Occurence of Internet addiction in a general population sample: A Latent Class Analysis

May combine two claims.

Based on participants aged 14-24, the cut-off of 28 estimated Internet addiction prevalence at 3.8% (95% CI 3.0-4.6) overall, 4.5% (95% CI 3.3-6.0) in females, and 3.0% (95% CI 2.2-4.3) in males.

“Based on participants aged 14-24, Internet addiction occurred in 3.8% (CI 3.0-4.6) in total, 4.5% (CI 3.36.0) in females, and 3.0% (CI 2.2-4.3) in males.”

May combine two claims.

Using the recommended CIUS cut-off of 28, estimated Internet addiction prevalence was 1.5% (95% CI 1.3-1.7) for the entire sample, 1.3% (95% CI 1.0-1.7) for females, and 1.7% (95% CI 1.3-2.1) for males.

“the recommended cut-off (28) for the CIUS was used to estimate occurrence of Internet addiction resulting in 1.5% (CI 1.3-1.7) for the entire sample, 1.3% (CI 1.0-1.7) for females, and 1.7% (CI 1.3-2.1) for males.”

May combine two claims.

In the current sample, the CIUS had a Cronbach's alpha of 0.87, indicating good internal consistency.

“In the current sample, α was 0.87 which approves the good internal consistency of this instrument.”

May combine two claims.

Age, migration background, and unemployment were significantly related to Internet addiction in a logistic regression.

“Age, migration background and unemployment were significantly related with Internet addiction”

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Based on participants aged 14-16, the cut-off of 28 estimated Internet addiction prevalence at 6.3% (95% CI 4.6-8.4) overall, 8.6% (95% CI 5.5-13.0) in females, and 4.1% (95% CI 2.6-6.3) in males.

“Based on participants aged 14-16, Internet addiction occurred in 6.3% (CI 4.6-8.4) in total, 8.6% (CI 5.5-13.0) among females, and 4.1% (CI 2.6-6.3) among males.”

May combine two claims.

More males than females were in class 6, but this was not statistically significant in the regression model (OR 1.53; 95% CI 0.99-2.35).

“More males than females were in class 6, however this was not statistically significant in the regression model (OR 1.53; 0.99-2.35).”

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Classes 5 and 6 had higher CIUS scores, more online time, and less social participation.

“class 5 and 6 showing higher CIUS scores, more time spent in the Internet and less social participation.”

Classified as probably not a substantial claim.

An 8-class solution was not considered because a group of n = 8 emerged as part of the n = 118 group from the 7-class solution.

“An 8-class solution was not considered because a group of n = 8 emerged as a part of the group of n = 118 from the 7-class solution.”

May combine two claims.

In younger age groups, the proportions of both class 5 and class 6 were higher.

“In younger age groups, proportions of both groups are higher.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Of the total sample of 15,023 participants, 8,132 reported using the Internet for private purposes for at least 1 hour on a typical weekday or at least 1 hour on a weekend day.

“Of the total sample of 15,023 participants, 8,132 reported using the Internet for private purposes at least 1 h on a typical weekday or at least 1 h on a day at the weekend.”

May combine two claims.

Female class-6 members used online games less often as their main Internet activity, but this difference was not statistically significant (7.2% vs. 33.6%, p = 0.057).

“female class-6 members used online games less often, however this was only a tendency and not statistically significant (7.2 vs. 33.6%; χ 2 = 3.79; d.f. = 1; design d.f. = 48; p = 0.057).”

May combine two claims.

Lower BIC values and higher entropy measures were observed as the number of classes increased.

“Lower BIC values and higher entropy measures (both as desired) can be found with the increasing number of classes.”

May combine two claims.

In the youngest group (14-16), proportions were highest for females, although not statistically significant.

“in the youngest group (14-16) of our study, proportions were highest for females, although not statistically significant.”

May combine two claims.

In younger age groups, proportions are higher, with up to 4% for Internet addiction in 14- to 16-year-olds.

“In younger age groups, proportions are - as expected - higher with up to 4% for Internet addiction in the 14- to 16-year-old participants.”

May combine two claims.

This withdrawal effect was observed in both groups but was strongest in class 6.

“This could be observed in both groups but was strongest in class 6 representing Internet addiction.”

May combine two claims.

A 6-class solution showed the best fit and included two classes that differed in variables related to problematic and addictive Internet use compared to the other groups.

“A 6-class solution showed the best fit and included 2 classes that differed in variables that are related to problematic and addictive Internet use compared to the other groups.”

May combine two claims.

A second group showed the second highest CIUS scores and time spent online, the second lowest social participation, and the lowest mean age.

“A second group shows the second highest values in CIUS scores and time spent in the Internet, the second lowest scores in social participation and the lowest mean age.”

May combine two claims.

One group showed the highest CIUS scores and time spent online, and the lowest social participation.

“One group showed highest rates in CIUS scores and time spent in the Internet, whereas social participation was lowest.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Female participants showed a tendency to use online games less often as their main Internet activity.

“female participants showed a tendency to use less often online games as their main activity on the Internet.”

May combine two claims.

Most studies used convenience samples, and in those studies the chance of being included was likely confounded with the problem behaviour being measured.

“The majority of studies have used convenience samples consisting of non-representative subgroups such as can be found in online surveys. In these studies, probability of study inclusion was obviously likely to be confounded with the problem behaviour to be measured.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Regional variation cannot explain the very large differences in prevalence estimates across studies.

“regional differences cannot account for the immense difference in prevalence rates that have been found.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The DSM-5 proposed criteria for Internet addiction are limited to Internet gaming.

“However, in DSM-5, the proposed criteria are restricted to Internet gaming.”

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Probably not a substantial claim: may not pass S3 (load-bearing).

Reported prevalence rates of Internet addiction across studies range from 1% to 14%.

“Rates range from 1 to 14% [7]”

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Compulsive Internet use or Internet addiction is widely asserted to exist and is listed in DSM-5 as a condition needing further study.

“the existence of compulsive Internet use or Internet addiction is widely claimed and included as a condition for further research in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) [1, 2]”

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May combine two claims.

Class 5 represents at-risk Internet use and class 6 represents Internet addiction.

“Data can be interpreted as class 5 representing at-risk use and class 6 Internet addiction.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The CIUS has 14 items and was developed to assess five core criteria for Internet addiction: salience, withdrawal, loss of control, conflict, and coping with unpleasant mood.

“It consists of 14 items and was developed to assess the following 5 core criteria for Internet addiction: salience, withdrawal, loss of control, conflict and coping with unpleasant mood.”

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Classified as probably not a substantial claim.

The present study conducted a latent class analysis in a large representative general population sample.

“the present study performed a LCA in a large representative general population sample”

May combine two claims.

The CIUS has shown good validity and Cronbach's alpha reliability between 0.88 and 0.90.

“The questionnaire showed good validity and a Cronbach's α as measure of reliability ranging from 0.88 to 0.90 [18, 19]”

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Probably not a substantial claim: may not pass S3 (load-bearing).

A previous latent class analysis in two large Dutch school-based samples found that a 6-class model had the best fit.

“In two large school-based samples, respondents filled out the Compulsive Internet Use Scale (CIUS) [19] , a 14-item questionnaire covering core criteria of problematic Internet use. A LCA revealed a 6-class model to have the best fit.”

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Classified as probably not a substantial claim. May combine two claims.

The previous latent class analysis results are limited to adolescents and to online gaming.

“However, results are restricted to adolescents and to online gaming.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The CIUS was selected because psychometric data for it are available from representative samples.

“This instrument was chosen because data on its psychometric performance in representative samples are available [19]”

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

Both general population studies of Internet addiction used diagnostic measures that have not been sufficiently validated.

“Both general population studies suffer from diagnostic measures that have not been sufficiently validated.”

Classified as probably not a substantial claim.

Data used to define Internet addiction come from clinical settings and may not cover the full range of characteristics present in the general population.

“Data to define Internet addiction are derived from clinical settings but may not cover the whole spectrum of characteristics found in the general population.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The landline sample was drawn as a clustered and stratified sample with probability proportional to size and implicit stratification to support representativeness.

“For the landline telephone survey a clustered and stratified sample was drawn. At the first sampling stage, 53 sample points (52 municipalities, Berlin was represented by two sample points) were selected based on a 'probability proportional to size' procedure. Implicit stratification ensures a representative selection of German federal states, administrative districts and counties.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The mobile-only sample participation rate was 56.6%, yielding 1,001 respondents.

“56.6% (1,001 respondents) participated in the interview.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Among participants assessed with the CIUS, 3.2% did not answer all items, and missing values were replaced by mean values when at least 8 items had been answered.

“Of those, 3.2% did not answer to all CIUS items. In the majority of these cases the participants had only one (2.5%) or two (0.4%) missing values. Further, 0.3% did not answer between 3 and 10 CIUS items. A minimum number of 8 items answered was defined and missing values were replaced by mean values.”

Probably not a substantial claim: may not pass S3 (load-bearing).

In that previous latent class analysis, two classes had characteristics making it very likely that participants were heavy users or had problems with online gaming.

“According to the data, 2 of these classes showed characteristics that made it very likely that participants were experiencing heavy use or problems with online gaming”

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Probably not a substantial claim: may not pass S3 (load-bearing).

The CIUS items were translated into German using translation and back-translation.

“The CIUS items were transformed into German by procedures of translation and back-translation.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The 20-item Internet Addiction Test is the most widely used questionnaire for Internet addiction.

“The most widely used questionnaire is the 20-item Internet Addiction Test (IAT) [14]”

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The mobile-only sample used random selection of nationwide cell phone numbers and screened in only those not reachable by landline.

“In the mobile-only sample, a random selection of nationwide cell phone numbers was used and a screening to include only those who could not be reached via landline telephone was performed.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Tao and colleagues define a minimum of 6 hours per day of Internet use as required for a diagnosis of Internet addiction.

“Tao et al. [7] define a minimum amount of 6 h/day spent in the Internet to fulfil the diagnosis of Internet addiction.”

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The landline sample participation rate was 52.4%, yielding 14,022 respondents.

“52.4% (14,022 respondents) participated in the interview.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The telephone survey used a German landline sample plus an additional mobile-only sample to cover people reachable only by cellular phone.

“The survey was based on a German landline telephone sample and an additional mobile-only sample to cover the growing percentage of individuals that are only accessible via cellular phone numbers.”

Classified as probably not a substantial claim. May combine two claims.

The Internet Addiction Test was developed in clinical settings, and its psychometric properties in general population samples are unclear.

“This scale has been developed in clinical settings and psychometric properties for general population samples are unclear.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The social participation instrument had good test-retest reliability with a kappa of 0.70 based on dichotomous results.

“Good test-retest reliability was found with a κ of 0.70 based on dichotomous results [22]”

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Classified as probably not a substantial claim.

The study provides characteristics that can help further define Internet addiction as a relatively new disorder.

“provides characteristics to further define this rather new disorder.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Social participation was assessed with a standardized instrument asking about participation in 13 activity domains during the previous 12 months.

“It was assessed with a standardized instrument by asking if respondents had taken part in activities in 13 domains during the last 12 months [22]”

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May combine two claims.

The authors state their study is the largest representative general-population study so far to estimate how common Internet addiction is and to describe associated features.

“This is the largest representative general population study that aimed to quantify the occurrence of Internet addiction and describe related characteristics so far.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Generalized trust was assessed with the item 'Generally, you can trust other people' using four answer options.

“Generalized trust to other people was assessed with the following item: 'Generally, you can trust other people' with the answer formats 'Do not agree at all' , 'Do not agree' , ' Agree' , and 'Completely agree' [21]”

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Classified as probably not a substantial claim.

The CIUS has shown a stable one-factor solution across time and different samples.

“A stable one-factor solution was found across time and different samples [19]”

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

In that previous study, the dependent-user group made up 3% of the sample and about 1.5% of all children aged 13-16 in the Netherlands.

“This latter group constituted 3% of the sample and about 1.5% of all children aged 13-16 years in the Netherlands.”

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Classified as probably not a substantial claim.

A CIUS cut-off score of 28 was suggested by the instrument's developers.

“a cut-off score of 28 was suggested from the developers of this instrument [19]”

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Classified as probably not a substantial claim.

The CIUS is a questionnaire that covers well-accepted signs of problematic Internet use.

“These classes were based on the CIUS, a questionnaire which covers well-accepted signs of problematic Internet use.”

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Probably not a substantial claim: may not pass S3 (load-bearing).

A clear advantage of this study is its large and representative sample size.

“A clear advantage of this study is the large and representative sample size.”

Probably not a substantial claim: may not pass S2 (checkable).

The inclusion of mobile-only participants is of special importance.

“Therefore, the inclusion of mobile-only participants is of special importance.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

It is not very likely that the inclusion filter resulted in biased findings, but it cannot be fully ruled out.

“It is not very likely that this filter resulted in biased findings, however it cannot be fully ruled out.”

Classified as probably not a substantial claim.

Proposed criteria for Internet addiction by Tao et al. include a course criterion requiring at least 3 months of duration and 6 hours of Internet non-business usage per day.

“Proposed criteria for Internet addiction by Tao et al. [7] include a course criterion requiring at least 3 months of duration and 6 h of Internet non-business usage per day.”

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Probably not a substantial claim: may not pass S3 (load-bearing).

The CIUS might not cover all relevant aspects to specify Internet addiction.

“Another possible shortcoming might be that the CIUS which served as the basis for the LCA might not cover all relevant aspects to specify Internet addiction.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The CIUS includes salience, withdrawal, loss of control, conflict, and coping with unpleasant mood, which resemble current suggestions for classifying Internet use disorders.

“salience, withdrawal, loss of control, conflict and coping with unpleasant mood are included and resemble current suggestions for classifying Internet use disorders.”

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Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

The LCA approach is currently a viable method given that no consensus on criteria to define Internet addiction or problematic Internet use is available.

“the LCA approach is currently a viable method considering that no consensus on criteria to define Internet addiction or problematic Internet use is available.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Use and misuse of mobile phones is prevalent in adolescents.

“use and misuse of mobile phones is prevalent in adolescents [28]”

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May combine two claims.

Using the suggested cut-off of 28 results in a rate of 1.5% positive cases and strengthens the solution.

“using the suggested cut-off of 28 for CIUS might serve as another indicator. This results in a rate of 1.5% positive cases and strengthens our solution.”