Identifying diagnosis delays and treatment gaps in PsA: expert commentary

People with psoriatic arthritis (PsA) experience longer waits for diagnosis and receive less intensive treatment than those with rheumatoid arthritis, according to a major study from the University of Bath. Study lead, Dr William Tillett, discusses how the research highlights missed opportunities for early intervention in PsA, as well as actions for clinical teams to optimise patient experiences and improve quality of life.

Psoriatic arthritis (PsA) can have a significant impact on people’s lives, making it difficult to work and manage everyday activities. Affecting up to 30% of individuals with psoriasis, there are around 190,000 adults in the UK living with PsA.

It is a highly variable disease with distinct phenotypes. Approximately 60% of those affected develop polyarticular disease, leading to impaired quality of life, physical function and employment disability.

It has previously been shown that patients with PsA have a longer time to diagnosis than those with rheumatoid arthritis (RA), but no research has yet determined where the delays occur or the full extent of the impact.

As such, our recent analysis compared the time to diagnosis, initial treatment and outcomes in patients with PsA and RA to shed light on these issues and highlight opportunities for improvement.

The PsA patient cohort

Drawing on data from the National Early Inflammatory Arthritis Audit, our study included patients diagnosed between May 2018 and 31 October 2019, allowing adequate time for follow-up data collection before the onset of the Covid-19 pandemic.

During this period, more than 2,000 people with PsA were matched by age and sex with a similar number of RA patients, including 1,250 individuals with polyarticular disease.

We collected audit data from patients aged 16 years and older who attended specialist rheumatology centres in England and Wales for their first assessment of suspected inflammatory arthritis. Demographic and diagnostic details were recorded at the initial outpatient appointment, along with symptom duration before referral and the time from GP presentation to diagnosis.

Clinical assessments included 28 tender and swollen joint counts, patient global health scores, erythrocyte sedimentation rate and/or C-reactive protein, relevant comorbidities, and initiation of disease-modifying antirheumatic drugs (DMARDs) or corticosteroid therapy.

Clinical and patient-reported outcome measures were collected at baseline and, where available, at three- and 12-month follow-ups. Patients also completed questionnaires evaluating the impact of the disease on disability, work ability and mental health.

Clinical findings and challenges in PsA

The results, published in the Annals of the Rheumatic Diseases, showed that people with PsA waited longer before consulting their GP and experienced further delays once referred to specialist care. On average, the time from GP presentation to diagnosis was around three weeks longer for PsA than for RA.

The study recognises that PsA symptoms can be harder to recognise than those of RA and may include psoriasis, joint stiffness, fatigue and subtle nail changes, which are often mistaken for less severe conditions and can therefore delay healthcare access.

In some cases, inflammation affecting specific joints, such as the spine, may not be immediately apparent and will require imaging to identify any damage. Again, these scans are frequently delayed, sometimes occurring long after patients first become aware of symptoms.

Treatment differences were also apparent: just over half (54%) of PsA patients started DMARD therapy at diagnosis, compared with more than two-thirds (69%) of RA patients.

Corticosteroid use was less common in PsA, possibly due to concerns about triggering psoriasis flares. Although most patients agreed to a treat-to-target plan, improvements in disease activity over the first three months were milder in PsA. Patients with RA had a higher Disease Activity Score 28 at baseline, but by three months, the average score was 0.27 higher in patients with PsA (95% CI, 0.13–0.4).

These findings raise the possibility that people with PsA may miss the benefits of rapid treatment intensification during the early ‘window of opportunity’ in inflammatory arthritis. Delayed diagnosis and undertreatment are known risk factors for irreversible joint damage, reduced function and long-term disability.

Improved support for clinicians and patients

Our study highlights the need for better support for clinicians, improved access to scans and a focus on early, intensive treatment before structural damage occurs. Previous research by our group and others shows that delays of just six months can result in worse physical function for patients 10 years later, making timely diagnosis and treatment essential.

Improving patient education around PsA symptoms may also help to support earlier diagnosis and treatment and therefore strengthen longer-term outcomes.

For the clinical team, improving awareness of PsA symptoms in primary care and streamlining referral pathways to ensure timely access to specialist treatment could help reduce long-term disability and improve quality of life for people in the UK living with PsA.

Take-home messages

• Patients with PsA experience longer times to diagnosis than those with RA, both before presenting to primary care and after referral to secondary care
• Limited awareness and symptom recognition may be key barriers, as patients take longer to present to GPs with their symptoms
• At diagnosis and during early follow-up, PsA patients are less likely than RA patients to be prescribed DMARDs or corticosteroids, despite similar disease activity
• Fewer PsA patients received combination DMARD therapy, potentially contributing to poorer short-term outcomes
• Delays in diagnosis and less intensive therapy are associated with worse short-term outcomes, highlighting the importance of timely intervention to prevent long-term disability
• Improving awareness of PsA symptoms and optimising diagnostic and treatment pathways are essential to reduce delays and improve disease management.

Author

Dr William Tillett MBChB PhD FRCP
Consultant rheumatologist, Royal National Hospital for Rheumatic Diseases and senior lecturer in the Department of Life Sciences, University of Bath, UK