Exposure to combined oral contraceptives and risk of venous thromboembolism: a protocol for nested case-control studies using the QResearch and the CPRD databases.

ABSTRACT:

Introduction

Many studies have found an increased risk of venous thromboembolism (VTE) associated with the use of combined hormonal contraceptives, but various methodologies have been used in the study design relating to definition of VTE event and the selection of appropriate cases for analysis. This study will focus on common oral hormonal contraceptives, including compositions with cyproterone because of their contraceptive effect and will perform a number of sensitivity analyses to compare findings with previous studies.

Methods and analysis

2 nested case-control studies will be based on the general population using records from UK general practices within the QResearch and Clinical Practice Research Datalink databases. Cases will be female patients aged 15-49 with prima

SUBMITTER: Vinogradova Y 

PROVIDER: S-EPMC3987715 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature