Study finds more than 13,000 opioid deaths missing from official England and Wales figures

More than 13,000 opioid-related deaths in England and Wales were not captured in official statistics, new research from King's College London shared with the BBC found, suggesting the scale of the opioid crisis is substantially larger than government figures indicate.

Researchers from the National Programme on Substance Use Mortality at King's calculated there were 39,232 opioid-related deaths between 2011 and 2022 — more than 50% higher than previously reported by the Office for National Statistics. The study, which used coroners' reports and has been peer-reviewed and published in the International Journal of Drug Policy, attributes the undercount largely to the ONS not having access to detailed post-mortem and toxicology reports and to coroners often not naming specific drugs on death registrations.

The shortfall is significant in policy terms because more granular data on specific substances influences decisions about treatment, funding and policing. The number of opioid deaths per million people in England and Wales has almost doubled since 2012, the research found, and the revised totals suggest the problem is more acute than previously recognised.

The study focused on deaths involving opioids — a group that includes heroin and synthetic drugs such as fentanyl — and used coroners' records that often list individual substances in post-mortem findings and toxicology results. Those details are not routinely available to the ONS when it compiles national statistics, which typically rely on death certificates that sometimes record only a general cause such as 'drug poisoning' without identifying the specific drug.

The discrepancy means the government's headline figures on overall drug deaths, which do not name specific substances, are not affected, but officials and agencies that plan and fund specialist services often rely on the more detailed ONS breakdowns to allocate resources. King's also reported similar gaps for other drugs, estimating that 2,482 cocaine-related deaths were missed from ONS figures over the last decade.

Families of people who died say the undercount has real-world consequences. Hilary, whose son Ben died from a heroin overdose in 2018 at age 27, said his death was ruled "misadventure" and was not included in the official opioid statistics. She described Ben's long struggle with addiction, which began with cannabis in his teens and progressed to aerosols and heroin. Hilary said her family believes different treatment or support might have changed his course.

"Ben was just a very kind person. We miss him, we all miss him every day," she said. She recounted that her son had been accepted into a rehabilitation facility, but died shortly before he was due to enter, and that a reduced tolerance after a period of abstinence may have contributed to the fatal overdose.

Dr Caroline Copeland, who led the King's research, said accurate statistics are vital to effective policy. "Drug policies will not have the desired impact unless the true scale of the problem is known," she said, urging coroners to provide more detail on death registrations about the substances involved.

Political and policing figures called for action. Helen Morgan, the Liberal Democrat health spokesperson, said the government needed to investigate how the error occurred and to ensure the ONS can access the data it requires. David Sidwick, the drugs lead for the National Association of Police and Crime Commissioners and a Conservative police and crime commissioner, said more accurate data could support stronger bids for treatment funding and allow better decisions about services, including potential new treatment approaches such as long-acting buprenorphine injections.

The ONS, which co-operated with the research team, has previously warned that information provided by coroners on death registrations can lack detail about specific drugs. A spokeswoman said the more detail coroners provide about the drugs relevant to a death, the better the statistics will be to inform the government's drug strategy.

The reporting system in Scotland differs from that in England and Wales. Scotland has no coroners: National Records of Scotland compiles statistics and does receive more detailed pathology reports, according to the researchers, making direct UK-wide comparisons difficult because of differences in reporting arrangements.

The revelation of the undercount comes amid heightened scrutiny of the ONS, which has faced criticism for data quality and an independent review earlier this year that highlighted "deep-seated" problems. The Department of Health and Social Care said it was working with partners across health, policing and other services to reduce drug use, improve access to treatment and make communities safer, and indicated it was collaborating with coroners to improve reporting.

Experts say correcting the gap in substance-specific mortality data could help tailor treatment services, target harm-reduction measures and inform investment in frontline services. The King's researchers called for systematic access to post-mortem and toxicology reports or for more complete recording of specific substances on death registrations so public health interventions reflect the true scale and nature of drug-related harm.

The researchers stressed that while the study focused on opioids, the underlying issue — incomplete recording of specific drugs on registration documents — is likely to have led to undercounts for other substances, potentially skewing policy responses across the spectrum of drug harms.

A Department of Health and Social Care spokesperson reiterated its commitment to working with health services, policing and wider public services to drive down drug use and improve treatment access. Government officials have said they are engaging with coroners and the ONS to reduce gaps in the data, and that better information will support more effective planning and funding decisions.

The King's College study adds to a growing body of evidence suggesting official drug mortality statistics may understate specific substance-related deaths, a discrepancy that researchers and campaigners say should be addressed to strengthen public health planning and prevent further loss of life.

The study's authors and public health advocates say improvements in the flow of detailed forensic information to national statistical bodies, or changes to how coroners record the substances involved in deaths, are essential steps to ensure policy and funding decisions reflect the scale and character of the drug-related mortality problem.