L Thorlacius1,2, A Garg3, P T Riis1, S M Nielsen2, V Bettoli4, J R Ingram5, V Del Marmol6, L Matusiak7, J C Pascual8, J Revuz9, K Sartorius10,11, T Tzellos12, H H van der Zee13, C C Zouboulis14, D M Saunte1, A B Gottlieb15, R Christensen2,16, G B E Jemec1. 1. Department of Dermatology, Zealand University Hospital, Roskilde/Health Sciences Faculty, University of Copenhagen, Copenhagen, Denmark. 2. Musculoskeletal Statistics Unit, The Parker Institute, Bispebjerg and Frederiksberg Hospital, The Capital Region of Denmark, Copenhagen, Denmark. 3. Department of Dermatology, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, U.S.A. 4. Dermatology and Venereology, University of Ferrara, Ferrara, Italy. 5. Department of Dermatology & Academic Wound Healing, Cardiff University, Cardiff, U.K. 6. Department of Dermatology, Hopital Erasme, Brussels, Université Libre de Bruxelles, Brussels, Belgium. 7. Department of Dermatology, Venereology and Allergology, Medical University, Wrocław, Poland. 8. Department of Dermatology, Hospital General Universitario de Alicante, Alicante, Spain. 9. 11 chaussée de la muette, 75016, Paris, France. 10. Department of Dermatology, Stockholm South General Hospital (Södersjukhuset), Stockholm, Sweden. 11. Department of Clinical Science and Education, Karolinska Institutet, Stockholm, Sweden. 12. Department of Dermatology, Faculty of Health Sciences, University Hospital of North Norway, Tromso, Norway. 13. Department of Dermatology, Erasmus University Medical Center, Rotterdam, the Netherlands. 14. Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Brandenburg Medical School Theodor Fontane, Dessau, Germany. 15. Department of Dermatology, ICahn School of Medicine at Mount Sinai, New York, NY, U.S.A. 16. Department of Rheumatology, Odense University Hospital, Odense, Denmark.
Abstract
BACKGROUND: Monitoring disease activity over time is a prerequisite for clinical practice and research. Valid and reliable outcome measurement instruments (OMIs) and staging systems provide researchers and clinicians with benchmark tools to assess the primary and secondary outcomes of interventional trials and to guide treatment selection properly. OBJECTIVES: To investigate inter-rater reliability and agreement in instruments currently used in hidradenitis suppurativa (HS), with dermatologists experienced in HS as the rater population of interest. METHODS: In a prospective completely balanced design, 24 patients with HS underwent a physical examination by 12 raters (288 assessments) using nine instruments. The results were analysed using generalized linear mixed models. RESULTS: For the staging systems, the study found good inter-rater reliability for Hurley staging in the axillae and gluteal region, moderate inter-rater reliability for Hurley staging in the groin and for Physician's Global Assessment, and fair inter-rater reliability for refined Hurley staging and the International HS Severity Scoring System. For all the tested OMIs, the observed intervals for limits of agreement were very wide relative to the ranges of the scales. CONCLUSIONS: The very wide intervals for limits of agreement imply that substantial changes are needed in clinical research in order to rule out measurement error. The results illustrate a difficulty, even for experienced HS experts, to agree on the type and number of lesions when evaluating disease severity. The apparent caveats call for global efforts, such as the HIdradenitis SuppuraTiva cORe outcomes set International Collaboration (HISTORIC) to reach consensus on how best to measure physical signs of HS reliably in randomized trials. What's already known about this topic? Without valid and reliable instruments to measure outcomes, researchers and clinicians lack the necessary benchmarks to assess primary and secondary end points of interventional trials properly. Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease. Several outcome measure instruments exist for HS, but their validation is generally incomplete or of relatively low methodological quality. What does this study add? Using a prospective completely balanced design this study examined inter-rater reliability with HS-experienced dermatologists as the rater population of interest. The study did not find very good reliability for any included instrument or lesion counts. This study illustrates the difficulty in finding agreement on the type and number of HS lesions, even among experts. The results question whether physical signs are best measured by a traditional physician lesion count instrument. What are the clinical implications of this work? For staging, Hurley staging and physician global visual analogue scale proved to be acceptable instruments in terms of inter-rater reliability. For the instruments designed to measure changes in health status, our study illustrates how difficult it is, even for experts, to measure the physical signs of HS using a simple rater counting. Consequently, other assessment methods of physicals signs, such as ultrasound evaluation, require consideration.
BACKGROUND: Monitoring disease activity over time is a prerequisite for clinical practice and research. Valid and reliable outcome measurement instruments (OMIs) and staging systems provide researchers and clinicians with benchmark tools to assess the primary and secondary outcomes of interventional trials and to guide treatment selection properly. OBJECTIVES: To investigate inter-rater reliability and agreement in instruments currently used in hidradenitis suppurativa (HS), with dermatologists experienced in HS as the rater population of interest. METHODS: In a prospective completely balanced design, 24 patients with HS underwent a physical examination by 12 raters (288 assessments) using nine instruments. The results were analysed using generalized linear mixed models. RESULTS: For the staging systems, the study found good inter-rater reliability for Hurley staging in the axillae and gluteal region, moderate inter-rater reliability for Hurley staging in the groin and for Physician's Global Assessment, and fair inter-rater reliability for refined Hurley staging and the International HS Severity Scoring System. For all the tested OMIs, the observed intervals for limits of agreement were very wide relative to the ranges of the scales. CONCLUSIONS: The very wide intervals for limits of agreement imply that substantial changes are needed in clinical research in order to rule out measurement error. The results illustrate a difficulty, even for experienced HS experts, to agree on the type and number of lesions when evaluating disease severity. The apparent caveats call for global efforts, such as the HIdradenitis SuppuraTiva cORe outcomes set International Collaboration (HISTORIC) to reach consensus on how best to measure physical signs of HS reliably in randomized trials. What's already known about this topic? Without valid and reliable instruments to measure outcomes, researchers and clinicians lack the necessary benchmarks to assess primary and secondary end points of interventional trials properly. Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease. Several outcome measure instruments exist for HS, but their validation is generally incomplete or of relatively low methodological quality. What does this study add? Using a prospective completely balanced design this study examined inter-rater reliability with HS-experienced dermatologists as the rater population of interest. The study did not find very good reliability for any included instrument or lesion counts. This study illustrates the difficulty in finding agreement on the type and number of HS lesions, even among experts. The results question whether physical signs are best measured by a traditional physician lesion count instrument. What are the clinical implications of this work? For staging, Hurley staging and physician global visual analogue scale proved to be acceptable instruments in terms of inter-rater reliability. For the instruments designed to measure changes in health status, our study illustrates how difficult it is, even for experts, to measure the physical signs of HS using a simple rater counting. Consequently, other assessment methods of physicals signs, such as ultrasound evaluation, require consideration.
Authors: N Goldfarb; J R Ingram; G B E Jemec; H B Naik; V Piguet; M J Hyde; R Freese; M A Lowes; A Alavi Journal: Br J Dermatol Date: 2019-09-17 Impact factor: 9.302
Authors: Rob L Shaver; Gregor B E Jemec; Rebecca Freese; Afsaneh Alavi; Michelle A Lowes; Noah Goldfarb Journal: Int J Dermatol Date: 2020-11-12 Impact factor: 3.204