Study design and population
We examined the number of death by suicide and suicide attempts in metropolitan France for the last 10 years (2009-2018) in French national databases provided by Santé Publique France. As the national public health agency, Santé Publique France has full legal access to national health databases (7).
More specifically, the data on deaths by suicide and suicide attempts were provided on a daily basis, from two databases:
- A database for suicide attempts, with data from January 1, 2009, to December 31, 2018, grouped by department (French local administrative division). These data corresponded to all medical visits (consultations, hospitalizations, emergencies) for suicide attempts over the period of the study. These data were collected from the database using PMSI-MCO (Programme de Médicalisation du Système d’Information – Médecine Chirurgie Obstétrique) coding and correspond to ICD-10 codes X60 to X84 (detailed below).
- Deaths by suicide were extracted from the death certificates database (CepiDc-Inserm, medical research institute in France). These were daily data, by departments, over a period from January 1, 2009, to December 31, 2015. Data after this date were not available at the time of the extraction for analysis.
For both databases (suicide attempts and deaths by suicide), Santé publique France also provided information concerning age (5-year age groups), gender, and the method used for suicide in 10 categories: drug self-intoxication (X60, X61, X62, X63, X64), intoxication by other products (alcohol, solvents, gas, pesticides, chemicals) (X65, X66, X67, X68, X69), self-inflicted injury by exposure to smoke, flames and gas (X75, X76, X77), self-inflicted injury by sharp object (X78, X79), self-inflicted injury by hanging, strangulation, suffocation (X70), self-inflicted injury by jumping (X80), self-inflicted injury by firearm (X72, X73, X74), self-inflicted injury by drowning or submersion (X71), self-inflicted injury by intentional collision (X81, X82), self-inflicted injury by unspecified means (X83, X84).
These data were merged with a third database from PMSI-MCO 2009-2018 providing the psychiatric disorders that had been identified at the time suicide attempts. These psychiatric diagnoses were coded according to ICD-10 criteria, and correspond to the following diagnoses : organic, including symptomatic, mental disorders (F00, F01, F02, F03, F04, F05, F06, F07, F09), mental and behavioral disorders due to psychoactive substance use (F10, F11, F12, F13, F14 ,F15, F16, F17, F18, F19), psychotic disorders (F20 (schizophrenia), F21, F22, F23, F24, F25, F28, F29), bipolar disorders (F30, F31), depressive disorders (F32, F33, F34, F38, F39), neurotic, stress-related and somatoform disorders (F40, F41, F42, F43, F44, F45, F48), eating disorders (F50) and disorders of adult personality and behavior (F60, F61, F62, F63, F64, F65, F66, F68, F69). In France, the CepiDC death certificate database is not sufficiently informative about comorbid psychiatric disorders at the moment of the death, and psychological autopsies are rare and only performed on request. Therefore, the associations with psychiatric comorbidities will only be studied in this work with suicide attempts, which are coded by psychiatrists .
We calculated a rate of suicide and suicide attempts per department and year, using the number of inhabitants per department and year provided on a database available on the INSEE website (https://www.insee.fr ; National institute for statistics and economic studies).
Daily data were grouped by week or month. Suicide rates were calculated by department per 100,000 inhabitants, per day, week and month. We made a statistical description of the different variables. We statistically examined the seasonal effect of deaths by suicide and suicide attempts by using the cosinor model, which captures a seasonal pattern using a sinusoidal wave (analysis made with the “Season” R package, made by Barnett & Dobson).
Analyses were carried out using R Studio software, version 1.1.463.