HAT Score for Haemorrhage After Thrombolysis: Clinical Guide

Clinical guide to HAT Score for Haemorrhage After Thrombolysis including calculation, interpretation, assumptions, limitations and references.

Estimates haemorrhage risk after intravenous thrombolysis for acute ischaemic stroke.

Overview

Estimates haemorrhage risk after intravenous thrombolysis for acute ischaemic stroke.

Clinical Significance

Higher HAT scores indicate greater risk of haemorrhagic transformation after thrombolysis.

When to Use

  • Use as structured clinical decision support when the required data are available and reliable.

How It Is Calculated

  • The displayed variables are combined using the published equation, decision rule or weighted point system.

Interpretation

  • Higher HAT scores indicate greater risk of haemorrhagic transformation after thrombolysis.

Worked Example

Enter verified patient data in the displayed units; MedicalC applies the published model.

Limitations

  • Risk and classification tools can be misapplied outside their validated population.
  • Missing, estimated or non-contemporaneous data may materially change the result.

Clinical Pearls

  • Document the inputs, units, date and clinical setting with the result.
  • Use serial scores only when the same instrument and measurement method are used consistently.

Common Mistakes

  • Using the tool without confirming entry criteria.
  • Using approximate or incorrectly converted values.
  • Treating a prognostic score as a standalone treatment decision.

Frequently Asked Questions

What does this tool calculate?

Estimates haemorrhage risk after intravenous thrombolysis for acute ischaemic stroke.

Can this result be used alone?

No. Interpret it with the full clinical assessment, applicable entry criteria and current guidance.

References

  1. Lou M et al. Neurology. 2008;71:1417-1423. — Primary or supporting reference for the implemented model.

Reviewed by: MedicalC Clinical Editorial Team
Last reviewed: July 2026

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