Catalonia Suicide Risk Code Epidemiology (CSRC-Epi) study: protocol for a population-representative nested case-control study of suicide attempts in Catalonia, Spain.

INTRODUCTION: Suicide attempts represent an important public health burden. Centralised electronic health record (EHR) systems have high potential to provide suicide attempt surveillance, to inform public health action aimed at reducing risk for suicide attempt in the population, and to provide data-driven clinical decision support for suicide risk assessment across healthcare settings. To exploit this potential, we designed the Catalonia Suicide Risk Code Epidemiology (CSRC-Epi) study. Using centralised EHR data from the entire public healthcare system of Catalonia, Spain, the CSRC-Epi study aims to estimate reliable suicide attempt incidence rates, identify suicide attempt risk factors and develop validated suicide attempt risk prediction tools. METHODS AND ANALYSIS: The CSRC-Epi study is registry-based study, specifically, a two-stage exposure-enriched nested case-control study of suicide attempts during the period 2014-2019 in Catalonia, Spain. The primary study outcome consists of first and repeat attempts during the observation period. Cases will come from a case register linked to a suicide attempt surveillance programme, which offers in-depth psychiatric evaluations to all Catalan residents who present to clinical care with any suspected risk for suicide. Predictor variables will come from centralised EHR systems representing all relevant healthcare settings. The study's sampling frame will be constructed using population-representative administrative lists of Catalan residents. Inverse probability weights will restore representativeness of the original population. Analysis will include the calculation of age-standardised and sex-standardised suicide attempt incidence rates. Logistic regression will identify suicide attempt risk factors on the individual level (ie, relative risk) and the population level (ie, population attributable risk proportions). Machine learning techniques will be used to develop suicide attempt risk prediction tools. ETHICS AND DISSEMINATION: This protocol is approved by the Parc de Salut Mar Clinical Research Ethics Committee (2017/7431/I). Dissemination will include peer-reviewed scientific publications, scientific reports for hospital and government authorities, and updated clinical guidelines. TRIAL REGISTRATION NUMBER: NCT04235127.

Measures of frequency used in cohorts studies to evaluate the suicidal behaviour in young people (12-26 years): A systematic review. / Medidas de frecuencia utilizadas en estudios de cohortes para evaluar el comportamiento suicida en jóvenes (12-26 años): una revisión sistemática.

INTRODUCTION: A priority for the WHO by 2020 is to have reduced the rates of suicide; they indicate difficulties in giving precise estimations due to a wide variety of factors, which include aspects related to the statistical measurements themselves of suicidal behaviour. The proportion of deaths from suicide is 8.5% among young people between 15-29 years of age. OBJECTIVE: To review the methodology used to express the frequency of suicidal behaviour in young people and to describe the methodological characteristics of the studies reviewed. METHOD: A systematic review of longitudinal studies registered on PROSPERO. The extracted information included the following: year of publication, journal, population size, sample, country, design, age, percentage of men, follow-up time and losses, suicidal behaviour, risk factors, ethical aspects, fundamentally, evaluating the measures of frequency used. RESULTS: Eighty-two articles were selected from 37,793 documents. None of the studies define the measure of frequency used for suicidal behaviour, there are currently up to 9 different ways of measuring it. The populations are students or the general population (66%), birth cohorts (16%) and specific groups. Follow-up was from 24 weeks to 30 years. Only 24.1% of the studies took ethical aspects into consideration. CONCLUSIONS: Researchers must make an effort to reach an agreement on the measures of frequency used in suicidal behaviour studies, as the methodological and terminological variability currently used impedes making any comparisons between different studies or understanding the real dimension of the problem.