Article Text

Incidence and time trends of joint surgery in patients with psoriatic arthritis: a register-based time series and cohort study from Denmark
  1. Jørgen Guldberg-Møller1,2,
  2. Rene Lindholm Cordtz3,
  3. Lars Erik Kristensen4,
  4. Lene Dreyer5,6
  1. 1 Copenhagen University Hospital, Bispebjerg and Frederiksberg, The Parker Institute, Frederiksberg, Denmark
  2. 2 Department of Rheumatology, Slagelse Sygehus, Slagelse, Denmark
  3. 3 Center for Rheumatology and Spine Diseases - Gentofte, Rigshospitalet, Hellerup, Denmark
  4. 4 Department of Rheumatology, The Parker Institute, Frederiksberg, Denmark
  5. 5 Department of Rheumatology, Aalborg University Hospital, Aalborg, Denmark
  6. 6 Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
  1. Correspondence to Dr Jørgen Guldberg-Møller, Copenhagen University Hospital, Bispebjerg and Frederiksberg, The Parker Institute, Frederiksberg 2000, Denmark; joergen.guldberg-moeller{at}


Objective To investigate time-trends and cumulative incidence of joint surgery among patients with psoriatic arthritis (PsA) compared with the general population.

Methods In this nationwide register-based cohort study, The Danish National Patient Registry was used to identify incident PsA patients. The 5-year incidence rates (IR) and incidence rate ratios (IRR) of joint surgery were calculated in four calendar-period defined cohorts. Each patient was matched with ten non-PsA individuals from the general population cohort (GPC). The cumulative incidences of any joint and joint-sacrificing surgery, respectively, were estimated using the Aalen-Johansen method.

Results From 1996 to 2017, 11 960 PsA patients (mean age 50 years; 57% female) were registered. The IRR of any joint surgery was twice as high for PsA patients compared with GPCs across all calendar periods. Among patients with PsA, 2, 10 and 29% required joint surgery at 5, 10 and 15 years after diagnosis. The risk of surgery in PsA patients diagnosed at 18–40 years was higher (22%) than in GPC 60+ year old (20%) after 15 years of follow-up.

Conclusions The use of joint surgery among PsA patients remained around twofold higher from 1996 to 2012 compared with GPC. After 15 years of follow-up, nearly 30% of the PsA patients had received any surgery, and even a person diagnosed with PsA at the age of 18–40 years had a higher risk of surgery than GPCs of 60+ year old. Thus, the high surgical rates represent an unmet need in the current treatment of PsA.

  • psoriatic arthritis
  • orthopaedic surgery
  • DMARDS (biologic)
  • epidemiology

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  • Handling editor Josef S Smolen

  • Contributors JG-M, RLC and LD had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. JG-M, RLC and LD: study concept and design. RLC and LD: acquisition of data. RLC: statistical analysis. All authors: interpretation of data; critical revision of the manuscript for important intellectual content. JG-M: drafting of the manuscript. LD and LEK: study supervision.

  • Funding The study was funded by The Oak Foundation and Independent Research Fund Denmark (DFF-6110-00608).

  • Competing interests JG-M has received speaking fees from AbbVie, Eli Lilly and BK Ultrasound outside the present work. RLC has no competing interests. LEK has received fees for speaking and/or consultancy from Pfizer, AbbVie, Amgen, UCB, Celgene, BMS, Biogen, Sanofi, MSD, Novartis, Eli Lilly, Janssen Pharmaceuticals. LD has received speaking fees from UCB, MSD, Eli-Lilly and Janssen Pharmaceuticals outside the present work.

  • Patient consent for publication Not required.

  • Ethics approval According to Danish legislation, the registration and publication of data from national registers do not require patient consent or approval by Ethics Committees. Approval was given by the Danish Data Protection Agency (HGH-2017-122, med I-Suite nr: 06047).

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

  • Data availability statement No data are available.

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