A Digital Exercise Intervention in Patients With Spondyloarthritis

Main objectives: To assess if a digital personally tailored exercise program with remote follow-up can reduce disease activity measured by ankylosing spondylitis disease activity score (ASDAS) in patients with recently diagnosed axial spondyloarthritis (axSpA).

Main inclusion criteria Adults (> 18 years) with clinical diagnosis from a rheumatologist of axSpA within the last 2 years of inclusion also fulfilling the ankylosing spondylitis disease activity score (ASAS) classification criteria, who are biologic disease modifying anti-rheumatic drugs (bDMARD) naïve, and have an active disease (ASDAS ≥ 1.3)

Main exclusion criteria:

Active iridocyclitis, c-reactive protein (CRP) > 30, contraindication to high intensity interval training

Primary outcome Proportion of participants in ASDAS inactive (ASDAS < 1.3) at 3 months

Number of participants: 260 (with an anticipated drop-out rate of 15%)

Study design: A two-arm multi-centre, clinical trial, randomization 1:1 to either digital exercise intervention with remote follow-up or usual care.

Intervention: Exercise delivered through an application and with personalised follow-up by a coach through remote sessions (the participant and SPARK-coach are not at the same physical location) weekly. The exercise is progressively tailored to the fitness level of each participant. The program consists of 5 session per week on 3 different days including: two sessions with HIIT, 2 sessions with strength exercise, and one session with an aerobic exercise at moderate intensity. Goal for HIIT is 10 minutes two times per week at 85-95% of maximal heart rate (20 minutes in total). The exercise will be performed at a location of the participants' choice and data will be logged by a sports watch.

Efficacy assessments: ASDAS disease activity measure (4 patient reported questions and measure of CRP), Bath ankylosing spondylitis disease activity index (BASDAI).

Physical measure: cardiorespiratory fitness, in a subset of participants direct cardiopulmonary testing, muscular strength tests.

Psychological measures: Warwick and Edinburgh mental wellbeing scale (WEMWBS), EuroQol (EQ5D).

Medication: use of bDMARDs, use of NSAID

Safety assessments General physical examination and vital signs, laboratory tests as a part of usual clinical care, record of adverse events and serious adverse events, magnetic resonance imaging (MRI).

Inclusion criteria

• axSpA diagnosis within the last two years by a rheumatologist according to the ASAS criteria of 2009
• active disease (ASDAS > 1.3)

Exclusion criteria

• Active uveitis.
• CRP > 30.
• Former or current use of bDMARDs.
• Pregnancy or planned pregnancy within 6 months from inclusion.
• Absolute and relative contradictions to high intensity exercise according to the American College of Sports Medicine (ACSM)
• Other serious disease such as cancer.
• Patients incapable to follow the protocol or the control set-up with remote monitoring.