Paediatric suicide data

Swedish children and adolescents who, at the age of 10-17 (excl. 0-9 year), died by suicide during the 44-year period 1980-2023 (ICD-diagnoses: E950-E959, X60-X84). Dataset version 2 does not contain deaths with undetermined intent (ICD-diagnoses: E980-E989, Y10-Y34). Version 1 did, however.

Ecological study design, where the Swedish pediatric population (boys and girls aged 10-17 and 10-14) is analyzed as a time series. The purpose of the analysis is to detect trends and patterns over several years. All cases are dead individuals, observed in a retrospective manner through vital records. The design is not truly longitudinal, as humans only die once, and cannot be followed up.

This is an aggregated dataset. It uses data from two other datasets which are not linked, but inferred by year. The primary source is the Swedish cause of death register, reflecting cause-of-death certificates at the individual-level (one death per row). These cause-of-death data were originally provided by the National Board of Social Affairs and Health, requested by the National Centre for Suicide Research and Prevention, NASP Sweden (data delivery on 2024-September-26; Socialstyrelsen Dnr.: 122437/2023). The original file contained high-quality, detailed, nation-wide, individual-level data, restricted to maximum 44 years (1980-2023) and restricted to only contain deaths related to suicide and deaths with undetermined intent. The individual-level data is referred to as the “Original Data file”; it requires special permission to use and will not be shared. The shared dataset is referred to as the “Raw Dataset” because planned analyses only rely on annually aggregated data that allows for independent replication. At the first step, all death counts were extracted for age groups 0-9, 10-14, and 10-17, respectively (note, however, that the youngest age group only comprises <5 suicides and are omitted from the timeseries dataset). Secondly, the data was aggregated by year but stratified by sex (Both Sexes, Males, Females). The resulting annual counts appear in the dataset as 9 columns with 264 rows (44 years * 6 groups). The second data source was used to extract and calculate the male and female mid-year population counts for the same groups. Mid-year counts are derived from end-year population counts (e.g., 1979+1980/2 = Mid-year count for 1980). The population data is public domain, and free access was provided by Statistics Sweden (SCB, 2025). Population data appears in separate columns in the dataset, so that suicide rates (e.g., per 100 000 capita) can be modelled with or without them, and if necessary, model suicide rates with heteroscedastic standard errors (e.g., should it turn out that the population sizes for males and females differ a lot).

The dataset comprises a total of N=878 deaths over 44 years, so 5% (i.e. 44/878=0,05) of the total deaths are expected to occur in any given year (approximately 20 deaths, in absolute terms). However, if many of the years deviate, and deviates a lot from this percentage, this might indicate that a significant time trend has been observed – or that two or more linear time trends are observed (e.g. a V-shaped curve connected with 1 joinpoint at the bottom of the V). This assumes that boys and girls follow the same time trend, which might not be true. But if any gender has many years deviating from its expected percentage, this can imply a time*sex interaction (if not pure data noise).

Individual-level data are typically based on forensic cause-of-death certificates, processed and curated by Socialstyrelsen (the National Board of Health and Welfare). Through an application to Socialstyrelsen, individual-level data concerning suicides (and suspected suicides) were accessed and examined. Relevant cases were selected and aggregated on a national and annual basis. Only the aggregated dataset was subject to formal analysis.

The dataset covers Sweden on a national level. More granular data is not presented due to ethical considerations. Swedes who die abroad are still tied to their Swedish home-municipality (where they officially resided while being abroad). People who die by suicide whilst living or visiting Sweden, without being registered residents, might create bias. Such cases have not always been included in the cause-of-death register, but are more likely to become included since 2012, but with a certain delay.