Pandemic linked to lasting drops in diagnosis rates for major conditions

There has been a lasting and disproportionate impact of the Covid-19 pandemic on diagnosis rates for conditions including depression, asthma and osteoporosis.

Depression is the most severely impacted, with almost a third fewer diagnoses than expected compared with pre-pandemic trends.

The King's College London study is the first to evaluate whether diagnosis rates have recovered after emerging from the pandemic. Published today in the British Medical Journal (BMJ), it uses anonymised data from over 29 million people in England.

The pandemic had an unprecedented impact on healthcare systems around the world, leading to abrupt decreases in diagnosis rates for a wide range of diseases.

Of the 19 major conditions analysed, diagnoses of depression were 27.7% lower than expected compared with pre-pandemic trends. Diagnoses were also lower than expected for asthma (16.4%), chronic obstructive pulmonary disease (COPD, 15.8%) and osteoporosis (11.5%).

The study also identified differences in how diagnosis rates recovered across ethnic and socioeconomic groups. While dementia diagnoses recovered to pre-pandemic levels for individuals of white ethnicity and those living in less deprived areas, they remained lower than expected among other ethnic groups and in more deprived communities.

Co-author Professor Sam Norton, Professor of Medical Statistics at King's College London, said: "The deficits in depression diagnoses were particularly striking and somewhat puzzling. After an initial decrease during the early pandemic, diagnosis rates partially recovered by late 2021, but have declined markedly since 2022. This pattern was most evident among younger adults aged 20 to 39 years, and among individuals of white or mixed ethnicity.

"This is difficult to reconcile with other indicators of mental health need. Disability benefit claims for mental health conditions have increased substantially over the same period, suggesting these declining diagnosis rates may not reflect improving mental health."

Diagnosis rates may be influenced by increasing pressures on the NHS, meaning it is taking longer for people to be formally diagnosed. It is also possible that more people are accessing mental health support without receiving a formal diagnosis of depression. Following a national drive to expand access to psychological therapies, referrals to NHS Talking Therapies services increased by nearly two-thirds between 2013 and 2024, with self-referrals accounting for almost 70% of all referrals.

The team also suggest that pandemic-related disruption could be behind the fall in diagnoses for asthma, COPD and osteoporosis. Backlogs in diagnostic testing for these conditions during the pandemic is likely to be a key factor, and the NHS has identified this as a priority area for improvement.

Further analysis revealed that chronic kidney disease (CKD) diagnoses have increased by 34.8% compared to expected levels.

Lead author Dr Mark Russell, consultant rheumatologist and epidemiologist at King's College London, said: "The rise in CKD diagnoses may reflect increased testing and greater awareness following guideline changes and the introduction of new treatments.

"It is also possible that the pandemic itself has contributed to an increase in CKD, either through the direct effects of Covid-19 infection or through delays in diagnosing related conditions such as diabetes."

The research team used OpenSAFELY, a highly secure and anonymised NHS data platform, to analyse disease trends for 29 million people between April 2016 and November 2024.

Dr Russell added: "This study highlights the incredible health data resources available within the NHS and demonstrates how real-time, anonymised data could be used safely and securely, without any individual patient data ever leaving the NHS system, to transform disease monitoring, enabling earlier identification of inequities and informing how care is delivered."