**1. Introduction**

Internet pornography use (IPU) is a sexual behavior [1], corresponding to the use of internet to engage in various gratifying sexual activities also known as online pornography use or cybersex [2–4]. It comprises a variety of online sexual activities (OSAs), including watching pornography, online pornography exchange, engaging in sex chats, using sex webcams, searching for sexual partners, or engaging in sexual role playing, among which stands the watching pornography, which is the most popular activity [5]. According to the past findings, engaging in IPU sometimes derives various negative consequences, such as financial, legal, occupational, and relationship trouble or personal problems [6]. Feelings of loss of control and persistent use despite these adverse outcomes constitute compulsive cybersex or problematic IPU. To date, no consensus exists regarding the conceptualization and diagnosis of problematic IPU. For instance, numerous terms have been used to describe the phenomenon (e.g., internet sex addiction [7,8], problematic online sexual activities [9], cybersex addiction [10], and problematic internet pornography use [6]). Although these concepts are slightly different, they all comprise three crucial components: the medium (the internet), the content (sexual behavior), and the problematic use (the compulsive behavior). Regardless of the debate, it is now acknowledged that excessive involvement in IPU or cybersex may become dysfunctional and associated

with addiction symptoms (e.g., loss of control, compulsive use). Considering these inconsistent terms sharing crucial components, problematic IPU may be regarded as a subtypes of problematic internet use from a classification perspective, which may help advance clinical and research efforts into its prevalence and impact.

Nevertheless, evidence regarding the problematic IPU is inconsistent, due to the heterogeneity of assessment tool. The fundamental reason is that the definition and diagnostic criteria of problematic IPU is still unclear. In order to address these conceptual ambiguities, researchers have developed several scales that measure different aspects of pornography use [11]. Some briefer scales are more convenient to administer, but they underscore the self-perceived addiction (e.g., Cyber-Pornography Use Inventory-9). Some of these scales have been designed to assess the motivations underlying pornography use among hypersexual men (e.g., Pornography Consumption Inventory) [12]. Some scales fail to capture the different aspects of problematic IPU and focus solely on specific dimensions (e.g., the Pornography Craving Questionnaire, PCQ). Additionally, some globally accessible websites host the Cybersex Addiction Test, Sexaholics Anonymity Test, Sex Addicts Anonymous, and Sexual Addiction Screening Test, which assess difficulties in exercising self-control, its negative consequences, and the social problems that are associated with sexual activities. Furthermore, assessing IPU, using measures of sexual addiction, entails a few challenges. Specifically, these assessments may not be able to capture the characteristics of the activities (e.g., chat-based cybersex, sexual video games that cannot be played offline) and symptoms (e.g., separation from reality due to immersion in the virtual world that are unique to IPU. To address this gap in the literature and conduct further research in this domain, assessments with strong psychometric properties are much needed [5,7].

Several scales of problematic IPU are available to researchers and clinicians. Indeed, a recent meta-analysis identified 22 psychometric instruments that assess problematic pornography use [11]. Otherwise, most of the studies that have been conducted during the past decade had used self-developed items and a few of these measures have been subsequently revalidated [4,5,13]. Therefore, it is difficult to compare the results of different studies because there is a lack of concordance in the assessments that have been used. In order to select suitable tools for comparison from the existing scales, a systematic review was conducted. The following terms and their derivatives were used in multiple combinations: (Cybersex\* OR internet porn\* OR hypersex\*) AND (addict\* OR compulsiv\* OR problem\*) AND (assessment OR scale OR instrument OR measure\*), to identify relevant studies in order to address the questions related to assessment and available screening questionnaires. The selection criteria of the literature search were limited to articles focusing specifically on cybersex and/or internet pornography consumption and dysfunctional cybersex, and also describe the development and adaptation of self-reported psychometric instruments that assesses at least one aspect of problematic pornography use. Finally, we found a total of 27 instruments on assess the problematic IPU (cybersex). Through the systematic review process conducted, we decided to retain three scales that were developed to measure problematic pornography use, even if not all of the three scales were specifically designed to measure internet pornography, as a large majority of participants used online pornography, and the developers of these scales suggested that they could be used to measure problematic IPU [14,15], additionally we replaced "pornography" into "internet pornography" in the Chinese version. We selected these three scales for the following reasons: (1) they include fewer items and are thus easily administered measures, (2) all of them cover the core characteristics of IPU, such as loss control, (3) they are grounded in addiction components such as impaired control, conflict, salience [11], (4) they are applicable within the Chinese culture [16–19], and (5) they display strong test-retest (i.e., two weeks) reliability; consequently, these three previously validated scales were identified for further examination. First, the Short Internet Addiction Test Adapted to OSAs (s-IAT-sex), which has demonstrated satisfactory psychometric properties [9]. However, this scale has been validated only among men [5], and a large number of studies have shown that there are substantial gender differences in IPU [18,20,21]. Second, the Problematic Pornography Use Scale (PPUS) [15], which has been validated using a large sample; unfortunately, however, a valid cutoff score has not been specified for this measure. Third,

the Problematic Pornography Consumption Scale (PPCS); this scale is founded upon the theoretical framework of Griffiths's components model of addiction [22]. All three scales include strong internal consistency and a valid factorial structure, which has been supported by the results of confirmatory factor analysis (CFA) [9,14,15,19]. Nevertheless, it is difficult to compare the findings of studies that have used these scales because they entail different factor structures. Therefore, it is necessary to select reliable indicators and methods, and identify the most accurate instrument.

In order to effectively compare different scales, a unifying and reliable standard should first be established. The Brief Pornography Screener (BPS), which is a screening tool that measures loss of self-control, overuse of problematic pornography use, may be useful in identifying individuals who are at risk for problematic pornography use or can serve as a proxy measure [23]. Kraus et al., who developed the BPS, have proposed that the diagnostic criteria for compulsive sexual behavior (CSB) should be included in the new International Classification of Diseases (ICD-11) [24], and this proposal has been accepted. According to the upcoming ICD-11's diagnostic criteria for impulse control disorder [25], patterns of failure to control intense sexual impulses or urges and the resultant repetitive sexual behaviors are considered to be the characteristic features of the disorder. The BPS considers compulsive pornography to be the core component of problematic pornography use. Moreover, the BPS has been used with different samples, and it has demonstrated satisfactory psychometric properties among American and Polish pornography users [26]. Many past studies have used the BPS to identify pornography addicts. Furthermore, it has also been used to ascertain the severity of problematic pornography use among men who seek pharmacologic or psychological treatment as a result of their loss of control over their sexual behaviors [27–29]. Therefore, in this study, the BPS scores were used as the reference standard against which the sensitivity and specificity of the three aforementioned scales were ascertained.

Several recent reviews have focused specifically on the conceptualization and assessment of problematic pornography use [4,11,30,31]. Some reviews have briefly summarized and commented on the included instruments [5], whereas others have evaluated their ability to assess the core components of problematic pornography use [11]. However, no past study has compared the different scales and identified the most accurate measure of problematic pornography use using a same standard or indicator. Measures of problematic IPU are heterogeneous, and each scale focuses on a different aspect of problematic IPU. Furthermore, because these scales have not been extensively validated, it is difficult to compare the findings of the studies that have used them. In addition, the sensitivity of the different scales that assess problematic IPU have not been adequately compared. Therefore, in the present study, a QUAN→QUAL mixed-methods design was conducted, including (1) using quantitative methods to identify a scale with a higher sensitivity index from three selected scales (PPCS, PPUS, s-IAT-sex) for assessing problematic IPU. Moreover, the duration of usage, frequency of engagement in OSAs, sexual compulsivity, and pornography cravings were used to examine the criterion validity of the assessments. Subsequently, (2) qualitative interviews were conducted with volunteers and therapists who have serviced the individuals in trouble of problematic IPU to further examine the appropriateness of the "more accurate" scale from the service providers' perspectives, whereby the qualitative part helps to evaluate and interpret the results obtained from the main quantitative study.

#### **2. The Quantitative Part: A Comparison of the Three Retained Scales**

#### *2.1. Materials and Methods*

#### 2.1.1. Sample

The study sample consisted of 560 men and 412 women, and the mean age of the sample was 24.8 years [*standard deviation (SD)* = 7.2 years; range = 18–48 years]. The group comparisons of the demographic characteristics of the three study samples can be inferred from Table 1.



<sup>1</sup> PPCS = Problematic Pornography Consumption Scale, <sup>2</sup> PPUS = Problematic Pornography Use Scale, <sup>3</sup> s-IAT-sex = Short Internet Addiction Test Adapted to Online Sexual Activities, <sup>4</sup> SD = standard deviation.

#### 2.1.2. Instruments

#### Three Main IPU Measurements

PPUS. The PPUS is a 12-item self-report scale that assesses four dimensions of IPU [15]: distress and functional problems, excessive use, difficulties in self-control, and IPU to escape or avoid negative emotions. In the Chinese version of the assessment, the term "pornography," which was used in the original scale, was modified as "internet pornography" in all instances (e.g., "I spend too much time being involved in thoughts about internet pornography"). The participants were required to indicate the frequency with which they had engaged in IPU during the past 6 months on a six-point scale that ranged from 0 (never) to 5 (all the time). Higher scores were indicative of a greater severity of engagement in IPU. The Cronbach's alpha of the total scale was 0.95 in this study.

PPCS. The PPCS was used to measure problematic IPU [14]. Responses were recorded on the following 7-point scale: 1 = never, 2 = rarely, 3 = occasionally, 4 = sometimes, 5 = often, 6 = very often, 7 = all the time. PPCS consists of 18 items, and assesses the six core components of addiction: salience, mood modification, conflict, tolerance, relapse, and withdrawal. Each factor is measured by three items (e.g., "I felt that I had to watch more and more internet porn for satisfaction" is an item of measure "tolerance"); the Cronbach's alphas of the aforementioned six factors were 0.77, 0.84, 0.71, 0.78, 0.86, and 0.86, respectively, in the study. The Cronbach's alpha of the total PPCS was 0.96. A cutoff score of 76 was used to ascertain normal and problematic use; specifically, scores that were greater than 76 were indicative of problematic use.

s-IAT-sex. Responses to each of the 12 items of the s-IAT-sex are recorded on a five-point scale that ranges from 1 (never) to 5 (always) [9]. The scale consists of two dimensions. The first factor assesses poor self-control and difficulties in reducing the amount of time that is spent online (six items, e.g., "How often do you find that you stay on Internet sex sites longer than you intended?"), whereas the second factor measures the functional impairments that are associated with engagement in cybersex (six items, e.g., "How often do you feel depressed, moody, or nervous when you are offline, which

goes away once you are back on internet sex sites?"). The composite score, which can be computed by summing the individual item scores, can range from 12 to 60; higher scores are indicative of greater problems. The internal consistency (Cronbach's alpha) coefficients of the total scale and first and second factors were 0.89, 0.77, and 0.88, respectively, in this study.

#### Criterion Validity Questionnaires

*PCQ*. This 12-item questionnaire is a unidimensional assessment [32,33]. The following are a few sample items: "If the situation permitted, I would watch pornography right now" and "If I were to watch pornography right now, I would have difficulty stopping." The respondents were required to indicate how strongly they agreed with each item using the following seven response options (presented without numerals): "completely disagree," "somewhat disagree," "disagree a little," "neither agree nor disagree," "agree a little," "somewhat agree," and "completely agree." Higher scores are indicative of a greater craving for pornography. The Cronbach's alpha of this scale was 0.92 in the current study. The instructions of the PCQ present a craving-for-pornography vignette, which requires the respondent to imagine that they are alone in their room and seated in front of their computer and that they have a strong urge to watch their favorite type of pornography.

The Sexual Compulsivity Scale (SCS). The extent to which participants exhibit the characteristics of compulsive pornography use was assessed using the 10-item SCS that has been developed by Kalichman et al. [34]. Responses were recorded on a four-point rating scale (1 = not at all like me, 2 = slightly like me, 3 = mainly like me, 4 = very much like me, e.g., "I have to struggle to control my sexual thoughts and behavior"). In this study, the Cronbach's alpha of this scale was 0.86.

Questionnaire of OSAs. Thirteen items were used to measure participants' use of the internet for the following purposes: (1) viewing sexual explicit materials (SEM), (2) seeking sexual partners, (3) cybersex, and (4) flirting and sexual relationship maintenance [35]. Viewing SEM was assessed using five items (e.g., visiting erotic/pornographic websites, viewing and downloading erotic/pornographic videos from the internet, reading erotic/pornographic material online), each of which required responses to be rated on a nine-point scale that ranged from 1 (never) to 9 (at least once a day). The other three subscales assessed frequency using a nine-point scale that ranged from 1 (0 times) to 9 (20 or more times). Two items measured the frequency with which the respondents had sought sexual partners as well as the number of sexual partners that they had sought and found online. The frequency of engagement in cybersex was assessed using four items (e.g., masturbating or viewing strangers masturbating in front of a webcam, describing sexual fantasies either through texts or orally). Internet use for the purposes of flirting and sexual relationship maintenance was measured using two items. The Cronbach's alpha of the entire scale was 0.88 in the study. Higher scores were indicative of more frequent engagement in OSAs.

Additional Questions about IPU. In addition to items that assessed demographic characteristics, a few questions that were related to IPU were also posed to the participants. After providing them with a clear definition of internet pornography, the participants were asked to indicate their age of first exposure to pornography and the duration of time that they typically spent watching internet pornography every week.

#### The Reference Standard—BPS

The BPS, which has been developed by Kraus et al. [26], was used to assess pornography use during the past 6 months. This five-item assessment uses a three-point rating scale (0 = never, 1 = occasionally, 2 = always, e.g., "You find it difficult to resist strong urges to use sexually explicit material."); a cutoff score of 4 was used to detect problematic pornography use (absolute range = 0–10). Higher scores are indicative of more problematic pornography use. The Cronbach's alpha of the BPS was 0.84.

#### 2.1.3. Procedure

This online study was conducted through a popular Chinese survey website, namely, Wenjuanxing (www.sojump.com). Adult members of the website received an email with a link that redirected them to the survey website and a brief introduction to our survey. This brief introduction informed the recipients that they were eligible for participation if they had engaged in IPU during the past 6 months (e.g., reading online pornographic content, browsing pornographic websites, sharing/watching pornographic videos or pictures, interacting and flirting with others) and were interested in participating in the survey. A total of 972 valid responses were collected from participants from 110 cities in 28 of the 34 provinces/regions in China (i.e., identified using the internet protocol addresses). As expected, all participants obtained scores that were equal to or greater than 14 on the measure of OSAs (the lowest possible score is 13, and it indicates no prior IPU); this indicated that all of them had engaged in at least one OSA during the past 6 months. Three highly homogeneous samples were required to respond to the three measures of problematic IPU, namely, the PPCS, PPUS, and s-IAT-sex, respectively. Each sample also completed the aforementioned mentioned assessments against which their criterion validity was to be examined. This study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the Ethics Committee of the Department of Psychology, Fuzhou University (date of approval, 7 April 2019).

#### *2.2. Analysis*

Statistical analyses were conducted using SPSS 19.0 (IBM, Armonk, NY, USA) and Mplus version 7 [36]. Item-total correlations were computed to identify items that functioned poorly. CFA was used to test the factor structures of the scales of interest. Maximum likelihood estimation with the Satorra-Bentler correction was used to determine the fit between the data and the factor structures. Model fit was tested by inspecting the following indices: root mean square error of approximation (RMSEA; good: ≤0.06, acceptable: ≤0.08), comparative fit index (CFI; good: ≥0.95, acceptable: ≥0.90), and Tucker-Lewis index (TLI; good: ≥0.95, acceptable: ≥0.90). The reliability of the scales was assessed by computing Cronbach's alpha coefficients.

To identify possible groups of at-risk pornography users, latent profile analysis (LPA) was used. LPA was conducted using the original dimensions of each scale as explicit variables, and different groups of individuals with problematic IPU were successively divided into two to four categories for model fitting estimation. Sensitivity was defined as the proportion of persons with positive symptoms (as detected by the BPS) and members of the at-risk group (identified through LPA), whereas specificity was defined as the proportion of persons with negative symptoms and the nonproblematic group [37].
