The aim of this study was to develop a self-administered scale based on the special features of smartphone. The reliability and validity of the Smartphone Addiction Inventory (SPAI) was demonstrated. A total of 283 participants were recruited from Dec. 2012 to Jul. 2013 to complete a set of questionnaires, including a 26-item SPAI modified from the Chinese Internet Addiction Scale and phantom vibration and ringing syndrome questionnaire. There were 260 males and 23 females, with ages 22.9±2.0 years. Exploratory factor analysis, internal-consistency test, test-retest, and correlation analysis were conducted to verify the reliability and validity of the SPAI. Correlations between each subscale and phantom vibration and ringing were also explored. Exploratory factor analysis yielded four factors: compulsive behavior, functional impairment, withdrawal and tolerance. Test–retest reliabilities (intraclass correlations = 0.74–0.91) and internal consistency (Cronbach's α = 0.94) were all satisfactory. The four subscales had moderate to high correlations (0.56–0.78), but had no or very low correlation to phantom vibration/ringing syndrome. This study provides evidence that the SPAI is a valid and reliable, self-administered screening tool to investigate smartphone addiction. Phantom vibration and ringing might be independent entities of smartphone addiction.

The aim of this study was to investigate the risk factors of smartphone addiction in high school students.A total of 880 adolescents were recruited from a vocational high school in Taiwan in January 2014 to complete a set of questionnaires, including the 10-item Smartphone Addiction Inventory, Chen Internet Addiction Scale, and a survey of content and patterns of personal smartphone use. Of those recruited, 689 students (646 male) aged 14 to 21 and who owned a smartphone completed the questionnaire. Multiple linear regression models were used to determine the variables associated with smartphone addiction.Smartphone gaming and frequent smartphone use were associated with smartphone addiction. Furthermore, both the smartphone gaming-predominant and gaming with multiple-applications groups showed a similar association with smartphone addiction. Gender, duration of owning a smartphone, and substance use were not associated with smartphone addiction.Our findings suggest that smartphone use patterns should be part of specific measures to prevent and intervene in cases of excessive smartphone use.

Background and aims: Internet gaming disorder (IGD) is an increasingly important topic and has been included in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) research criteria. This study aims to validate the Chinese version of the Ten-Item Internet Gaming Disorder Test (IGDT-10), a self-reported questionnaire based on DSM-5 IGD criteria, and to estimate the prevalence of IGD in adolescents. Methods: The IGDT-10 was translated to Chinese as a 10-item questionnaire rated on a 3-point Likert scale to evaluate the symptoms of IGD. Overall, 8,110 students from grade four to senior high who played Internet games were administered the questionnaire. In addition, 76 senior high-school students were interviewed using DSM-5 criteria to determine the optimal cut-off point that ensures adequate sensitivity, specificity, and diagnostic accuracy. The cut-off point was determined using the Youden’s index and optimal diagnostic accuracy. Results: The Chinese version of the IGDT-10 showed good internal consistency (Cronbach’s α = .85) and adequate diagnostic efficiency (area under the curve = 0.810). Through interviews, the optimal cut-off point was determined to be five out of the nine criteria (Youden’s index: 42.1%, diagnostic accuracy: 86.8%, sensitivity: 43.8%, and specificity: 98.3%). In this study, the prevalence of IGD among adolescent gamers was 3.1%. Conclusion: Findings evidence the validity and diagnostic accuracy of the IGDT-10 in the assessment of IGD.