ASDAS-CRP Calculator

Overview

Calculates axial spondyloarthritis disease activity using patient-reported domains and CRP.

Clinical Significance

ASDAS <1.3 indicates inactive disease; 1.3–3.5 very high disease activity.

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 or weighted point system.

Interpretation

• ASDAS <1.3 indicates inactive disease; 1.3–<2.1 low, 2.1–≤3.5 high and >3.5 very high disease activity.

Worked Example

Enter verified patient data in the displayed units; MedicalC applies the published equation or point system.

Limitations

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

Clinical Pearls

• Document the input values, 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.
• Selecting overlapping findings that should be represented by the highest-scoring item only.
• Treating a classification threshold as a standalone diagnosis.

References

1. van der Heijde D et al. Ann Rheum Dis. 2009;68:1811-1818. — Primary or supporting reference for the implemented model.