Thrombotic thrombocytopenic purpura (TTP) is a rare blood disorder. In TTP, blood clots form in small blood vessels throughout the body. The clots can limit or block the flow of oxygen-rich blood to the body's organs, such as the brain, kidneys, and heart. People who have TTP may bleed inside their bodies, underneath the skin, or from the surface of the skin. When cut or injured, they also may bleed longer than normal. TTP usually occurs suddenly and lasts for days or weeks, but it can continue for months.
Many people who have TTP have frequent repeat episodes that need to be treated. As a result, serious health problems can develop and cause a significant burden on healthcare facilities and a substantial increase in hospital costs, hospital length of stay, and contribute to death.
This study aims to determine the size of the TTP population group in England and describe its profile and associated risk factors. Further, we shall determine the health care resource use and costs and clinical outcomes associated with TTP.
This study should be able to provide an in-depth understanding of TTP in England considering that this condition is rare, and the profile may not be very well understood. This will trigger further research and inform health policy, treatment and clinical management options, especially targeting patients with risk factors to enable better outcomes in turn reducing complications and death associated with TTP.
The last 20 years have been marked by widening the knowledge base of the association between TTP and a disintegrin and metalloprotease with thrombospondin type 1 repeats, member 13 (ADAMTS13). Based on this better understanding of the pathophysiology of TTP combined with improved reporting of TTP in primary care, major advances in the comprehension of this historically fatal disease related to widespread microvascular platelet thrombi have been made. This has allowed a significant improvement in both diagnosis and therapeutic management of TTP. Although the pathogenesis, overall incidence, aetiology and presentation of TTP are now better understood, there is still limited knowledge on the associated mortality and survival rates, co-morbidities and healthcare resource use and, costs of TTP in England.
This will be a descriptive study which aims to determine which patients were diagnosed with TTP and determining the incidence and prevalence in different age groups, pre-diagnosis risk factors, co-morbidities, mortality, survival rates and health care resource use and costs. The study design has been chosen as this is appropriate for data extracted from healthcare datasets that already have data collected retrospectively. This will be done by creating a cohort of TTP patients using read codes reported in the primary care dataset. CPRD-HES linked dataset has been chosen due to the availability of good quality data for prescriptions, comorbidities, procedures, demographics, costs, complications, and resource use
We shall describe the cohort in terms of patient demographic characteristics, prevalence of comorbidities and selected risk factors. Health care resource usage for the cohort will be calculated and reported for inpatient admissions, outpatient appointments, A&E attendances, and primary care appointments, tests and prescriptions. Outcomes will be described as total, means, medians, percentage or rates as appropriate.
Prevalence of TTP; Prevalence of recurrence annualized incidence; Prevalence of co-morbidities and risk factors in the cohort (pregnancy, Cancer, HIV, SLE/Lupus, Sepsis, previous chemotherapy, previous stem cell transplant and previous use of quinine); Demographics (Mean and median age on inclusion, age distribution by decade, percent males, deprivation, total, mean and median follow-up, Ethnicity, Deprivation (IMD), Mortality rate, age at Mortality, survival at 5 and years, prevalence of peripheral artery disease (PAD) within the cohort, prevalence of Myocardial Infarction (MI) within the cohort, prevalence of Arrhythmia within the cohort, pregnancy loss, New-onset of hypertension, Anxiety/depression, cognitive impairment); Healthcare resource outcomes (prescriptions issued in primary care, procedures in secondary care, total appointments and cost in primary care, outpatient appointments, A&E attendances, inpatient admissions, inpatient length of stay, inpatient HRG tariffs, prior hospitalisation); Clinical outcomes (mortality)
Adrian Paul J. Rabe - Chief Investigator - Health iQ Ltd ( UK ) t/a CorEvitas
Adrian Paul J. Rabe - Corresponding Applicant - Health iQ Ltd ( UK ) t/a CorEvitas
Gulsah Akin Unal - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
Gulum Alamgir - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
James Tilbury - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
Jay Were - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
Gulsah Akin Unal - Collaborator - Health iQ Ltd ( UK ) t/a CorEvitas
HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;ONS Death Registration Data;Patient Level Index of Multiple Deprivation