Recent advances in treatment and care have improved survival rates for children and young adults with severe blood disorders such as sickle cell disease (SCD), transfusion-dependent beta-thalassaemia (TDT) and acute leukaemia. However, their quality of life and reproductive and psychosocial outcomes are not yet well studied. For SCD and TDT, robust survival data are mainly limited to North America. Thus, there is a need to fill these knowledge gaps to guide improvements in care, address unmet clinical needs and rigorously assess the efficacy of emerging novel therapies.

This is an observational population-based mixed-methods study of individuals diagnosed with SCD, TDT or acute leukaemia when under the age of 18 in England, involving a data linkage component and a patient-reported outcomes measures survey. Data linkage-eligible participants will be identified from national and regional databases, including the Hospital Episode Statistics, Yorkshire Specialist Register of Cancer in Children & Young People and the National Congenital Anomaly and Rare Diseases Registration Service. Data linkage will be processed within the NHS England and the University of Leeds’ secure, trusted research environments. Data will be accessed without consent under section 251 and approval by the confidentiality advisory group. It will assess survival rates for SCD and TDT as well as clinical, educational and mental health outcomes for SCD, TDT and acute leukaemia diagnosed in childhood.

Survey-eligible participants for SCD, TDT and acute leukaemia cohorts will be checked for their suitability to participate by the North of England clinical care teams. An NHS-approved survey provider will facilitate data checks with the NHS National Data Opt-Out Service. Consent is required for participation in the survey and for subsequent data linkage to existing databases. Surveys are conducted in various formats (online, paper and phone), with reminders sent after 21 days. The survey will assess quality of life and psychosocial and reproductive outcomes. Participants can withdraw at any time, and support is available via telephone helplines.

The study has received ethical and information governance approval from the Health Research Authority (Reference 24/YH/0186) and the Confidentiality Advisory Group (CAG 24/CAG/0138) to process identifiable data without consent. Study results will be available to patients, physicians, researchers, stakeholders and others through open-access publishing, results sharing via media platforms and presentations at conferences and meetings.

To evaluate the cost-effectiveness of implementing a penicillin allergy assessment pathway (PAAP) versus usual care within the NHS.

A decision tree analysis over a 5-year time-period, informed by a randomised controlled trial (RCT) of PAAP and systematic review. Value of information analysis was also conducted to estimate the value of conducting a new trial.

Model inputs were informed by the ALABAMA RCT participants included in the primary analysis, 811 adults with penicillin allergy labels and recent antibiotic prescriptions, and data from published literature.

Participants in the ALABAMA trial included in the primary analysis: PAAP (n=401) and usual care (n=410).

Costs are presented in GBP (£) at 2022–2023 prices, quality-adjusted life years (QALYs), incremental cost-effectiveness ratio, incremental net monetary benefit (INMB), the probability of cost-effectiveness at the £20,000 and £30,000 per QALY threshold, and the cost effectiveness of a new follow-on trial.

PAAP had incremental costs of £–83 (probability of cost saving 47.5%) and incremental QALYs of 0.036 (probability of positive benefits 47.5%). The INMBs (probability of cost-effectiveness) were £806 (48%) and £1167 (48%) under the decision thresholds of £20,000 and £30,000 per QALY, respectively. PAAP was more cost-effective among females, people aged >65 years, and more frequent antibiotic users. A new follow-on trial involving 1267 participants was estimated to cost £2.4 million and, by reducing uncertainty in the evidence, would avoid £19.6 million in costs of incorrect management decisions for eligible patients over the next 10 years.

The PAAP was considered cost-effective, but significant uncertainty remained. Future trials with adequate power and longer follow-up are needed to determine the most cost-effective models for penicillin allergy testing.

ISRCTN20579216.