The Pooled Prevalence and Influential Factors of Non-Suicidal Self-Injury in Non-Clinical Samples During the COVID-19 Outbreak: A Meta-Analysis.

Background: COVID-19 has had an enormous impact on the mental health of people around the world, particularly adolescents. Non-suicidal self-injury (NSSI) is one of the most prominent and dangerous behaviors associated with suicide. However, few meta-analyses of the NSSI prevalence have ever been conducted since the COVID-19 outbreak. Here, we conducted a meta-analysis to estimate the pooled prevalence and elucidate the influencing factors for NSSI. Methods: We searched PubMed, Web of Science, Embase, APA PsycINFO, CNKI and Wanfang Database for relevant literature published before April 2022. Pooled prevalence and 95 % confidence interval (CI) were used to assess NSSI prevalence. Subgroup and meta-regression analyses were performed to clarify the potential influencing factors. Results: A total of 15 studies with 24,055 participants were eventually included. The results showed that the pooled overall prevalence of NSSI among overall samples during the COVID-19 pandemic was 22.5 % (95 % CI: 17.2 % to 28.9 %). Subgroup and meta-regression analyses revealed that the crucial influencing factors for NSSI included gender, age, regional distribution, and suicidal ideation. Specifically, the NSSI prevalence among adolescents and adults during the pandemic was 32.40 % and 15.70 %, respectively. Most importantly, gender is a significant influencing factor for NSSI among adolescents. Conclusions: The pooled prevalence of NSSI during the COVID-19 outbreak has surged to alarming heights, especially among adolescents. The prevalence of NSSI may be influenced by complex factors such as gender and age. Therefore, it is critical to pay attention to NSSI behaviors in the adolescent population, particularly male adolescents who appear to be susceptible.