Non-suicidal self-injury behaviours among adolescents in Beijing: protocol for an epidemiological and qualitative exploration

Abstract

Introduction: Non-suicidal self-injurious behaviour (NSSI) is defined as purposeful self-injury without the intention to die. NSSI has become an important threat to public health among teenagers globally, imposing considerable costs on individuals, families and society. It reflects poor emotional regulation and serves as an early warning sign for suicidal ideation and behaviour. The purpose of this study is to look at the prevalence of NSSI and the risk factors related to it in Beijing's adolescent population.

Methods and analysis: Epidemiological surveys and qualitative interviews will both be used in this study. First, a cross-sectional epidemiological survey with stratified sampling will assess the prevalence, risk factors and variables associated with NSSI among adolescents in Beijing. The survey will include a sample size of at least 1415 adolescents. The significance of emotional control, social support and mental health in NSSI conduct will then be investigated through qualitative interviews. This part of the study will use a phenomenological qualitative research approach, with the sample size determined by data saturation, typically around 10 participants, but flexible due to the large sample from the epidemiological survey. In order to investigate the prevalence of NSSI, statistical analysis of correlation, descriptive statistics and regression analysis with multiple variables will be used to analyse the survey data using SPSS V.27.0 and Excel 2003. NVivo V.12 software will be used to code the qualitative data, and thematic analysis and word frequency will be used to find connections between the various NSSI experiences.

Ethics and dissemination: The Guang'anmen Hospital Ethics Committee of the China Academy of Chinese Medical Sciences has given its approval to the project (no. 2023-259-KY). Participants will provide both verbal and written informed consent prior to participation, with legal guardians signing for the qualitative part of the study. Participants will be informed of their right to withdraw from the study at any time without affecting their clinical care. Results will be shared through academic journals, conferences and public health platforms to raise awareness of NSSI and inform related policy development.

Trial registration number: ChiCTR2400085968.

Keywords: adolescents; epidemiologic studies; mental health; qualitative research; suicide & self-harm.

Figure 1. Study flow chart. This flow chart shows the steps of the study. Participants will be recruited from middle and high school campuses, as well as psychiatric outpatient clinics. First, participants must meet the inclusion/exclusion criteria for the epidemiological survey and give informed consent to join the cross-sectional survey (n≥1415). After completing the survey, a group of adolescents who have engaged in NSSI will be selected for qualitative interviews (n≥10). These interviews will also require participants to meet the inclusion/exclusion criteria and sign informed consent forms. Finally, the data from both the surveys and interviews will be compiled and analysed statistically.

Figure 2. Study timeline.