Diagnostic Accuracy of D-Dimer Testing and the Revised Geneva Score in the Prediction of Pulmonary Embolism

Figures & data

Table 1 Personal and Clinical Characteristics of the Study Sample

Characteristics	Total (N=2010)
Age (years), mean (SD)	52.6 (20.2)
Sex: Female/Male	1290/720 (1.8)
Clinical characteristics: Age >65 years Previous DVT or PE	595 (29.6) 41 (2.0)
Surgery (under general anesthesia) or fracture of lower limbs within 1 month	138 (6.9)
Active malignant conditions	293 (14.6)
Unilateral lower-limb pain	12 (0.6)
Hemoptysis	14 (0.7)
Heart rate 75–94 beats/min.	1330 (66.2)
Heart rate >95 beats/min.	680 (33.8)
Pain on lower-limb deep venous palpation and unilateral edema	0 (0.0)
Revised Geneva Score (clinical probability)  Geneva Low score (0–3)	747 (37.2)
Geneva Intermediate score (4–10)	1254 (62.4)
Geneva High score (more than 10)	9 (0.4)

Abbreviations: DVT, deep vein thrombosis; PE, pulmonary embolism.

Table 2 Comparison Between Conventional D-Dimer and Age-Adjusted D-Dimer in Accuracy of Prediction of Pulmonary Embolism

	Chest CT Scan
	Positive No.(%)	Negative No.(%)	Total No.(%)
Conventional D-dimer
Abnormal	312 (15.5)	1472 (73.2)	1784 (88.8)
Normal	20 (1.0)	206 (10.2)	226 (11.2)
Total	332 (16.5)	1678 (83.5)	2010
Sensitivity=94%, specificity= 12.3%, PPV=17.5%, NPV= 91.2, kappa=0.009, p=0.001
Age-adjusted D-dimer
Abnormal	308 (15.3)	1422 (70.7)	1730 (86.1)
Normal Total	24 (1.2) 332 (16.5)	256 (12.7) 1678 (83.5)	280 (13.9) 2010
Sensitivity= 92.8%, specificity= 15.3%, PPV= 17.8%, NPV= 91.4%, kappa= 0.030, p<0.001.

Abbreviations: PPV, positive predictive value; NPV, negative predictive value.

Table 3 Performance of D-dimer and Age-Adjusted D-dimer Testing and Their Level of Agreement in the Prediction of Pulmonary Embolism

	Age-Adjusted D-dimer
Conventional D-Dimer	Abnormal		Normal		Total
	n.	PE	n.	PE	n.	PE
Abnormal	976	181	54	4	1030	185 (18.0)
Normal	o	0	98	8	98	8 (8.2)
Total	976	181(18.5)	152	12(7.9)	1128	193 (17.1)

Notes: kappa=0.08, p<0.001.1; Level of agreement, [(976+98)/1128) x 100=95.2%; Agreement on negative cases, [(8+90)/(8+90)] =100%; Agreement on positive cases, [(181+795)/(185+845)]=97.3%; Agreement in Positive CTPA, [(181+8)/198=95.5%; Agreement in negative CTPA, [(795+90)/935]=94.7%.

Abbreviation: PE, pulmonary embolism.

Table 4 Prevalence of Pulmonary Embolism in Patients with Different Revised Geneva Score Categories and Validity of a Cutoff of 5 Revised Geneva Score ≥5 in the Prediction of Pulmonary Embolism

Revised Geneva Score (3 categories)	Chest CT Scan
	Positive no.(%)	Negative no.(%)	Total no.(%)
Low	0 (0.0)	747 (100.0)	747 (37.2)
Intermediate	324(25.8)	930 (74.2)	1254 (62.4)
High	8 (88.9)	1 (11.1)	9 (0.4)
Total	332 (16.5)	1678 (83.5)	2010 (100.0)
Revised Geneva Score (2 categories)	Chest CT Scan
	Positive no.(%)	Negative no.(%)	Total no.(%)
Likely (5 points or more)	332 (100.0)	642 (38.3)	974 (48.5)
Unlikely (<5 points)	0 (0.0)	1036 (61.7)	1036 (51.5)
Total	332	1678	2010

Notes: Sensitivity=100%; specificity= 61.7%; PPV=34.1%; NPV= 100; kappa=0.35, p=<0.001.

Figure 1 Receiver operating characteristic curve of the Revised Geneva Score cutoff for the exclusion of pulmonary embolism. [The cut of point of Revised Geneva score for diagnosis of pulmonary embolism is 5 points. At this point, the sensitivity is 100%, specificity= 61.7%, PPV=34.1%, NPV= 100% and kappa=0.35, p=<0.001].

Table 5 Application of a Clinical Decision Rule and Age-Adjusted D-dimer Threshold for Prediction of PE

Age-Adjusted D-dimer	Revised Geneva Score	No. of Patients	PE Patients No.(%)
Abnormal	Likely (>5points)	860	308 (35.8)
	Unlikely (≤5points)	870	0 (0.0)
Normal	Likely (>5points)	114	24 (21.1)
	Unlikely (≤5points)	166	0 (0.0)

Abbreviation: PE, pulmonary embolism.