One of the most important questions in cancer research is what happens when a diagnosis is delayed? Unlike some cancers with clearer screening pathways or referral pathways, estimating diagnostic delay in leukaemia (and blood cancers more generally) is particularly challenging. People often see their GP several times before being referred, the time to diagnosis is typically longer and they are also less likely to be fast-tracked for tests than patients with other cancer types.
To explore the impact on potential delays on both individuals and the NHS, the Health Economics Unit (HEU) was commissioned by Leukaemia UK to examine how patterns of healthcare use, costs and survival differ between those with evidence of missed diagnostic opportunities and those diagnosed promptly.
Building a picture of diagnosis with data
The HEU analysed linked primary and secondary care data (using CPRD, a nationally representative dataset) on people newly diagnosed with acute myeloid leukaemia (AML) between 2015 and 2023.
To identify delayed cases, the HEU’s analysts developed a set of proxy indicators for potential missed diagnostic opportunities, informed by NICE guidance, clinical expertise and pathway analysis of AML diagnoses.
To estimate service use and costs, the HEU looked at emergency admissions, planned hospital care, outpatient visits, and GP appointments in the three months before and six months after diagnosis. Statistical models were then used to estimate how much extra activity and cost was linked to delayed diagnosis.
For survival, the analysts applied Kaplan–Meier curves, Cox regression (with time-varying effects), and logistic regression at different follow-up points to assess differences between groups.
Understanding the patient and economic impacts
The analysis showed patients who experienced delays in diagnosis tended to use services more frequently. They had more GP appointments and outpatient visits, pointing to repeated contacts, for example, where symptoms were not escalated promptly. Once diagnosed, this group required more intensive hospital care, both planned and emergency, reflecting the higher burden of disease when recognition came late.
The economic consequences are also significant. Across England, reducing delays could prevent around 4,100 healthcare contacts each year and save the NHS an estimated £1.7 million.
Survival patterns tell an important part of the story. For patients with evidence of missed opportunities, there was no immediate increase in deaths after diagnosis. Instead, their outcomes worsened steadily, and by one year they were 22% more likely to have died. In contrast, those diagnosed through emergency presentation faced a very high risk of death in the first month, more than double that of non-emergency cases. But among those who survived beyond this critical early period, survival was closer to patients diagnosed through planned routes.
Driving change
The results of this work were used by Leukaemia UK as a basis of a nationwide call for better leukaemia diagnosis in the UK, which was picked up by major news titles including The Independent and the Daily Mail.
References
Black GB, Boswell L, Harris J, Whitaker KL. What causes delays in diagnosing blood cancers? A rapid review of the evidence. Primary Health Care Research & Development. 2023;24:e26. doi:10.1017/S1463423623000129: https://pubmed.ncbi.nlm.nih.gov/37039465/
Clinical Practice Research Datalink (CPRD). CPRD Aurum and GOLD databases. Medicines and Healthcare products Regulatory Agency (MHRA). Available from: https://www.cprd.com
NICE, 2025. Haematological cancers: recognition and referral. https://cks.nice.org.uk/topics/haematological-cancers-recognition-referral/