The Portuguese Survey on Anticoagulated Patients Register (START-Portugal-Register)

Anticoagulants are used to prevent thrombotic events in patients with predisposing factors. However, the use of such therapies is associated with bleeding complications, which can be a serious safety issue. Thus, it is important to evaluate the safety and effectiveness of such therapies based on data collected in clinical practice in order to generate relevant scientific data that could be used to support clinical and regulatory decisions.

This is an open, prospective, multicenter, observational cohort study that aims to prospectively record the clinical history of adult patients receiving anticoagulant treatment, irrespectively of the prescribed drug and the indication for its use.

* The Portuguese Survey on anTicoagulated pAtients RegisTer (START-Portugal-Register) is an open, prospective, multicenter, observational cohort study that intends to record the clinical history of adult patients receiving anticoagulant therapies, providing real-world data on the safety and effectiveness of such therapies, as well as to serve as the starting point of collaborative clinical studies, enabling their planning and execution.
* The START-Portugal-Register is designed solely for observational purposes; it is not intended to have any influence on the treatment of included patients.
* Objectives:

  * To prospectively record the clinical history of adult patients receiving anticoagulant treatment, irrespectively of the prescribed drug and the indication for its use.
  * To enhance the understanding of risks and benefits associated with the use of anticoagulant drugs in routine clinical practice;
  * To prospectively record decisions and reasons guiding physicians' decisions in order to manage anticoagulant treatment options in routine clinical practice;
  * To improve knowledge on the epidemiologic, diagnostic and clinical features of thrombotic diseases;
  * To generate real-world evidence on the safety and effectiveness of anticoagulant drugs, therefore contributing to support informed clinical decisions.
* The START-Portugal-Register is open to the participation of clinical centers and individual physicians that are involved in the management of patients undergoing anticoagulant treatment.
* Patients who sign the informed consent and fulfil the inclusion/exclusion criteria will be enrolled in the study and considered for data analysis.
* Follow-up: mandatory for at least 12 months. Nevertheless, a long-term follow-up is recommended for patients who receive an indefinite anticoagulation treatment. The START-Portugal-Register sets itself an indefinite time limit.
* A descriptive analysis will be conducted for all study variables. A propensity score model will be applied to compare the safety and efficacy of the different anticoagulant treatments.

Eligibility Criteria:
Inclusion Criteria:

* Aged ≥18 years;
* Patients who, at the time of inclusion, have been receiving for no more than 30 days or are about to start anticoagulation therapy - irrespectively of the prescribed drug, the dosage, and the indication for its use;
* Availability to sign an informed consent form.

Exclusion Criteria:

* Not available for follow-up and constant monitoring;
* Participation in phase II or III clinical studies\*;
* Life-expectancy \<6 months, non-residents in the Participant region, or planning to leave in the next 6 months.