Sensitivity of nasal and oropharyngeal swabs in diagnosing COVID-19 in hospitalised patients

Khan, K. S. , McLellan, M., Torpiano, G., Ng, S. and Mahmud, S. (2020) Sensitivity of nasal and oropharyngeal swabs in diagnosing COVID-19 in hospitalised patients. Annals of Public Health Reports, 4(1), pp. 136-140. (doi: 10.36959/856/509)

Abstract

Background: To evaluate the sensitivity of nasal and oropharyngeal swabs in diagnosing COVID-19 in hospitalised patients and comparing patient factors and admission investigations to the swab result. Methods: Multicentre retrospective cohort study of all COVID-19 swab positive patients who were in-patients on 9th April 2020. Electronic case notes were analyzed for baseline characteristics including; age, gender, co-morbidities, admission blood tests and swab results. The results of each consecutive swab for COVID-19 was analysed for each patient. The number of swabs required to achieve a positive test was used to assess the sensitivity of the test. Results: Of the 173 patients identified, 108 (62.4%) were males, mean age was 68.4 ± 14.7 years. Commonest co-morbidity was hypertension (50.9%). 152 (87.9%) patients had their first swab positive. Age over 71 years was positively associated (53.3% vs. 23.8%, p = 0.018) and age-adjusted Charlson Comorbidity Index ≤ 2 was negatively associated (25.0% vs. 52.4%, p = 0.009) with the first swab being positive. Admission blood tests and chest X-ray findings did not influence the swab results. Conclusion: The sensitivity of swab for symptomatic and hospitalised patients was higher than previously thought and admission investigations do not predict the result of swab in COVID-19 positive patients.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Khan, Mr Khurram
• Authors: Khan, K. S., McLellan, M., Torpiano, G., Ng, S., and Mahmud, S.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences; College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: Annals of Public Health Reports
• Publisher: Scholars.Direct
• ISSN: 2642-4924
• ISSN (Online): 2642-4924
• Published Online: 31 December 2020
• Copyright Holders: Copyright © 2020 Khan KS, et al.
• First Published: First published in Annals of Public Health Reports 4(1):136-140
• Publisher Policy: Reproduced under a Creative Commons license