Thousands of patients are being omitted from official health statistics because they are not seen by hospitals or GPs, according to a groundbreaking study of ambulance data in England. More than a third of people who made calls attended by Yorkshire ambulance service (YAS) last year – 288,000 of about 800,000 – did not go to hospital. Many of these patients had mental health issues. Some people were treated by ambulance staff at the scene, or later saw a GP or took themselves to A&E. But conditions that are not commonly treated in hospital, such as mental health issues, substance misuse or self-harm, are likely to be dramatically undercounted, according to the analysis by YAS and the Association of Ambulance Chief Executives (AACE). Take mental health issues in under-18s in Yorkshire and the Humber in 2022-23. NHS figures show that there were 870 hospital admissions yet YAS received about 3,300 calls. Verity Bellamy, senior public health analyst at YAS, said: “This suggests we’re missing almost three-quarters of those young people by just using hospital data.” The highest number of mental health calls was from girls and young women aged between 15 and 24 – about 13% of 50,000 calls. Bellamy said it might be the right thing for those young people not to be then admitted to hospital. “But if we want to measure the prevalence of mental health need in young people, we need to think about using ambulance data [as well as] hospital data.” She ran the study, presented at the NHS ConfedExpo in June, with YAS colleague Ruth Crabtree, who is also the AACE’s national lead for public health, and they plan to do an England-wide analysis of ambulance data. Crabtree said it was the first time an ambulance service had systematically examined its data in this way. “As a sector, we tend to measure performance and demand, rather than this kind of more upstream way of looking at things,” she said. “So it’s very interesting that Verity has come in and seen something that surprised her and that is quite different to what we’ve seen before.” Dr Steven Dykes, YAS deputy medical director, said that ambulances increasingly provided care on the scene to people who did not want to go to hospital, such as homeless people, refugees and older, more frail people. “One of the key things for us was that the ambulance rate for those in the most deprived areas is double that of the least deprived,” he said. “There’s a greater amount that [ambulance crews] are actually managing at home and when you see that in the data, it’s really quite shocking”. The analysis showed that 55% of all calls relating to mental health were for under-40s, with almost a quarter for under-25s. People in the poorest fifth of society were five times more likely to call an ambulance for a mental health concern. People in the most deprived areas also made up 40% of the 72,000 calls for breathing difficulties. “We understand why that might be. We have much higher smoking rates in the most deprived groups. We have people with more industrial jobs and poor quality housing. But we did see a similar pattern for young people as well, which we were quite surprised about. That doesn’t include smoking and doesn’t include longstanding disease,” Bellamy said. The analysis also revealed the knock-on impact of the dentistry crisis. YAS received more than 5,000 calls for toothache in under-10s, of which 64% were from the most deprived group, compared with 4% from the least deprived. Some of these issues are found elsewhere in other data, such as a Health Foundation report earlier this year which showed that one in three people aged 18-24 were reporting common mental disorders such as anxiety or depression, rising to 41% for young women. But Bellamy said the ambulance service could act as an “early warning system” for other parts of the health service. “We’re probably likely to see this before, perhaps, commissioners of mental health services, for example,” she said. “So we’re trying to share this data with the right bits of the system, so they can plan properly.” Dykes said YAS was working with mental health trusts and charities to help patients get better access to those services. “There’s a big problem with transition from child to adult services, which is this group of patients that we’re seeing here. Is it that the services just aren’t there for them and they fall in between the gaps in this age group? That’s why it’s important for us to turn this data around and reflect it back into the system.” Bellamy said: “We think a lot about how we get ambulances faster to people but actually, if we start thinking more upstream, we can get into prevention. And that’s a much better thing for people as well.”