There are a few oddities specific to the YEARS protocol precluding universal recommendation as is. Most important, D-dimer results were routinely available prior to risk stratification. This meant clinicians had access to the D-dimer result when assessing the patient as “PE is most likely diagnosis.” It is naive to expect foreknowledge of the D-dimer result did not influence their risk stratification, introducing potentially detrimental effects on internal validity and certainly on generalizability.

At the least, these prospective results, along with the retrospective and observational series, support revisiting our thresholds for D-dimer. In patients for whom PE is not likely, it is probably reasonable practice to consider D-dimer results below 1,000 ng/mL as properly further decreasing the likelihood of PE. Overtesting and overdiagnosis of PE have long been recognized as problematic, and applying even this simplest additional layer of Bayesian reasoning to testing for PE will help our patients by decreasing the costs and harms from testing without a disproportionate increase in harms from missed PE.

References

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