TITLE:
Optimum Threshold Estimation of Thorax CT Scan for COVID-19 Diagnosis in a Single Center in Cameroon
AUTHORS:
Anne Esther Njom Nlend, Landry Bonyomo, Serges Abogo, Serges Nga Nomo, Luc Meka, Moise Nna, Beatrice Meva’a, Arsene Brunelle Sandie, Christiane Nsahlai
KEYWORDS:
COVID-19, CT Scan, Lung, Diagnosis
JOURNAL NAME:
Advances in Infectious Diseases,
Vol.13 No.1,
February
8,
2023
ABSTRACT: Objective: To evaluate the lung CT scan as a possible predictive diagnostic method for COVID-19 in the Cameroonian context. Methods: We designed a cross sectional study. Suspected cases of COVID-19 during the first wave at the national social insurance fund (NSIF) hospital were screened with both COVID-19 with lung CT scan and a PCR test. Univariate analysis was performed for sample description and multivariate analysis to assess the correlation between positive results for the PCR and other parameters. We estimated the optimum threshold of sensitivity/specificity, and area under curve using the empirical method and package. Results: A total of 62 suspected COVID-19 cases were recorded, predominantly males (Sex Ratio = 2.2) with a median age of 58.5 (IQR = 19.7). Among our 62 patients, 29 (46.8%) were confirmed COVID-19 cases with positive PCR results. All the patients had a thorax CT scan with a median impairment of 40% (IQR = 20%). The optimum threshold estimate for CT scan for COVID-19 infection diagnosis was 60% (95% CI = 25% - 80%). Overall, the sensitivity and specificity estimates were 0.30 (95% CI = 0.15 - 0.49) and 0.87 (95% CI = 0.70 - 0.96), respectively, leading to an Area Under Curve (AUC) estimate of 0.59 (95% CI = 0.46, 0.71). Conclusion: In this setting, lung CT scan was neither sensitive nor specific to predict COVID-19 disease.