Despite productivity gains exceeding the Government's 2% target, the overall waiting list fell marginally from 7.5m to 7.4m between March 2024 and March 2025.

The percentage of patients waiting less than 18 weeks for treatment has shown similarly sluggish progress, rising from 57.2% in March 2024 to 59.8% in March 2025 and 61.8% in September 2025, still far from the NHS constitutional standard of 92%.

The analysis says the divergence between productivity and waiting list performance cannot be explained by changes to NHS funding, growth in referrals to the waiting list or increases in emergency hospital activity. It argues it is being driven by patients on average receiving more hospital appointments and operations before leaving the waiting list. In 2024–25, the number of outpatient appointments grew by 9.4%, while the number of completed waiting list pathways grew by only 4.0%.

The IFS says if the number of completed waiting list pathways had instead grown in line with hospital activity, the waiting list would have been around 1m cases lower by now.

Olly Harvey-Rich, a research economist at IFS and an author of the comment, said: ‘It is of course good news that hospital productivity has been rising. But so far, this has not resulted in materially lower waiting times for patients. That's not because lots more patients are joining the waiting list, but instead because the average patient is having more appointments and operations before being discharged.

‘For a Government that has set so much stock in its ambitions to cut NHS waiting times, understanding – and potentially reversing – this trend will be of crucial importance. Ultimately, the NHS needs to ensure that the right activity is being delivered for patients to complete their pathways, rather than simply delivering more activity.'

Liberal Democrat Health Spokesperson, Helen Morgan, said: ‘This is a clear symptom of how the Government is refusing to tackle the underlying problems in our health service, with patients paying the price. They are failing miserably to end the crisis in general practice, public health and in social care. As a result people are getting sicker for longer, meaning more intensive treatment and longer hospital stays. All while waiting lists continue to balloon.

‘Our NHS needs transformative change but Labour just don't seem up to it and are in total denial. It's time to invest in general practice so everyone can see a GP within 7 days or 24 hours if urgent, and to end the crisis in care so tens of thousands more people can go home, rather than deteriorate for days, weeks and months on a hospital ward.'