Thalassaemia is a blood disorder passed from parents to children. People with thalassaemia produce either no or too little of a substance called haemoglobin, which carries oxygen around the body. Some people will have noticeable symptoms within months of their birth and others not until later in life. As a result of their lack of haemoglobin, people with thalassaemia may experience tiredness, weakness, and an irregular heartbeat. Often, they will require regular blood transfusions, and as a result of the transfusions people with thalassaemia may have other health problems including problems with their heart or liver. Due to the necessary treatment, symptoms of thalassaemia, and possible resulting health problems, people with thalassaemia need to attend healthcare often.
The level of haemoglobin and time at which the previously mentioned health problems develop are not well understood. We will use anonymous data from GP and hospital records from England to describe the occurrence of these health problems as well as death, the level of haemoglobin at which individuals with thalassaemia have problems, the burden a change in haemoglobin level has on the amount of healthcare attendance people with thalassaemia have, and the current treatment patterns for thalassaemia.
The results will increase understanding of how treatments that increase haemoglobin levels can be used to lower the occurrence of health problems and the burden on the healthcare system for people with thalassaemia, to guide possible improvements and standardisation of patient care and treatment to improve the well-being of people with the condition.
Thalassaemia syndromes are inherited blood disorders characterized by dysregulation of haemoglobin, resulting in ineffective red blood cell (RBC) production, reduced functional haemoglobin in RBCs, and anaemia. Individuals with thalassaemia can have transfusion-dependent thalassaemia (TDT) or non-transfusion-dependent thalassaemia (NTDT), depending on presentation and the need for regular transfusions. Complications can develop due to symptoms or treatment, leading to multisystemic manifestations of the disease.
In this retrospective cohort study, we will use linked data from Clinical Practice Research Datalink (CPRD) Aurum, Hospital Episode Statistics, Diagnostic Imaging Dataset, Office for National Statistics death registrations, and Index of Multiple Deprivation, to assess the association between a 1 gram per decilitre (g/dL) decrease in haemoglobin among patients with TDT and NTDT (separately) and percentage increase in symptoms, complications, comorbidities and mortality, along with healthcare resource use (HCRU) and cost in adults with NTDT and TDT using appropriate regression methodologies. We will compare incidence of symptoms, complications, comorbidities and mortality, along with HCRU and costs between adults with TDT or NTDT and without thalassaemia (matched on age, sex, ethnicity, CPRD practice, follow-up time). Poisson regression will be used to model occurrence of symptoms, complications, comorbidities, Cox proportional hazards regression will be used for the outcome of death, generalised linear models (GLM) with negative binomial distribution for HCRU events and GLM with gamma family for healthcare cost. We will explore treatment patterns for adults with thalassaemia, progression from NTDT to TDT and its effect on complications and mortality, indirect productivity loss due to sickness or engaging with healthcare services, and loss of future income due to long-term unemployment, medical retirement, or death.
The results will increase understanding of how treatments that increase haemoglobin affect risk of complications, mortality and healthcare burden for people with thalassaemia in England, to guide improvements and standardisation of patient care and treatment.
Key symptoms of thalassaemia (defined as fatigue, dyspnoea, syncope, and jaundice); Comorbidities and complications of thalassaemia; Mortality; Progression from non-transfusion-dependent thalassaemia to transfusion-dependent thalassaemia; Number of all-cause inpatient admissions; Costs of all-cause inpatient admissions; Length of all-cause inpatient stay in those with at least one inpatient admission; Number of all-cause outpatient visits; Costs of all-cause outpatient visits; Number of all-cause emergency care attendance; Costs of all-cause emergency care attendances; Number of transfusions; Costs of transfusion visits; Days between transfusions; Number of all-cause primary care consultations; Costs of all-cause primary care consultations; Number of primary care prescriptions (any); Number of iron chelation therapy prescriptions (desferrioxamine mesylate, deferiprone, deferasirox, dexrazoxane); Duration of iron chelators prescriptions; Number of MRI scans; Costs of MRI visits; Number of bone mineral density scans; Costs of bone mineral density scan visits; Cost of lost productivity; Lost future income
Jennifer Davidson - Chief Investigator - Health iQ Ltd ( UK ) t/a CorEvitas
Caitlin Winton - Corresponding Applicant - Health iQ Ltd ( UK ) t/a CorEvitas
Caoimhe Rice - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
Hannah Brewer - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
James Baird - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
Rebeka McClintock - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
Sara Carvalho - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
HES Accident and Emergency;HES Admitted Patient Care;HES Diagnostic Imaging Dataset;HES Outpatient;ONS Death Registration Data;Practice Level Index of Multiple Deprivation