Identifying chronic thromboembolic pulmonary hypertension (CTEPH) through French national hospital database (PMSI)

Abstract

Background: CTEPH, a rare pulmonary vascular disease, is often misdiagnosed due to nonspecific symptoms. Orphanet estimates the prevalence as 30 cases/million; however a recent review suggested 45 cases/million in France [Gall 2017]. We aimed at estimating the frequency of CTEPH using PMSI. Aims: To estimate the number of patients hospitalised for CTEPH in France in 2015. Methods: As ICD-10 coding for pulmonary hypertension (PH) does not uniquely document CTEPH, a case ascertainment algorithm to identify CTEPH hospitalizations was developed in close collaboration with an expert committee, using a two-step process (refinement and validation), based on matched data from PMSI and hospital medical records from 2 competence centres (Paris, Lyon). Results: The best-performing algorithm (specificity 95%, sensitivity 70%, negative predictive value 99%, positive predictive value 41%) consisted of ≥1 PH diagnosis during one year (2015) and any of the following criteria over a 6-year period (2009-2015): (i) CTEPH surgery (ii) admission for PH and pulmonary embolism (PE) (iii) PE followed by hospitalisation in competence centre then in reference centre (iv) history of PE and right heart catheterisation. Patients with conditions suggestive of pulmonary arterial hypertension were excluded. When applied to all PMSI, a total of 3,138 patients hospitalised for CTEPH was estimated in 2015 (47 cases/million). Conclusions: Our method provides an estimate of over 3,000 hospitalised patients with CTEPH in France in 2015 (~67 million inhabitants). Assuming patients are hospitalized at least once a year, this may represent the disease prevalence. This study confirms the heavy burden of CTEPH.