Case study: Misinterpreted result

...Mr T is told he has tested positive for hepatitis B, but weeks later it appears an error has been made...

  • Date: 30 September 2021


Mr T works in a city centre fast food outlet. He presents at the practice with an apparent needle-stick injury sustained while disposing of rubbish bags from the toilet. Mr T is concerned over the risk of HIV or other infectious diseases.

The attending GP – Dr U – reassures Mr T that the risk is small and arranges blood tests to check for hepatitis A, B, C and HIV. A few days later the lab results come back stating:

Hep B surface antibody DETECTED: 68 iu/L. Previous vaccination then >100 iu/L desirable. Boost and recheck in 2-4 months. No previous vaccination or no response to booster, contact lab for past/current infection testing.

Dr U informs Mr T that he has tested positive for hepatitis B and arranges an urgent referral to the gastroenterology unit at the local hospital. More blood tests are arranged along with liver function tests. Mr T is advised to refrain from unprotected intercourse with his partner and she is requested to attend the practice for testing and vaccination.

Two weeks later Mr T phones the practice to say that he has not heard from the hospital. He is told the practice will chase the referral. Another two weeks pass and Mr T phones again to say he has still heard nothing from the hospital – and he states the situation is causing his family significant distress. Dr U investigates and discovers that the initial letter had been forwarded to the wrong department and he sends another letter requesting the referral be expedited.

Just over a week later the practice receives a letter from the hospital that states Mr T’s anti-HBS is positive at low titre and his anti-HBC is negative and liver functions are normal. This means he has not been exposed to hepatitis B virus and is not infected. The letter goes on to state that Mr T has probably been vaccinated in the past but his antibody titre is low and he therefore requires a booster.

Dr U contacts Mr T to inform him that he does not have hepatitis B and apologises for the error.

A month later a letter of claim is received at the practice from a solicitor alleging clinical negligence in the care provided to Mr T. It alleges breach of duty of care in failing to interpret the blood results correctly and the misdiagnosis of hepatitis B. The letter also contends that Dr U failed to consider Mr T’s full medical history, including previous vaccination for hepatitis B.

It is further alleged that these failings led to Mr T suffering a prolonged period of psychological stress and anxiety, also affecting his family and employment.


MDDUS acting on behalf of Dr U instructs a primary care expert to assess the case. In reviewing the notes she concludes that there was a clear breach of duty by Dr U in misinterpreting the first test results. The patient records also detail that Mr T had been vaccinated for hepatitis B four years previously.

The expert identifies further errors in practice systems as the follow-up blood test results had been correctly interpreted and filed as “normal” by another GP at the practice, who was unaware that Mr T had been diagnosed with hepatitis B and referred to gastroenterology.

MDDUS in agreement with Dr U and the practice decides to settle the case for a modest sum. The practice also undertakes a significant risk analysis in order to identify measures to prevent similar incidents in future.


  • Ensure test results are interpreted in the context of the full patient record.
  • Ensure results handling systems provide appropriate continuity of care.

This page was correct at the time of publication. Any guidance is intended as general guidance for members only. If you are a member and need specific advice relating to your own circumstances, please contact one of our advisers.

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