Investigator and Patient Global Assessment Measures for Psoriasis Clinical Trials: A Systematic Review on Measurement Properties from the International Dermatology Outcome Measures (IDEOM) Initiative

  • Lourdes M. Perez-Chada
  • Nicole F. Salame
  • Adam R. Ford
  • Kristina Callis Duffin
  • Amit Garg
  • Alice B. Gottlieb
  • John Latella
  • Joseph F. Merola
  • April W. ArmstrongEmail author
Systematic Review


Background and Objective

The International Dermatology Outcome Measures (IDEOM) has defined a core set of domains to be measured in all psoriasis clinical trials. This set comprises the following domains: skin manifestations, psoriasis and psoriatic arthritis symptoms, health-related quality of life, investigator global, patient global, and treatment satisfaction. The next step is to define how to measure these domains. The objective of this article was to evaluate the quality of available instruments to assess ‘investigator global’ and ‘patient global’ domains to identify the most appropriate instruments.


Reviewers conducted a systematic literature review to retrieve studies on the measurement properties of instruments including either an investigator global assessment or a patient global assessment. Following the COnsensus based standards for the Selection of health Measurement INstruments (COSMIN) checklist, three independent reviewers rated the quality of each study. We then performed a qualitative synthesis of the evidence.


We identified nine investigator global assessments and three patient global assessments, reflecting substantial variability in global assessment instruments. Overall, most measures lacked evidence for content validity and feasibility. The Lattice System-Physician Global Assessment, Product of the Investigator Global Assessment and Body Surface Area, and the professional-Simplified Psoriasis Index had higher levels of evidence for validity, reliability, and/or responsiveness than the 5- and 6-point investigator global assessments. The self-assessment-Simplified Psoriasis Index was the only patient global assessment with evidence for validity, reliability, and responsiveness.


The 5- and 6-point investigator global assessments, which are the most widely used investigator global assessments in registered clinical trials, have less evidence for measurement properties as compared with the Lattice System-Physician Global Assessment, professional-Simplified Psoriasis Index, and the Product of the Investigator Global Assessment and Body Surface Area. However, all instruments lack evidence for content validity and feasibility. Further validation studies of investigator global assessments and patient global assessments are required to recommend the best global measure for psoriasis clinical trials.


Compliance with Ethical Standards


International Dermatology Outcome Measures (IDEOM) funded the conduct of this study.

Conflict of interest

Dr. Garg is a consultant/advisor for Abbvie, Pfizer, UCB, and Asana Biosciences and received a grant from UCB. Dr. Gottlieb is an advisor/consultant for Janssen Inc., Celgene, Beiersdorf, BMS, Abbvie, UCB, Novartis, Incyte Corporation, Lilly, Reddy Labs, Valeant, Dermira, Allergan, Sun Pharmaceutical Industries, XBiotech, Leo, Avotres Therapeutics, and Boeringer Ingelheim. She received research/educational grants from Janssen, Incyte Corporation, XBiotech, Novartis, Boeringer Ingelheim, and UCB. In addition, she participated in the development of the National Psoriasis Foundation Psoriasis Score, an instrument discussed in the present study. John Latella is an advisor for Boehringer Ingelheim and Glaxo Smith Kline. Dr. Duffin serves as an advisory board/consultant/investigator for Amgen, Abbvie, Celgene, Novartis, Lilly, Pfizer, Stifle, Janssen, Ortho Dermatologic, and Boehringer Ingelheim. In addition, she has participated in validation studies of the IGA×BSA, an instrument discussed in the present study. Dr. Merola has served as a consultant/investigator/advisory board for Merck, AbbVie Eli Lilly, Incyte, Janssen, UCB, Almirall, Pfizer, Sun Pharma, Novartis, and Burrage Capital Mgmt. In addition, he received grants from Aclaris, Novartis, Leo, Celgene, and Dermavent. Dr. Armstrong serves as a consultant/advisor/investigator for Leo Pharma, Novartis, Delmira, UCB, Abbvie, Janssen, Eli Lilly, Regeneron and Sanofi, Science 37, Modernizing Medicine, Merck, Parexel, Celgene, Ortho Dermatologics, and Pfizer. Drs. Perez-Chada, Salame, and Ford have no conflicts of interest that are directly relevant to the content of this article.

Supplementary material

40257_2019_496_MOESM1_ESM.pdf (632 kb)
Supplementary file1 (PDF 632 kb)


  1. 1.
    Williamson PR, Altman DG, Bagley H, Barnes KL, Blazeby JM, Brookes ST et al. The COMET Handbook: version 1.0. Trials. 2017;18(Suppl 3):280. 10.1186/s13063-017-1978-4.Google Scholar
  2. 2.
    Gottlieb AB, Levin AA, Armstrong AW, Abernethy A, Duffin KC, Bhushan R, et al. The International Dermatology Outcome Measures Group: formation of patient-centered outcome measures in dermatology. J Am Acad Dermatol. 2015;72(2):345–8. Scholar
  3. 3.
    Boers M, Brooks P, Strand CV, Tugwell P. The OMERACT filter for outcome measures in rheumatology. J Rheumatol. 1998;25(2):198–9.PubMedGoogle Scholar
  4. 4.
    Callis Duffin K, Merola JF, Christensen R, Latella J, Garg A, Gottlieb AB, et al. Identifying a core domain set to assess psoriasis in clinical trials. JAMA Dermatol. 2018. Scholar
  5. 5.
    Prinsen CA, Vohra S, Rose MR, Boers M, Tugwell P, Clarke M, et al. How to select outcome measurement instruments for outcomes included in a “Core Outcome Set”—a practical guideline. Trials. 2016;17(1):449.CrossRefGoogle Scholar
  6. 6.
    Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JP, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. PLoS Med. 2009;6(7):e1000100.CrossRefGoogle Scholar
  7. 7.
    Langley RG, Feldman SR, Nyirady J, van de Kerkhof P, Papavassilis C. The 5-point Investigator's Global Assessment (IGA) Scale: A modified tool for evaluating plaque psoriasis severity in clinical trials. J Dermatol Treat. 2015;26(1):23–31. Scholar
  8. 8.
    Duffin KC, Papp KA, Bagel J, Levi E, Chen R, Gottlieb AB. Evaluation of the physician global assessment and body surface area composite tool for assessing psoriasis response to apremilast therapy: results from ESTEEM 1 and ESTEEM 2. JDD. 2017;16(2):147–53.PubMedGoogle Scholar
  9. 9.
    Langley RG, Ellis CN. Evaluating psoriasis with psoriasis area and severity index, psoriasis global assessment, and lattice system physician's global assessment. J Am Acad Dermatol. 2004;51(4):563–9. Scholar
  10. 10.
    Nikiphorou E, Radner H, Chatzidionysiou K, Desthieux C, Zabalan C, van Eijk-Hustings Y, et al. Patient global assessment in measuring disease activity in rheumatoid arthritis: a review of the literature. Arthritis Res Ther. 2016;18(1):251. Scholar
  11. 11.
    Talli S, Etcheto A, Fautrel B, Balanescu A, Braun J, Canete JD, et al. Patient global assessment in psoriatic arthritis—what does it mean? An analysis of 223 patients from the Psoriatic arthritis impact of disease (PsAID) study. Joint Bone Spine Revue du rhumatisme. 2016;83(3):335–40. Scholar
  12. 12.
    Mokkink LB, Terwee CB, Knol DL, Stratford PW, Alonso J, Patrick DL, et al. The COSMIN checklist for evaluating the methodological quality of studies on measurement properties: a clarification of its content. BMC Med Res Methodol. 2010;10:22. Scholar
  13. 13.
    Terwee CB, Mokkink LB, Knol DL, Ostelo RW, Bouter LM, de Vet HC. Rating the methodological quality in systematic reviews of studies on measurement properties: a scoring system for the COSMIN checklist. Qual Life Res. 2012;21(4):651–7. Scholar
  14. 14.
    Terwee CB, Bot SD, de Boer MR, van der Windt DA, Knol DL, Dekker J, et al. Quality criteria were proposed for measurement properties of health status questionnaires. J Clin Epidemiol. 2007;60:34–42.CrossRefGoogle Scholar
  15. 15.
    Furlan AD, Pennick V, Bombardier C, van Tulder M. 2009 updated method guidelines for systematic reviews in the Cochrane Back Review Group. Spine. 2009;34(18):1929–41. Scholar
  16. 16.
    Fayers PM, Hand DJ, Bjordal K, Groenvold M. Causal indicators in quality of life research. Qual Life Res. 1997 Sep 1;6(5):393–406.CrossRefGoogle Scholar
  17. 17.
    Prinsen CA, Mokkink LB, Bouter LM, Alonso J, Patrick DL, De Vet HC, Terwee CB. COSMIN guideline for systematic reviews of patient-reported outcome measures. Qual Life Res. 2018 May 1;27(5):1147–57.CrossRefGoogle Scholar
  18. 18.
    Berth-Jones J, Grotzinger K, Rainville C, Pham B, Huang J, Daly S, et al. A study examining inter- and intrarater reliability of three scales for measuring severity of psoriasis: Psoriasis Area and Severity Index, Physician's Global Assessment and Lattice System Physician's Global Assessment. Br J Dermatol. 2006;155(4):707–13. Scholar
  19. 19.
    Simpson MJ, Chow C, Morgenstern H, Luger TA, Ellis CN. Comparison of three methods for measuring psoriasis severity in clinical studies (Part 2 of 2): use of quality of life to assess construct validity of the Lattice System Physician's Global Assessment, Psoriasis Area and Severity Index and Static Physician's Global Assessment. JEADV. 2015;29(7):1415–20. Scholar
  20. 20.
    Chow C, Simpson MJ, Luger TA, Chubb H, Ellis CN. Comparison of three methods for measuring psoriasis severity in clinical studies (Part 1 of 2): change during therapy in Psoriasis Area and Severity Index, Static Physician's Global Assessment and Lattice System Physician's Global Assessment. JEADV. 2015;29(7):1406–14. Scholar
  21. 21.
    Walsh JA, McFadden M, Woodcock J, Clegg DO, Helliwell P, Dommasch E, et al. Product of the Physician Global Assessment and body surface area: a simple static measure of psoriasis severity in a longitudinal cohort. J Am Acad Dermatol. 2013;69(6):931–7. Scholar
  22. 22.
    Merola JF, Amato DA, See K, Burge R, Mallinckrodt C, Ojeh CK, et al. Evaluation of sPGA x BSA as an outcome measure and treatment target for clinical practice. J Invest Dermatol. 2018. Scholar
  23. 23.
    Chularojanamontri L, Griffiths CE, Chalmers RJ. The Simplified Psoriasis Index (SPI): a practical tool for assessing psoriasis. J Invest Dermatol. 2013;133(8):1956–62. Scholar
  24. 24.
    Meah N, Alsharqi A, Azurdia RM, Owens LC, Parslew R, Chularojanamontri L. Assessing the validity and response distribution of the simplified psoriasis index in patients receiving phototherapy. Aust J Dermatol. 2018;59(1):41–7. Scholar
  25. 25.
    Chularojanamontri L, Griffiths CEM, Chalmers RJG. Responsiveness to change and interpretability of the simplified psoriasis index. J Invest Dermatol. 2014;134(2):351–8. Scholar
  26. 26.
    Cappelleri JC, Bushmakin AG, Harness J, Mamolo C. Psychometric validation of the physician global assessment scale for assessing severity of psoriasis disease activity. Qual Life Res. 2013;22(9):2489–99. Scholar
  27. 27.
    Cohen AD, Van-Dijk D, Naggan L, Vardy DA. Factor analysis of the Beer Sheva Psoriasis Severity Score (BPSS). IMAJ. 2008;10(6):419–23.PubMedGoogle Scholar
  28. 28.
    Cohen AD, Van-Dijk D, Naggan L, Vardy DA. Effectiveness of climatotherapy at the Dead Sea for psoriasis vulgaris: a community-oriented study introducing the 'Beer Sheva Psoriasis Severity Score'. J Dermatol Treat. 2005;16(5–6):308–13. Scholar
  29. 29.
    Gottlieb AB, Chaudhari U, Baker DG, Perate M, Dooley LT. The National Psoriasis Foundation Psoriasis Score (NPF-PS) system versus the Psoriasis Area Severity Index (PASI) and Physician's Global Assessment (PGA): a comparison. JDD. 2003;2(3):260–6.PubMedGoogle Scholar
  30. 30.
    Faust HB, Gonin R, Chuang TY, Lewis CW, Melfi CA, Farmer ER. Reliability testing of the dermatology index of disease severity (DIDS). An index for staging the severity of cutaneous inflammatory disease. Arch Dermatol. 1997;133(11):1443–8.CrossRefGoogle Scholar
  31. 31.
    Patrick DL, Burke LB, Powers JH, Scott JA, Rock EP, Dawisha S, et al. Patient-reported outcomes to support medical product labeling claims: FDA perspective. Value Health. 2007;10(Suppl 2):S125–S137137. Scholar
  32. 32.
    Tugwell P, Boers M, D’Agostino M-A, Beaton D, Boonen A, Bingham CO et al. Updating the OMERACT filter: implications of filter 2.0 to select outcome instruments through assessment of “truth”: content, face, and construct validity. J Rheumatol. 2014:jrheum. 131310.Google Scholar
  33. 33.
    Callis Duffin K, Gottlieb AB. Outcome measures for psoriasis severity: a report from the GRAPPA 2012 annual meeting. J Rheumatol. 2013;40(8):1423–4. Scholar
  34. 34.
    Robinson A, Kardos M, Kimball AB. Physician Global Assessment (PGA) and Psoriasis Area and Severity Index (PASI): why do both? A systematic analysis of randomized controlled trials of biologic agents for moderate to severe plaque psoriasis. J Am Acad Dermatol. 2012;66(3):369–75. Scholar
  35. 35.
    Spuls PI, Lecluse LL, Poulsen ML, Bos JD, Stern RS, Nijsten T. How good are clinical severity and outcome measures for psoriasis?: quantitative evaluation in a systematic review. J Investig Dermatol. 2010 Apr 1;130(4):933–43.CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2020

Authors and Affiliations

  • Lourdes M. Perez-Chada
    • 1
  • Nicole F. Salame
    • 2
  • Adam R. Ford
    • 3
  • Kristina Callis Duffin
    • 4
  • Amit Garg
    • 5
  • Alice B. Gottlieb
    • 6
  • John Latella
    • 7
  • Joseph F. Merola
    • 1
    • 8
  • April W. Armstrong
    • 9
    Email author
  1. 1.Department of DermatologyBrigham and Women’s HospitalBostonUSA
  2. 2.Irvine School of MedicineUniversity of CaliforniaIrvineUSA
  3. 3.Keck School of Medicine of the University of Southern CaliforniaLos AngelesUSA
  4. 4.Department of DermatologyUniversity of UtahSalt Lake CityUSA
  5. 5.Department of DermatologyHofstra Northwell School of MedicineNew Hyde ParkUSA
  6. 6.Department of DermatologyIcahn School of Medicine at Mount SinaiNew YorkUSA
  7. 7.International Dermatology Outcome Measures (IDEOM)WindsorUSA
  8. 8.Department of Medicine, Division of RheumatologyBrigham and Women’s HospitalBostonUSA
  9. 9.Department of DermatologyKeck School of Medicine of the University of Southern CaliforniaLos AngelesUSA

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