From the results of the re-audit, it can be concluded that while the uptake for utilising risk stratification tools such as the Well’s score had improved from 29% to 90.4%, performing and documenting D-dimer results had decreased (83.8% to 69.9%).

11.1% (6/54) requests did not follow the guidelines that recommended that D-dimer be performed in patients who have a Well’s score below 4. It is unknown whether these patients were anticoagulated whilst awaiting CTPA, as recommended by the (NICE guideline, 2023). From these 6 patients, 2 had a positive CTPA.

(British Thoracic Society, 2003) states that when PE is excluded as the cause of the patient’s symptoms, alternative diagnoses can be recognised as the possible cause of symptoms. There was an increase from 46.8% to 71.6% in the alternative diagnoses identified on CTPA for patients who had scans negative for PE.

Although compliance for using the Well’s score when ordering CTPA has increased, there can be an improvement in performing D-dimer for patients in whom PE was calculated to be unlikely. It may be of benefit to consider adding a reminder to the clinician in the questionnaire to anticoagulate the patient if a D-dimer is not able to be obtained within 4 hours for patients who have a Well’s score of less than 4.

There was a greater number of alternative diagnoses suggested on CTPA reports on the re-audit, which may have allowed clinicians to consider the true alternative diagnoses when PE was excluded on the scan.