The government reported on the 1st of June 2021 that in the UK there were 5,683 new cases. This means that an individual tested positive and had the disease. 

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Sensitivity and specificity provide clarity in understanding the strengths of a test and how often a test generates correct results.  

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• Sensitivity 

Covid-19 patients are identified correctly with the disease.  

A/C= a 

Calculate percentage: a x 100 = % 

  

For example 90% sensitivity means that a correct positive result is given for 90% of the tests and 10% receive a false negative result  

 

• Specificity 

An individual DOES NOT have Covid-19 and will correctly receive a negative test result.  

E/F=b  

Calculate percentage: b x 100=%  

  

For example 90% specificity means that 90% of tests will give a correct negative result and 10% will incorrectly receive a positive result (false positive) 

 

 

Other useful statistics and term used by the media to report data:  

 

• Disease prevalence 

C/I=C x 100= %  

This means that prevalence is concerned with the measure of the burden of the disease and is interpreted as the percentage of population that truly has Covid-19 at one time.  In contrast:  

 

• Disease incidence is concerned with the new cases of disease occurring during a specified time. If number of cases increases the incidence increases, and vice versa.  

 

• Infection fatality rate (IFR) = Deaths/Cases= % (% is the number of people with SARS-CoV-2 have a fatal outcome); while the remaining % are those who recovered.  

 

• Death rate or Case Fatality Rate = number of people who have died / population = percentage that have died of Covid-19. Example: As of May 1, 23,430 people are estimated to have died out of a total population of 8,398,748 in New York City.  

    23,430/8,398,748= 0.28% x 100, 000 = 279 deaths per 100,000 population.  

 

Death rate provides information on the daily deaths attributed to Covid-19 and the impact of the disease, and as reported by the World Health Organisation the SARS-CoV-2 is fatal in about 3.4% of reported cases. However, monitoring the infection rate have proved to be difficult as people that did not display any symptoms may have not been counted accurately.