Non interventional post-authorisation safety study (PASS) to define the incidence of and potential risk factors for procedure-related neurological adverse events (AE) in patients undergoing ultrasound guided foam sclerotherapy (UGFS) for the treatment of lower limb varicose veins (VV) using Fibrovein 3% and 1% (sodium tetradecyl sulphate, STS, injection) incorporating a drug utilisation study (Fibrovein PASS)

Study type

• Study topic:
  Disease /health condition

  Human medicinal product
• Study type:
  Non-interventional study
• Scope of the study:
  Assessment of risk minimisation measure implementation or effectiveness

  Drug utilisation
• Data collection methods:
  Primary data collection

Non-interventional study

• Non-interventional study design:
  Cohort

  Other
• Non-interventional study design, other:
  Post-authorisation safety study

Study drug and medical condition

• Medicinal product name, other:
  Fibrovein
• Medical condition to be studied:
  Varicose vein

Population studied

• Short description of the study population:
  Adult (18 years and over) non-pregnant, non-breast-feeding, patients who are undergoing ultrasound guided foam sclerotherapy (UGFS) with Fibrovein for lower limb varicose veins (VV).
• Age groups:
  • 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:
  Other
• Special population of interest, other:
  Varicose vein patients
• Estimated number of subjects:
  10000

Study design details

• Main study objective:
  1. Define the incidence of procedure-related neurological AE in patients undergoing UGFS for lower limb VV using Fibrovein2. Characterise these AE in terms of type, severity, duration, treatment and clinical outcome3. Describe the relationship, if any, between procedure-related neurological AE and patient and treatment characteristics4. Describe the PMA “real world” use of Fibrovein for UGF
• Outcomes:
  Procedure-related neurological AE in patients undergoing UGFS for lower limb VV using Fibrovein
• Data analysis plan:
  Statistical advice has been sought regarding the sample size required to define, within reasonable CI, the incidence of neurological AE. An event rate of 0.3% equals 30 AE in 10,000 treatments. There is a 50% chance of observing > 30 AE, and a 20% chance of observing > 35 AE. There is, therefore, an 80% chance (power) of observing < 35 AE in association with 10,000 UGFS treatments. If 35 AEs were observed in association with 10,000 UGFS treatments, the 95% confidence intervals would range from 0.24% to 0.49%. This would provide significant (P<0.05) evidence that the rate is less than 0.5%. In other words, if the incidence of procedure-related neurological AE in association with UGFS is 0.35%, a sample size of 10,000 treatment sessions would provide the study with an 80% chance (power) of showing that the rate was significantly below 0.5% at the 5% significance level.