The Southampton Traffic Light (STL) Calculator

The algorithm used within this calculator only works with assays done by Kings College Hospital London (originally University of Southampton University Hospital Trust, but they have changed the assay procedure). It cannot be used with individual test results from other hospitals.

Please enter data into the boxes as follows, only the data on platelet count, hyaluronic acid and collagen P3NP will be used to calculate the Traffic Light grade, the other clinical data is collected in order for us to gauge how the test is being used.

STL Score


Patient Risk

  • Red - high
  • Amber - intermediate
  • Green - low
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Kaplan Meier Survival Plot Info

Kaplan Meier survival plot of 2533 inpatients and outpatients seen in the Liver Unit of Southampton University Hospital with liver disease of varying aetiology according to the traffic light result. Patients in liver clinics are more unwell than those detected by screening in the community so we would not anticipate that such a marked effect on survival with a red result, the purpose of the chart is to demonstrate the ability of a red test to select those with a worse prognosis.

Updated analysis was performed in March 2013.

The Southampton Traffic Light (STL) Calculator

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