Study using OpenSAFELY shows change in diagnosis rates for autoimmune rheumatic diseases since COVID-19 pandemic

New research using OpenSAFELY has shown that diagnosis rates for several autoimmune rheumatic diseases, including rheumatoid arthritis, remain below expected levels five years after the start of the COVID-19 pandemic.

The study, led by researchers from King’s College London, and published in The Lancet Rheumatology, provides the first large population-level assessment of how diagnosis rates for autoimmune rheumatic diseases have changed since the pandemic.

Using OpenSAFELY to analyse NHS data from more than 23 million adults in England, researchers studied diagnosis rates for 10 autoimmune rheumatic diseases between 2016 and 2025. While diagnosis rates recovered for some conditions following the pandemic, significant gaps remain for diseases including psoriatic arthritis, rheumatoid arthritis and giant cell arteritis.

Diagnoses fell sharply during the first year of the pandemic across almost all conditions studied, likely reflecting disruptions to healthcare services and limited access to assessment and diagnosis. Although rates later increased, diagnosis gaps remained by March 2025 for several conditions.

Psoriatic arthritis – a type of arthritis that can occur in people with skin psoriasis – showed the largest deficit, with diagnoses around 25 per cent below pre-pandemic levels, while rheumatoid arthritis diagnoses were approximately 10 per cent lower than expected.

Researchers also found fewer diagnoses of giant cell arteritis, a serious inflammatory condition that can cause permanent sight loss if not treated quickly. In contrast, diagnoses of axial spondyloarthritis – a type of arthritis that mainly affects the back in younger adults – increased above pre-pandemic levels, particularly among women.

Professor Ben Goldacre, Director of the Bennett Institute for Applied Data Science, said:

“We built OpenSAFELY from the ground up to protect patients’ privacy, while also making population GP data much easier for researchers to work with. Our privacy tools have earned the support of key stakeholders including professional bodies, citizens juries, and privacy campaigners. By doing that, we have been able to make lifesaving data securely available to approved users, in collaboration with NHS England. This study shows that when researchers analyse GP data safely, they can identify diagnosis gaps earlier, improve healthcare inequities, and make a real difference to millions of patients.”

Dr Mark Russell, rheumatologist and epidemiologist at King’s College London and lead author of the paper, said:

“These findings demonstrate the potential of population-scale health data to support disease surveillance, identify inequalities across patient groups, and help healthcare services monitor emerging trends more rapidly. This powerful information could then be used to target strategies towards improving diagnosis and care.”

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