Peer Review #2 of "Mobile phone addiction and non-suicidal self-injury among adolescents in China (v0.2)"

Background: Non-suicidal self-injury (NSSI) has recently widely discussed.Independently, mobile phone addiction has also attracted academic attention.A few research have examined the correlation between the two.However, there is inadequate knowledge to characterize this relationship altogether.This study further explores the correlation between mobile phone addiction and NSSI, specifically repeated and severe NSSI.Method: A population-based cross-sectional survey was conducted among 2,719 adolescents in Lincang, Yunnan.The mobile phone addiction index (MPAI) and the Modified Adolescents Self-Harm Survey (MASHS) were administered in combination.The connection between the MPAI and NSSI, as well as both repeated and severe NSSI, was studied using univariate and multivariate logistic regression models.(The copyright holders have permitted the authors to use the MPAI and the MASHS)Results: The prevalence of NSSI was 47.11% (95% CI: 36.2%-58.0%),and the detection rate of mobile phone addiction was 11.11% (95% CI: 6.7%-18.0%).The prevalence of NSSI among those with mobile phone addiction was 4.280 times (95% CI: 3.480-5.266)that of respondents not exhibiting mobile phone addiction.In addition, all subscales of the MPAI, except for the feeling anxious and lost subscale, were positively correlated with NSSI.Risk factors, represented by odds ratios, of repeated NSSI with the inability to control cravings subscale, the feeling anxious and lost subscale, and the withdrawal subscale was 1.052 (95% CI: 1.032, 1.072), 1.028 (95% CI: 1.006-1.051),and 1.048 (95 % CI: 1.019-1.078)respectively.Risk factors of these same three subscales for severe NSSI, had odds ratios of 1.048 (95% CI: 1.029-1.068),1.033 (95% CI: 1.009-1.057),and 1.045 (95% CI: 1.018-1.073). Conclusion:Mobile phone addiction was shown to be a risk factor for NSSI in adolescents.Individuals with high scores on the unable to manage cravings subscale, the withdrawal subscale, and the feeling anxious and lost subscale were more prone to experience repeated and severe NSSI.As a result,early assessment using the MPAI to determine the need for intervention can contribute to the prediction and prevention of NSSI.