Determining if Positive Predictive Value using Laboratory Risk Indicator for Necrotising Fasciitis is Applicable in Malaysian Patients with Necrotising Fasciitis

Introduction: Necrotising fasciitis (NF) is a rapidly progressive infection of the subcutaneous tissue and fascia which spreads rapidly. The scoring system of Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC) developed by Wong et al has been proposed as a tool for distinguishing NF and other soft tissue infections (STI) in Singapore. We set out to establish whether the LRINEC score is applicable in our Malaysian setting. Materials and Methods: A cross sectional study of all patients admitted to our hospital diagnosed with NF or To Rule Out NF (TRO NF) between January 1st 2016 to 30th June 2016. The sensitivity, specificity, positive and negative predictive values were then calculated for LRINEC score of ≥ 6 and ≥ 8. Results: Fourty-four patients were identified with the diagnosis of NF or TRO NF in the study. Twenty-seven patients (61.4%) were deemed post-operatively as having NF and 17 patients (38.6%) not having NF. A sensitivity of 59.3% and specificity of 47.1% when a LRINEC score of ≥ 6 was taken with positive predictive value (PPV) of 64.0% and the negative predictive value (NPV) of 42.1%. When score ≥ 8 was taken, the sensitivity was 48.1% and specificity of 58.8% with PPV of 65% and NPV of 41.7%. Conclusion: The low sensitivity and low PPV achieved in this study as well as other studies makes the LRINEC score unsuitable to be used solely to distinguish NF with other soft tissue infections.