Validation of the Swedish National Inpatient Register for the diagnosis of pulmonary embolism in 2005.

The Swedish National Inpatient Register (NPR) has near-complete coverage of in-hospital admissions and ICD codes in Sweden. Acute pulmonary embolism (PE) is a serious condition presenting challenges regarding diagnosis, treatment, and follow-up. Here we aimed to validate the accuracy of acute PE diagnosis in the NPR, investigational findings, antithrombotic treatment, and follow-up of PE patients in Sweden. From a nation-wide cohort of all patients with in-hospital diagnoses of acute PE (ICD-10-SE codes I26.0-I26.9) in 2005 ( = 5793), we selected those from two Swedish regions for thorough manual review of hospital records. We identified 599 patients with PE diagnoses according to the ICD-10 coding system. We excluded 58 patients with admissions related to previous PE (47; 8%) or incorrect ICD codes (11; 2%), leaving 501 patients with probable PE diagnoses. We confirmed the diagnosis in 441 (79%) cases, which was based on imaging (435 patients; 73%) or autopsy (6; 1%). In the remaining 60 (11%) cases, the PE diagnosis was based on clinical findings and can therefore not be confirmed. Of the surviving patients with PE, 231 (47%) were offered follow-up within 6 months after the acute event. At follow-up, 67 patients (29%) had symptoms requiring clinical attention (dyspnoea or reduced general condition). The Swedish NPR showed acceptable accuracy for PE diagnosis, and could be reliably used for register-based research regarding acute PE.