The Southampton Traffic Light (STL) Calculator

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

Go to CalculatorLiver disease develops silently and presents late with end-stage disease; as a result, one-third of new admissions die within the first few months, and death rates have doubled in the last 15 years. All liver diseases damage the liver by scarring or fibrosis, and the Southampton Traffic Light Test predicts the level of scarring as follows:

  • Green – No evidence of severe fibrosis but early damage cannot be excluded
  • Amber – Liver fibrosis likely but not certain
  • Red – Fibrosis almost certain, possible severe fibrosis or cirrhosis

With liver problems due to alcohol or obesity the main treatment is to stop drinking and to lose weight. For alcohol related liver disease we have shown that feeding back an Amber or Red Traffic Light result doubles the number of patients who are drinking safely a year later.

The Traffic Light test is not a perfect test, it has some false negatives and positives just like any test in medicine, but a green test is pretty good at excluding severe disease and a red test is a good reason to refer the patient to a liver clinic unless you are absolutely happy that you have clear diagnosis and management plan. For patients with an amber test, reduce any lifestyle risk factors if you can, check you are certain that you excluded treatable liver diseases for example: autoimmune liver disease, viral hepatitis and metabolic liver diseases, and repeat the test after a few years if the risk factors remain. The full BJGP paper for the Southampton Traffic light can be accessed here:

Go to CalculatorPlease ensure that you have read the full paper before using the traffic light test result to aid you clinical decision making.

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.