Alternative diagnoses in patients in whom the GP considered the diagnosis of pulmonary embolism.

INTRODUCTION: Pulmonary embolism (PE) often presents with nonspecific symptoms and may be an easily missed diagnosis. When the differential diagnosis includes PE, an empirical list of frequently occurring alternative diagnoses could support the GP in diagnostic decision making. OBJECTIVES: To identify common alternative diagnoses in patients in whom the GP suspected PE but in whom PE could be ruled out. To investigate how the Wells clinical decision rule for PE combined with a point-of-care d-dimer test is associated with these alternative diagnoses. METHODS: Secondary analysis of the Amsterdam Maastricht Utrecht Study on thrombo-Embolism (Amuse-2) study, which validated the Wells PE rule combined with point-of-care d-dimer testing in primary care. All 598 patients had been referred to and diagnosed in secondary care. All diagnostic information was retrieved from the GPs' medical records. RESULTS: In 516 patients without PE, the most frequent alternative diagnoses were nonspecific thoracic pain/dyspnoea (42.6%), pneumonia (13.0%), myalgia (11.8%), asthma/chronic obstructive pulmonary disease (4.8%), panic disorder/hyperventilation (4.1%) and respiratory tract infection (2.3%). Pneumonia occurred almost as frequent as PE. Patients without PE with either a positive Wells rule (>4) or a positive d-dimer test, were more often (odds ratio = 2.1) diagnosed with a clinically relevant disease than patients with a negative Wells rule and negative d-dimer test. CONCLUSION: In primary care patients suspected of PE, the most common clinically relevant diagnosis other than PE was pneumonia. A positive Wells rule or a positive d-dimer test are not only positively associated with PE, but also with a high probability of other clinically relevant disease.

The additional value of the CRP test in patients in whom the primary care physician excluded pulmonary embolism.

BACKGROUND: After excluding pulmonary embolism (PE) with an unlikely Wells-decision rule and a negative D-dimer test, the general practitioner still has to differentiate between clinically relevant and clinically non-relevant diseases accounting for the presented symptoms. A negative D-dimer test makes clinically relevant disease less likely. The C-reactive protein (CRP) test could be of additional value to make this differentiation. OBJECTIVES: To assess whether an unlikely Wells-decision rule in combination with a negative point of care D-dimer test not only can safely exclude PE but also, in combination with a negative CRP-test, any other clinically relevant disease. METHODS: We used data of a prospective study including 598 primary care patients suspected of pulmonary embolism. We included all patients, referred to secondary care for reference testing, with an unlikely Wells-decision rule and a negative point of care D-dimer test. We included 191 patients and imputed the CRP-test results in 60 patients. Alternative diagnoses were divided in clinically relevant diseases and clinically non-relevant diseases. A ROC-curve was constructed to determine the optimal CRP-cut-off. RESULTS: The optimal CRP cut-off value appeared to be 10 mg/l. A total of 116 patients had a CRP < 10 mg/l of whom 12 patients (10%) had a clinically relevant disease. Two patients (2%) needed hospital admission. A total of 75 patients had a CRP ≥ 10 mg/l of whom 32 patients (43%) had a clinically relevant disease. Fifteen patients (20%) were admitted to hospital. CONCLUSION: The CRP-test is enhancing diagnostic decision making in patients in whom the general practitioner excluded PE.