Data sources
Data were retrospectively extracted from the French Hospital Medical
Information database (Programme de Médicalisation des Systèmes
d’Information – PMSI). The French PMSI-MCO database covers all
overnight or day hospitalizations in the public and private French
hospitals19. Each hospital stay results in a
production of a standard discharge summary (“Résumé de Sortie
Standardisé” RSS) following inpatient conventional stays, day-hospital
stays or sessions. The RSS is then anonymized to become the RSA
(“Résumé de Sortie Anonyme”). The RSA contains information’s on the
patient characteristics (gender, age, residence code), on the main
diagnosis that led to hospital admission, on the nature of the treatment
and work-up (examinations) carried out, on comorbidities and on
complications. Diagnoses are coded using the International
Classification of Diseases, 10th revision
(ICD-10)20 either as primary- (PD: the condition for
which the patient was hospitalized), related- (RD: any underlying
condition which may have been related to the PD), or significant
associated-diagnoses (SAD: comorbidities or complications which may
affect the course or cost of hospitalization). For each DRG produced,
the hospital receives a payment which amount corresponds to the national
tariff of DRG, intending to cover all hospital expenses.
Since a patient may have several hospital stays during a year, it is
possible to count the number of stays or the total cost of
hospitalization per year, by linking all his hospital stays based on his
patient’s identification number.