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The contribution of joint and skin improvements to the health-related quality of life of patients with psoriatic arthritis: a post hoc analysis of two randomised controlled studies
  1. Arthur Kavanaugh1,
  2. Alice Gottlieb2,
  3. Akimichi Morita3,
  4. Joseph F Merola4,5,
  5. Chen-Yen Lin6,
  6. Julie Birt6,
  7. Catherine L Shuler6,
  8. Matthew M Hufford6,
  9. Diamant Thaçi7
  1. 1Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, California, USA
  2. 2Department of Dermatology, Icahn School of Medicine at Mt. Sinai, New York, New York, USA
  3. 3Department of Geriatric and Environmental Dermatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
  4. 4Department of Medicine, Division of Rheumatology, and Department of Dermatology, Harvard Medical School, Boston, Massachusetts, USA
  5. 5Department of Medicine, Division of Rheumatology, and Department of Dermatology, Brigham and Women's Hospital, Boston, Massachusetts, USA
  6. 6Lilly Research Labs, Eli Lilly and Company, Indianapolis, Indiana, USA
  7. 7Comprehensive Center of Inflammation Medicine, University Hospital Schleswig-Holstein Campus, Luebeck, Germany
  1. Correspondence to Professor Arthur Kavanaugh, University of California, San Diego, La Jolla, USA; akavanaugh{at}


Objective Determine the contribution of joint and skin improvements to health-related quality of life (HRQoL) in patients with psoriatic arthritis (PsA).

Methods SPIRIT-P1 and SPIRIT-P2 are phase 3 trials investigating ixekizumab, an interleukin-17A antagonist, in the treatment of patients with active PsA. Patients were randomised to ixekizumab or placebo. Outcomes included the Disease Activity Index for Psoriatic Arthritis (DAPSA), the Psoriasis Area and Severity Index (PASI), the European Quality of Life-Five Dimensions (EQ-5D) Visual Analogue Score (VAS), the 36-Item Short-Form Health Survey (SF-36) and the Work Productivity and Activity Impairment (WPAI) Questionnaire. The contribution of joint and skin improvements to HRQoL was modelled using a smoothing spline method and depicted with response surface graphics.

Results In this integrated analysis, 402 patients with PsA had baseline psoriasis of ≥3% of body surface area. We applied response surface modelling to this patient data set to investigate the relationship between DAPSA, PASI and HRQoL improvements at week 24. The greatest improvement in EQ-5D VAS was associated with the largest per cent improvements in both DAPSA and PASI together, rather than DAPSA or PASI alone. Similar observations were made in domains of SF-36 and WPAI.

Conclusion Optimal improvements in patients’ HRQoL were dependent on successful treatment of both joint and skin symptoms.

  • psoriatic arthritis
  • psoriasis
  • treatment
  • health-related quality of life

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  • Handling editor Josef S Smolen

  • Presented at Some of these results were previously presented as a poster presentation at the 2017 Annual Meeting of the American College of Rheumatology.

  • Contributors AK contributed to the acquisition of data and the analysis and interpretation of the study results. AG and CYL contributed to the conception of the work and the analysis and interpretation of the study results. AM and JFM contributed to the analysis and interpretation of the study results. JB contributed to the design of the study and the interpretation of study results. CLS contributed to the acquisition and interpretation of the study results. MMH contributed to the conception of the work, the design of the study, and the analysis and interpretation of the study results. DT contributed to the acquisition, analysis and interpretation of the study results. All authors contributed to the critical revisions and approved the final version of the manuscript.

  • Funding This project was supported by Eli Lilly and Company.

  • Competing interests AK has been a consultant for Eli Lilly and Company. AG has received consulting or advisory board honoraria, speaking honoraria and/or grants from Abbvie, BMS, Celgene Corporation, Dermira, Eli Lilly and Company, Incyte Corporation, Janssen Biotech, Janssen-Ortho, LEO Pharma, US, Lilly ICOS LLC, Novartis, Sun Pharmaceuticals and UCB. AM has received grant support and lecture fees from AbbVie, Esai, Kyowa Hakko Kirin, Leo Pharma, Maruho, Mitsubishi Tanabe Pharma, Novartis and Torii Pharmaceutical and lecture fees from Celgene, Eli Lilly Japan and Janssen Pharmaceutical. JFM has received consulting fees, speaking fees and/or honoraria from AbbVie, Eli Lilly, Novartis, Pfizer, UCB, Celgene, Sanofi, Regeneron, Merck, Biogen Idec and Janssen, and has served as a paid consultant for investment analysis companies Cowen Group and GLG. CYL, JB and MMH are full-time employees and shareholders of Eli Lilly and Company. CLS is a former employee and shareholder of Eli Lilly and Company. DT has been a consultant and advisor and has received speaking fees and grants, and served as an investigator in clinical trials for the following companies: AbbVie, Almirall, Amgen, Biogen Idec, BMS, Boehringer Ingelheim, Celgene, Dignity, Dermavant, Eli Lilly, Galapagos, GSK, Galderma, LEO Pharma, Janssen-Cilag, MSD, Novartis, Pfizer and Regeneron.

  • Patient and public involvement statement This research was done without patient involvement. Patients were not invited to comment on the study design and were not consulted to develop patient relevant outcomes or to interpret the results. Patients were not invited to contribute to the writing or editing of this document for readability or accuracy.

  • Patient consent for publication Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Lilly provides access to all individual participant data collected during the trial, after anonymisation, with the exception of pharmacokinetic or genetic data. Data are available to request 6 months after the indication studied has been approved in the USA and EU and after primary publication acceptance, whichever is later. No expiration date of data requests is currently set once they are made available. Access is provided after a proposal has been approved by an independent review committee identified for this purpose and after receipt of a signed data sharing agreement. Data and documents, including the study protocol, statistical analysis plan, clinical study report and blank or annotated case report forms, will be provided in a secure data sharing environment for up to 2 years per proposal. For details on submitting a request, see the instructions provided at

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