToDerm-QoL questionnaire.

  • Assess quality of life in families with infants or children affected by a skin disease.


Study Design:

  • Cross-sectional

  • Non-interventional


Target Group: families of children aged 0 – 4 years with acute or chronic skin disease


Period: June 2021 – December 2022


Sponsor: Eli Lilly

Completed projects:

Background: People with chronic wounds perceive an impaired health-related quality of life (QoL). Physical impairments often include pain, itching, discomfort, involuntary physical inactivity, and exacerbation of other health problems. Additionally, feelings of frustration, anxiety, embarrassment, social isolation, depression and low self-esteem due to a negative self-concept affect social and emotional wellbeing. Besides, patients may experience distrust in healthcare professionals, and feel disheartened and frustrated about the treatment progress. In order to measure health-related quality of life in this patient group and address it in treatment, valid instruments are needed. Therefore, the Wound-QoL questionnaire was originally developed and psychometrically validated for use in Germany.


Study Objectives:

  • Psychometrically validate different language versions (German, U.S. English, Spanish) of the Wound-QoL questionnaire.

  • Test the cross-cultural structure and psychometric performance of the questionnaire.

  • Establish the minimal important difference (MID) of the Wound-QoL global score and its subscales.


Study Design:

  • Cross-sectional

  • Non-interventional


Target Groupadults with chronic wounds, relatives of patients 


Completed: 2021


Associated Publications:

  • Development and psychometric evaluation of the U.S. English Wound-QoL questionnaire to assess health-related quality of life in people with chronic wounds

  • Assessing the quality of life of people with chronic wounds by using the cross-culturally valid and revised Wound-QoL questionnaire

  • Determining the Minimal Important Difference for the Wound-QoL Questionnaire

  • Validation of the Spanish Wound-QoL Questionnaire

  • Differences between patient- and proxy-reported HRQoL using the Wound-QoL

  • The Wound-QoL questionnaire on quality of life in chronic wounds is highly reliable

Background: Xerosis cutis (dry skin) is a common but unspecific symptom of many skin diseases, causing discomfort or even a loss of quality of life for the patient. So far, no specific instruments for the quantification of xerosis beyond simple linear scales have been published.


Study Objectives:

  • Develop and validate a composite measuring instrument for the assessment of the extent (surface area affected) and severity of xerosis in clinical practice and research.


Study Design:

  • Literature review

  • Non-interventional

  • Exploratory


Target Group: persons with xerosis (n = 86) and without xerosis (n= 41)


Completed: 2021


Associated Publications:

Development and validation of an outcome instrument measuring dry skin - the Xerosis Area and Severity Index (XASI)