 Using the cutoff adjusted to age cutoff for D-Dimer test positivity equals age multiplied by ten, in microgL, the figure was as follows. D-Dimer levels were below the adjusted cutoff in 6151712 patients 35.9, number needed to test 2.8. This represented a statistically significant 20.1 increase in the number of patients in whom the D-Dimer test was considered as negative, p0.0002. Of these 615 patients, 5 had PE during initial workup 0.8, 95 percent confidence interval 0.4 to 1.9. 