Assessing the Relationship Between Life Events and Internet Addiction Disorder Among Adolescents and College Students: A Protocol for Systematic Review and Meta-analysis

The increasing number of adolescents and college students who overuse the Internet is a global problem, brought a series of physical and mental harm to them. Systematic and standardized clinical treatment plan has not yet been formed, early intervention of its inuencing factors, However, may help to reduce the symptoms of over-dependence to a certain extent. In this study, we will synthesize the present studies to evaluate the relationship and the mediating factors between life events and internet addiction disorder among adolescents and college students. is high-quality to and data of


Abstract Background
The increasing number of adolescents and college students who overuse the Internet is a global problem, brought a series of physical and mental harm to them. Systematic and standardized clinical treatment plan has not yet been formed, early intervention of its in uencing factors, However, may help to reduce the symptoms of over-dependence to a certain extent. In this study, we will synthesize the present studies to evaluate the relationship and the mediating factors between life events and internet addiction disorder among adolescents and college students.

Methods
From inception to 25 March 2020, and contains the following databases: China National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM), China Science and Technology Journal Database (VIP), Wan Fang Data, PubMed, Embase, The Cochrane Library, and Web of Science, MEDLINE. All observational studies will be included. No restriction on gender, race, or nation. Two reviewers (JW and YT) will independently conduct study selection, data extraction, and study quality assessment, any discrepancies will be settled by a third author (WP). Study quality will be assessed by the Newcastle-Ottawa Scale. The main outcome is several scales include YDQ, CIAS-R, IAT, ASLEC, LES and other highquality scales on IAD and life events. We will use Review Manager 5.3 software to assess bias risk and data synthesis of each study.

Discussion
The ndings of this study may provide a helpful reference for the intervention of Internet addiction disorder among adolescents and college students.
Systematic review registration CRD42020177316 Background Internet Addiction Disorder (IAD) refers to the uncontrolled impulsive use of the Internet under the in uence of no addictive substances, which lead to obvious physical, psychological and social impairment [1]. In recent years, with the increasing popularity of the Internet and the rapid development of network technology, the excessive dependence of adolescents and college students on the Internet has become a widely concerned of social and family [2]. A recent research indicated that the prevalence percentage among adolescents in China was close to 10%, which is higher than that observed in the World (6.0%) [3]. Some previous studies showed that IAD severely impaired the attention, memory, cognitive control and other functions of adolescents and college students, moreover, IAD is also a major risk factor for students' academic imbalances, impaired social functioning, behavioral disorders, anxiety, depression and other psychological problems [4][5][6][7][8][9].
Life events is de ned in the literature as "the major failure or success encountered by the individual in real life, or the events that caused the individual to have a greater emotional response and involve lifestyle changes" [10,11]. As a common psychological and social stressor, life events is one of the important psychological stress factors affecting individual health especially negative events [12]. Accumulating studies suggested that negative life events may increase the risk of individual suicide, school problem behaviors, criminal behaviors, addictive behaviors, etc. [13][14][15][16].
Is there a relationship between negative events and IAD and which mediating model is optimal? In recent years, some researchers have conducted in-depth research on this. Xiao et al. showed that there were signi cant differences in the total scores of life events and factors among college students with different degrees of IAD, and those with higher scores of IAD were signi cantly higher in the total scores and factors of life events scale than lower scores [12]. In addition, many clinicians found that adolescents and college students who experience more negative life events are more likely to have IAD [10,12,[17][18][19][20]. However, Mei et al. found that there was no signi cant difference in the average score of life events between Internet addicts and non-addicts [21]. Besides, there are many mediating models of IAD and life events. Some researchers thought it should be Self-disclosure play a leading role, some thought it was Coping style, Counterfactual thinking and Resilience, some researchers even thought there were multiple effects between life events and IAD [20,[22][23][24][25].
From the above, there is no consensus on the relationship and mediating factors that play the main role between IAD and life events on published researchers. Therefore, we will conduct a meta-analysis to ascertain the relationship and the mediating factors between life events and IAD among adolescents and college students.

Objectives
The aim of this study is to arrangement and analysis the published data to determine the relationship and mediating factors between life events and IAD among adolescents and college students. In order to provide a new reference for the clinical intervention of IAD. we will focus on the following questions: 1)What is the relationship between life events and IAD?
2)What kinds of events will be the most risk factors?
3)Which factor plays the main mediating role?

Methods
The protocol of this systematic review (SR) will be reported following the Preferred Reporting Items for Systematic Review and Meta-analysis Protocol (PRISMA-P)2015 [26] guidelines. See S1 Table for

Participants
Participants who were diagnosed with IAD (Between the ages of 13 and 25) will be included. There will be no restriction on gender, race, or nation.

Interventions
This study is an observational study without any intervention.

Comparators
Since most included studies are observational, there may not be any control group/comparison group at all.

Outcome measurements
The main outcome will be the scales associated with clinical and psychopathological measures. IAD was measured by young diagnostic questionnaire for IAD (YDQ) [27], Chinese Internet Addiction Scale Revision (CIAS-R) [28], Internet Addiction Test (IAT) [1], Life events was measured by Adolescent Self-rating Life Events Checklist (ASLEC) [29], The Life Experiences Survey (LES) [30]and other high quality scales on IAD and Life events. As the scales used in different studies are different, the results will be comprehensively analyzed based on the nal included literature.

Search strategy
Database searches We will search the following databases from inception to 25 March 2020: China National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM), China Science and Technology Journal Database (VIP), Wan Fang Data, PubMed, Embase, The Cochrane Library, and Web of Science, MEDLINE. In addition to the electronic database, we will also search for grey literature and related literature listed in the bibliography to ensure the integrity of the included studies.

Search terms
Our search strategy was based on the following combination terms: (internet OR online gaming OR internet gaming OR game) AND (addiction OR pathological OR problem OR excessive OR disorder OR overuse) AND (event OR life events OR experiences). The search strategy of each databases will be adapted accordingly. The search terms in Web of Science is as follows.

Studies selection
Citations from each search will be managed by EndNote X9 and duplicates will be removed. Two reviewers (WJ and TY) will independently screen titles and abstracts after removing duplicates to select inclusion of potentially eligible trials. Then, they will download the full texts of all eligible studies and further independently examine the full text. Any discrepancies will be resolved through negotiation. If necessary, it will be resolved by a third reviewer (PW). The study program is carried out according to the PRISMA ow chart, which is displayed in Fig. 1.

Data extraction
Two reviewers will independently extract data with a prede ned data extraction form which include the following information: rst author, publication year, country, journal, sample size, mean age of the sample, gender distribution, race, number, method of diagnosing IAD, measures used, assessment measures, results and key conclusions, mediating factors.
The extracted data will be entered into Microsoft Excel by two reviewers independently. Two reviewers will cross check the included studies, and the differences will be resolved by consensus or discussion with a third reviewer (HQH).

Risk of bias (quality) assessment
In this study, we will use the modi ed version of the Newcastle-Ottawa Quality Assessment Form (NOS) [31]to evaluate the included studies. The Newcastle-Ottawa Quality Assessment Form assess each study according to three domains and eight items [32]. The domains are as follows: selection of the study groups, comparability of the groups and ascertainment of exposure/ outcome. The scale adopts the semi-quantitative principle of star system, and graded into the three categories, with a full score of 9 stars. Among them, those with more than 7 stars are de ned as high-quality research, 4-6 stars are medium-quality and less than or equal to 3 stars as low-quality research [31]. Any study that meets the inclusion criteria will be included, but we will operate sensitivity analysis their impacts on the study.

Data synthesis and analysis
In this study, Revman5.3 [33] will be used to perform all meta-analyses. We will use I 2 index to measure heterogeneity among studies [34]. If the values of I 2 ≤ 50% show acceptable homogeneity, a xed-effects model will be used. However, we will employ a random-effects model if the values of I 2 > 50% where signi cant heterogeneity exists. Besides, we also plan to perform meta-analysis to analyze the pooled outcome data when the nal acceptable homogeneity has been identi ed. Otherwise, we will conduct subgroup analysis to check the potential causes of obvious heterogeneity among eligible studies. If possible, we will perform a narrative summary when meta-analysis is not possible. If the number of studies allows further strati cation, we plan to do the following subgroup analyses: sex, gender, study size, Geography, etc.
Publication bias we will use funnel plot to estimate the publication biases if su cient studies are included. If bias is identi ed, we will use subgroup analysis or meta-regression analysis to explore its possible in uencing factors. Finally, sensitivity analysis will be conducted to verify the robustness of merged outcome results by removing low-quality studies.

Ethics and dissemination
This protocol of systematic review does not require ethical approval because it will be based on published researches. The results will be published in peer-reviewed scienti c journals according to the PRISMA guidelines.

Discussion
Previous studies have found that IAD is closely related to negative events experienced by individuals [17,20,35,36]. In addition, healthy adaptation, punishment, interpersonal relationship and learning pressure factors are the dimensions that predict a high degree of IAD in life events [16,18,30,37]. There are many studies on the factors that play a speci c intermediary effect between life events and IAD, but there is no uniform conclusion. Moreover, most of the above studies have limitations, such as small sample size, strong regional effect and others. To adolescents and college students as the object, this study will evaluate the dimensions of life events that are more valuable for predicting IAD, as well as the speci c factors that play an intermediary role. The ndings of this study may provide a useful reference for guiding adolescents and college students to understand themselves in real life better, prevent IAD and realize their self-worth.