The clinical utility of signs, symptoms and early warning scores, either individually or in combination, for predicting severe illness in the initial assessment of people aged 16 years or over with suspected acute respiratory infection: a rapid evidence synthesis

Project overview 

This work was undertaken to inform a National Institute for Health and Care Excellence guideline on the initial assessment of adults with suspected acute respiratory infection.

Status: completed

Contact: Rachel.churchill@york.ac.uk 

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What is the problem?

Acute respiratory infections, such as cold and flu, are common and can be caused by viruses or bacteria. People with symptoms of acute respiratory infection often go to their GP, who may advise them to stay at home (with or without antibiotics or antivirals), or might refer them to hospital if the infection is serious. Doctors assess the patient’s symptoms, or they may use a tool called an ‘early warning score’ to judge whether the infection is serious. Different signs, symptoms and 'early warning scores' may tell doctors different things about how best to care for patients with suspected acute respiratory infections. 

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What did we do?

We looked at published studies that have used different approaches to find how best to look after people with suspected acute respiratory infections. A systematic review is a research method where all relevant studies addressing a specific question are found and summarised using clear and documented methods. We aimed to use this method to rapidly summarise systematic reviews, and sometimes other types of research, that have assessed signs, symptoms and ‘early warning scores’ in adults with suspected acute respiratory infections in the community (i.e. not hospitalised patients). 

We wanted to see if using different approaches to making decisions about how to care for people with suspected acute respiratory infections are effective and cost-effective. We did this to support the National Institute for Health and care Excellence (NICE) to inform the development of a new guideline NICE Guideline 10376 – Acute Respiratory Infection in over 16s: Initial assessment and management. This guideline is intended to support decisions about care of people with suspected ARI and help improve services.

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What did we find?

We found nine systematic reviews and one cost-effectiveness study. Several different early warning scores for acute respiratory infection have been assessed in systematic reviews. Seven of the reviews assessed early warning scores in patients with community-acquired pneumonia. Good-quality reviews concluded that further research is needed to see how useful the ‘CRB-65’ and ‘Pneumonia Severity Index’ early warning scores are for assessing pneumonia severity in the community. Another good-quality review concluded that the ‘National Early Warning Score’ early warning score appears to be useful in an emergency department setting. A good-quality review found that individual symptoms are not very reliable for diagnosing pharyngitis caused by streptococcal bacteria in patients with sore throat; the review also found that the ‘Centor score’ can help doctors decide whether to prescribe antibiotics for pharyngitis. 

The cost-effectiveness study assessed clinical scores and rapid antigen detection tests (which test for substances that increase in our blood when we have certain infections) in patients with sore throat, and found that clinical scores may be cost-effective compared to delaying prescribing antibiotics.