A detailed statistical analysis of the performance of CO-RADS and CT-severity score in the diagnosis of COVID-19 pneumonia compared to RT-PCR test: a prospective cohort study

Egyptian Journal of Radiology and Nuclear Medicine

Table 7 The sensitivity and specificity of CT when categorized and analyzed according to CO-RADS and CTSS, respectively, compared to the sensitivity and specificity of RT-PCR test

*High suspected patients’ group	*Low suspected patients` group	CT CO-RADS categories	^CTSS	^{RT-PCR test positive results}	^{RT-PCR test negative results}
4	34	CO-RADS 1 N = 38	0.9 ± 0.4	N = 2	N = 36
2	9	CO-RADS 2 N = 11	4 ± 2	N = 1	N = 10
29	6	CO-RADS 3 N = 35	10.2 ± 2	N = 14	N = 21
20	3	CO-RADS 4 N = 23	14 ± 6	N = 19	N = 4
33	4	CO-RADS 5 N = 37	19 ± 7	N = 28	N = 9
CT sensitivity	93.18%
CT specificity	76.8%
PPV of CT	55.41%
NPV of CT	45.18%
CT accuracy	86.8%
CT positive rate	66%
RT-PCR test sensitivity	64.2%
RT-PCR test specificity	93.9%
PPV of RT-PCR test	41.13%
NPV of RT-PCR test	59.51%
RT-PCR test accuracy	74.3%
RT-PCR test positive rate	44.4%

CTSS: CT severity score, NPV: negative predictive value, PPV: positive predictive value, RT-PCR test: Real-time reverse transcription–polymerase chain reaction
*The patients were divided in two groups based on high or low clinical suspicion according to CDC COVID-19 case definition