Diagnostic delay of pulmonary embolism in primary and secondary care: a retrospective cohort study.

Background Delayed diagnosis of pulmonary embolism (PE) is common because symptoms can be non-specific. The few studies that have investigated diagnostic delay have not taken into account the role of primary care physicians in the diagnostic process. Aim To document and quantify the stages of diagnostic delay of PE and to identify clinical factors associated with this delay. Design and setting A retrospective cohort study conducted in Zwolle and its surroundings in the Netherlands. Method Primary and secondary care records of all patients diagnosed with PE between January 2008 and December 2009 were reviewed for dates of symptom onset, date of presentation and diagnosis, and for clinical findings. Relationships between delay and clinical parameters were tested using multivariate regression analysis. Results The 261 patients enrolled in the study had an average total delay of 8.6 days. Patient delay (4.2 days average) and delay in primary care (3.9 days) were the major contributors to this delay. Chest pain (odds ratio [OR] 0.51, 95% confidence interval [CI] = 0.28 to 0.92, P = 0.03) and symptoms of deep venous thrombosis (calf pain) (OR 0.49, 95% CI = 0.24 to 0.98, P = 0.05) were associated with an early diagnosis. Patient delay was shorter in patients with chest pain (OR 0.49, 95% CI = 0.25 to 0.95, P = 0.03) and longer in patients with dyspnoea (OR 2.95, 95% CI = 0.99 to 8.85, P = 0.05). In primary care, chest pain (OR 0.37, 95% CI = 0.17 to 0.84, P = 0.02) and rales (OR 0.22, 95% CI = 0.06 to 0.83, P = 0.03) were associated with an early referral, whereas comorbidity led to a delayed referral. Conclusion This study shows that the diagnostic delay of PE is substantial, especially patient delay and delay in primary care. There is room to reduce this delay by increasing the awareness of both patients and GPs. Further research is needed on clinical factors that raise suspicion of PE in primary care.