Coronary calcium score improves the estimation for pretest probability of obstructive coronary artery disease and avoids unnecessary testing in individuals at low extreme of traditional risk factor burden: validation and comparison of CONFIRM score and genders extended model

Table 3 Reclassification table using PTP categories < 15%, 15–85%, and > 85% (Individuals with 0 RF)

PTP category based on GEM	PTP category based on CONFIRM score				Reclassification^a		NRI^b	p value for NRI
PTP category based on GEM	Low	Medium	High	Total	Up	Down
Negative individuals					8.59%	32.10%	29.85%	< 0.0001
Low	300	260	3	563
Medium	66	196	6	268
High	3	3	1	7
Total	369	459	10	838
Positive individuals^c					17.63%	11.29%
Low	11	15	5	31
Medium	6	235	21	262
High	1	57	12	70
Total	18	307	38	363

NRI net reclassification improvement; other abbreviations as in Table 1
^aIndividuals was reclassified by GEM and was compared to CONFIRM score
^bNRI = [P(Up|Positive)- P(Down|Positive)]-[P(Up|Negative)- P(Down|Negative)]
^cPositive individuals was defined as those had at least one lesion with ≥50% diameter stenosis or any non-assessable segments due to severe calcification on CCTA