Screening tools commonly include fever, respiratory symptoms (cough, shortness of breath), and epidemiological risk factors.
· The sensitivity and specificity of screening questionnaires depends considerably on the items used in the questionnaire. The limited published literature demonstrates great variability in the performance of different screening tools: sensitivity ranges from 0 – 48.6 – 84.3 – 100%; specificity ranges from 64.8 – 71.3 – 89.6 – 96%).
· The standard WHO symptom checklist performs poorly, with a sensitivity of 48.6%, and specificity of 89.6%. As such, half of individuals who have SARS-CoV-2 present at the time of testing will be missed by the symptom questionnaire (being either asymptomatic or presymptomatic). Depending on the population being screened the prevalence of the virus may vary widely. Given the sensitivity and specificity of the WHO symptom checklist in a population with prevalence ranging from 0.1% to 1% to 10% the positive predictive value (PPV) will be poor, range from 0.4% to 4.8% to 35%, respectively. Furthermore, the performance characteristics of the screening questionnaire may be poorer than reported if used in a setting or time of year when other respiratory viruses with similar symptoms are circulating.
Fick, F; Neudorf, C; Reeder, B; Dalidowicz, M; Mueller, M. What is the sensitivity and specificity of screening checklists and temperature checks for detecting the presence of COVID-19 in individuals? 2020 Apr 28; Document no.: PH042401 RR. In:
COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2020. 20 p. (CEST rapid review report)