Epidemiology of thrombotic thrombocytopenia syndrome in integrated health-care database in England Secondary data analysis using a cohort design (Epidemiology of TTS)

Study type

• Study topic:
  Disease /health condition
• Study type:
  Non-interventional study
• Scope of the study:
  Disease epidemiology
• Data collection methods:
  Secondary use of data

Non-interventional study

• Non-interventional study design:
  Cohort

  Other
• Non-interventional study design, other:
  Retrospective study

Study drug and medical condition

• Medical condition to be studied:
  Thrombosis with thrombocytopenia syndrome

Population studied

• Short description of the study population:
  The study population comprised of patients aged 16 years or older diagnosed with thrombocytopenia, thrombotic thrombocytopenia, and thromboembolism identified from the integrated databases in England. ; Inclusion criteria: ; - A minimum of 12 months medical history prior to the start of the study period; ; Exclusion criteria:; - Less than 12 months of prior history at start of each perspective study period.
• Age groups:
  Adolescents (12 to < 18 years)

  Adults (18 to < 46 years)

  Adults (46 to < 65 years)

  Adults (65 to < 75 years)

  Adults (75 to < 85 years)

  Adults (85 years and over)
• Special population of interest:
  Renal impaired

  Hepatic impaired

  Immunocompromised

  Pregnant women
• Estimated number of subjects:
  9000000

Study design details

• Main study objective:
  The overall objective is to estimate event rates and describe characteristics of patients with a record for TTS, thromboembolism, or thrombocytopenia, in the general population of England.
• Outcomes:
  Thrombotic thrombocytopenia syndrome, thromboembolism or thrombocytopenia
• Data analysis plan:
  Unadjusted incidence rates of TCP, TE, and TTS will be calculated with associated Poisson exact 95% confidence intervals (CI) by dividing the number of incident events by the person-time at risk (presented per 100,000 person years). Logistic regression analysis will be used to assess the association between covariates and TTS, by calculating odds ratios (OR) with 95% CI.