Aim
To identify the absolute risk, causes, and factors associated with rehospitalization within 1 year of discharge with a pulmonary embolism (PE).

Methods and results
Using the Danish nationwide registries, all patients admitted with a first-time PE between 2000 and 2020 and discharged alive were included. Subsequent hospitalizations were categorized and crude cumulative incidences were used to estimate the absolute risk (AR) of any rehospitalization and specific causes of rehospitalizations. Risk factors for rehospitalization were investigated using cause specific Cox regression models.

A total of 55 201 patients were identified. The median age of the study population was 70 years (inter quartile range: 59;79), and the most prevalent comorbidities were cancer (29.3%) and ischemic heart disease (12.7%). The 1-year AR of any rehospitalization after discharge with a PE was 48.6% (95% confidence interval (CI); 48.2%–48.8%). The most common cause for being rehospitalized was due to respiratory disease [1-year AR: 9.5% (95% CI: 9.3%–9.8%)], followed by cardiovascular disease [1-year AR: 6.3% (95% CI: 5.9%–6.5%)], cancer [1-year AR: 6.0% (95% CI: 5.8%–6.4%)], venous thromboembolism [1-year AR: 5.2% (95% CI: 5.0%–5.2%)], and symptom diagnoses [1-year AR: 5.2% (95% CI: 5.0%–5.4%)]. Factors that were associated with an increased risk of rehospitalization were cancer, liver disease, chronic obstructive pulmonary disease, chronic kidney disease, and immobilization.

Conclusion
Patients with PE have a high risk of rehospitalization, with almost half of patients being rehospitalized within 1 year. Identification of high-risk patients may help target interventions aiming at reducing the risk of rehospitalization.