The Science Behind GRIDD

The GRIDD project has developed a new methodology and a novel patient-impact measurement tool through a multi-phased development process that relied on engaging dermatology patients and their dermatology organizations worldwide. 

The GRIDD research gatheres patients’ views on the impact of their disease and is the first global research project from the patient perspective encompassing all dermatological conditions. 

Below is a summary of the scientific approach that guides the project. 

GRIP – Methodology 

GRIP: Global Research of Impacts on Patients - represents the research methodology developed with the GRIDD researchers from Cardiff and Hamburg Universities developed that guides the project through its phases.  

One of the key outcomes of this methodology will be a new patient impact measurement tool. 

PRIDD - Patient-Impact Measurement Tool 

PRIDDPatient-Reported Impact of Dermatological Diseases - the world’s first dermatology patient-impact measurement tool (or questionnaire) that will meet the COSMIN Standard A for scientific measures.

When PRIDD launches globally, the data generated from the millions of respondents will contribute to GRIDD open-source global dataset. 

This data will then be leveraged for multiple purposes from publications, research, education, fundraising, and advocacy.  The PRIDD tool is also of great interest to government decision-makers as they evaluate treatment and care options.  

GlobalSkin will advocate for the global dermatology community to adopt PRIDD as the best, validated measurement tool that will address shortcomings of the DLQI (Dermatology Life Quality Index).

We also will advocate for PRIDD to be used in clinical trials and its data leveraged to build the case for raising dermatology higher in the global disease rankings such as the DALY (Disability Adjusted Life Years).    

Statistical Analyses 

A Statistical Analysis Plan was designed based on specific research questions. The research fellow conducting the analyses will be supported by the statistical expert group of the CVDerm/IVDP Institute at the University Medical Center of Hamburg. If needed, additional expertise will be invited to provide their views into the Plan.

Data Set

Most data will be collected through dermatology patient organizations and networks via electronic data capturing. All data from these sources will be captured and available for analysis. GlobalSkin will retain the rights to the data - PRIDD and the GRIP methodology.

During the development of the electronic versions of the PRIDD tool, further patient data on their needs and validity of the overall GRIDD project will be gained. During the GRIDD research phases this data will be temporarily stored in the development center at the CVDerm at the University of Hamburg.


Standard variables are being used according to the CVDerm’s sanctioned approach for all existing German databases (note that these German database variables fall into standard accepted variables for similar studies globally): 

  • Baseline variables: Age, gender, duration of disease, comorbidities  
  • Minimum outcomes variables (used to compare with PRIDD): PASI, BSA, DLQI, PBI (at baseline – 3 – 6 months) 
  • Patient benefit  
  • Patient benefit questionnaire  
  • Electronic Patient Benefit Index (PBI)  
  • Data on feasibility and acceptance of an electronic version  

Researcher Bias

The GRIP methodology is designed to address researcher bias at several points in the research including the Phase 3 Delphi.

The Delphi two-survey approach analyzed the first survey results for biases and then reconfirmed the impact statements are truly patient-derived with the second survey. The Delphi findings resulted in a more accurate and robust data set that fed into the development of PRIDD.  Now in  Phase 4, which involves psychometric testing before its patient impact statements are finalized.