Exposure to beta-blockers and survival in breast cancer patients: A cohort study using the UK General Practice Research Database.

Study type

• Study type:
  Non-interventional study
• Scope of the study:
  Disease epidemiology

Non-interventional study

• Non-interventional study design:
  Case-control

Study drug and medical condition

• Medical condition to be studied:
  Breast cancer female

Population studied

• 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)
• Estimated number of subjects:
  46000

Study design details

• Main study objective:
  The primary objectives of the proposed research are to examine whether female breast cancer patients who are exposed to beta-blockers have reduced cancer-specific mortality rates, all-cause mortality rates and recurrence rates.
• Outcomes:
  Breast-cancer specific death, All cause mortalityBreast cancer recurrence
• Data analysis plan:
  In the primary analysis the main exposure will be beta-blocker usage determined from GP prescribing data. The main analysis will be conducted on beta-blocker prescriptions in the period following diagnosis of cancer excluding the year prior to cancer death (or censoring). Packages and tablets of prescriptions for beta-blockers will be converted to daily defined doses (DDDs). Separate analyses will be conducted by type of beta-blockers based upon cardioselectivity and ISA activity (categorisations of beta-blockers shown in Appendix 1). A secondary analysis will be conducted on beta-blocker prescriptions in the period prior to cancer diagnosis (in patients registered for at least one year at their GP practice, to ensure prescriptions are recorded).