Unlocking the Secrets of Shopping Addiction: A Deep Dive into the Psychometric Properties of the Bergen Shopping Addiction Scale

Introduction

Shopping is a common and enjoyable activity for many people, but for some, it can become an addictive behavior with serious consequences. Problematic shopping behavior, also known as shopping addiction or compulsive buying, has gained increasing attention in psychological research due to its negative impact on individuals’ financial stability, social relationships, and psychological well-being. To effectively address and manage shopping addiction, it is essential to have reliable and valid assessment tools that can accurately identify individuals at risk. One such tool that has been widely used for assessing shopping addiction is the Bergen Shopping Addiction Scale (BSAS). Developed based on the “components model of addiction,” the BSAS evaluates various aspects of shopping behavior, including preoccupation with shopping, mood modification, conflict, tolerance, withdrawal symptoms, relapse, and problems resulting from excessive shopping. As shopping addiction continues to be a growing concern, understanding the psychometric properties of the BSAS is crucial for clinicians, researchers, and policymakers to develop effective interventions and support strategies. This blog post aims to explore the findings of a recent study that investigated the psychometric properties of the BSAS, including discrimination and difficulty of its items, proposed an optimal raw cut-off score, and examined differential item functioning across gender groups.

Background

Shopping addiction, often termed as problematic shopping behavior (PSB) or compulsive buying, has emerged as a significant behavioral issue affecting a considerable portion of the population. While shopping is a routine activity for most, for some individuals, it escalates into an uncontrollable and compulsive behavior characterized by excessive preoccupation with shopping, mood modification through shopping, conflicts due to shopping, and other addictive behaviors similar to substance dependence (Aboujaoude, 2011; Andreassen et al., 2015).

The terminology surrounding this behavioral issue has evolved over the years, with various terms such as “compulsive spending,” “shopping addiction,” and “shopaholism” being used interchangeably in the literature. Despite the different terms, there is a consensus that problematic shopping behaviors are associated with emotional dysregulation, impulsivity, and an inability to control shopping urges (Christenson et al., 1994).

Recent research has started to conceptualize shopping addiction from an addiction perspective, drawing parallels between shopping addiction and substance addictions. This perspective emphasizes the role of internal factors like distress and external factors like environmental cues in triggering cue reactivity, leading to craving and anticipation of rewards, similar to the mechanisms observed in substance addictions (Gomez et al., 2022; Starcke et al., 2018).

However, the recognition and classification of shopping addiction as a formal diagnosis in psychopathology classification manuals such as the DSM-5 or ICD-11 remain contentious. While some researchers advocate for its inclusion as a distinct behavioral addiction, others argue that it may lead to over-pathologizing common behaviors and activities that individuals find subjectively enjoyable (Kardefelt-Winther et al., 2017; Niedermoser et al., 2021).

Furthermore, the lack of consensus regarding the prevalence rates of shopping addiction and mixed findings on gender differences in prevalence add to the complexity of understanding and addressing this behavioral issue (Andreassen et al., 2018; Georgiadou et al., 2021; Otero-Lopez et al., 2021). Given these challenges, there is a pressing need to evaluate and refine the assessment tools used to measure shopping addiction, such as the Bergen Shopping Addiction Scale (BSAS), to ensure accurate and reliable identification of individuals at risk.

The Bergen Shopping Addiction Scale (BSAS)

The Bergen Shopping Addiction Scale (BSAS) stands out as a prominent tool in the assessment of shopping addiction due to its versatility, promising psychometric performance, and theoretical foundation. Developed by Andreassen et al. (2015), the BSAS is rooted in the “components model of addiction,” which suggests that addictive behaviors share common underlying components regardless of the specific addictive substance or behavior (Griffiths, 2005; Kim & Hodgins, 2018).

The BSAS comprises seven core symptoms that capture the multifaceted nature of shopping addiction:

Excessive preoccupation with shopping (salience)
Shopping to change mood state (mood modification)
Inability to fulfill daily obligations due to shopping (conflict)
Increased amount of shopping over time to obtain satisfaction (tolerance)
Return to excessive shopping after a period of controlled shopping (relapse)
Irritability and frustration in the absence of shopping (withdrawal)
Impaired well-being due to excessive shopping (problems)

Each item of the BSAS is rated on a five-point Likert scale, allowing for a comprehensive assessment of an individual’s shopping behavior and the severity of shopping addiction. The total scores on the BSAS range from 0 to 28, with higher scores indicating a higher risk of shopping addiction.

The BSAS’s theoretical foundation and comprehensive assessment approach make it a valuable tool for researchers and clinicians alike. Its ability to assess both online and in-person shopping behaviors further enhances its applicability in today’s digital age where online shopping has become increasingly prevalent (Uzarska et al., 2019, 2021).

Despite its advantages, there remains a need for further research to evaluate the BSAS’s psychometric properties at the item level using advanced analytical approaches like Item Response Theory (IRT). Such research can provide valuable insights into the discrimination, difficulty, and optimal cut-off scores of the BSAS items, ultimately enhancing the scale’s accuracy and reliability in identifying individuals at risk of shopping addiction.

Methodology

The methodology of the present study offers a robust and systematic approach to investigating the psychometric properties of the Bergen Shopping Addiction Scale (BSAS) and its applicability in assessing shopping addiction.

Participants The study initially recruited 1,097 English-speaking individuals from the general community. After removing 129 invalid responses, the final sample comprised 968 participants aged between 18 and 64 years (Mage = 29.5 years, SD = 9.36), with 32.5% females. This sample size exceeds the suggested minimum for Item Response Theory (IRT) analysis, ensuring sufficient statistical power for the study (Sahin & Anil, 2017).

Instrument The Bergen Shopping Addiction Scale (BSAS) was employed to assess the risk of shopping addiction among participants. The BSAS consists of seven items rated on a five-point Likert scale, with scores ranging from 0 (strongly disagree) to 4 (strongly agree). Each item corresponds to one of the seven core symptoms of shopping addiction as identified by the “components model of addiction” (Andreassen et al., 2015; Griffiths, 2005; Kim & Hodgins, 2018).

Procedure Participants were recruited through email advertisements on the Victoria University student platform and various social media platforms (Twitter, Reddit, Facebook, Instagram) after obtaining approval from the university’s Ethics Committee. Eligible participants were adults aged 18 years and above who voluntarily agreed to participate in the online survey. The survey included demographic questions and the BSAS and was conducted between November 2020 and January 2021.

Statistical Analyses Data analysis followed a sequential process, beginning with IRT models estimated using IRT-PRO (Cai et al., 2011). Model fit was evaluated using traditional fit indices (χ2Loglikelihood), marginal likelihood information statistics (M2), RMSEA, and information criteria (AIC, BIC). Differential Item Functioning (DIF) analyses were conducted to assess item performance across gender groups using Wald tests, with p < 0.05 indicating non-invariance. Finally, BSAS raw scores were converted into risk levels based on Summed Scores Expected a Posteriori (SSEAP [θ|x]) to classify participants exceeding ±2SD as high risk (Cai et al., 2011; Embretson & Reise, 2013).

This rigorous methodology ensures a comprehensive and accurate evaluation of the BSAS’s psychometric properties and its effectiveness in assessing shopping addiction among diverse populations.

Results

The results of the study provide valuable insights into the psychometric properties of the Bergen Shopping Addiction Scale (BSAS) and its effectiveness in assessing shopping addiction.

Descriptive Statistics The descriptive statistics for addictive behaviors, as assessed by the BSAS, revealed varying levels of endorsement across the sample. The internal reliability of the BSAS in the present study was excellent, with Cronbach’s α = 0.88 and McDonald’s ω = 0.88, indicating consistent and reliable measurement of shopping addiction risk among participants.

Item Response Theory (IRT) Analysis The IRT analysis demonstrated differences in the discrimination, difficulty, and precision of the BSAS items. These findings provide a nuanced understanding of each item’s ability to differentiate between individuals with varying levels of shopping addiction and the level at which an item is most likely to be endorsed. Such information is crucial for refining the BSAS and improving its accuracy in assessing shopping addiction severity.

Optimal Raw Cut-off Score Based on the IRT analysis and Summed Scores Expected a Posteriori (SSEAP [θ|x]) conversion, a raw score exceeding 23 out of 28 on the BSAS was identified as indicating a higher risk of shopping addiction. This cut-off score serves as a valuable reference point for clinicians and researchers to categorize individuals into different risk groups and implement appropriate interventions.

Differential Item Functioning (DIF) Across Genders The DIF analysis revealed that most BSAS items functioned similarly across gender groups, with one exception. Item 2 (mood modification) required a higher level of shopping addiction behaviors to be endorsed by males compared to females. This gender difference highlights the importance of considering gender-specific interpretations and thresholds when using the BSAS, ensuring accurate assessments and tailored interventions for both males and females.

Overall, the results of the study enhance our understanding of the BSAS’s psychometric properties and its utility in assessing shopping addiction severity. The identified optimal cut-off score and gender-specific item functioning insights contribute to more accurate and personalized evaluations of shopping addiction risk, facilitating timely interventions and support for individuals at risk.

Discussion

The findings from this study shed light on the psychometric properties of the Bergen Shopping Addiction Scale (BSAS) and its potential implications for the assessment and understanding of shopping addiction.

Interpretation of Findings The IRT analysis revealed valuable insights into the discrimination, difficulty, and precision of the BSAS items, offering a deeper understanding of each item’s ability to differentiate between individuals with varying levels of shopping addiction. The identified optimal raw cut-off score of 23 provides a clear threshold for categorizing individuals into different risk groups, facilitating more targeted interventions and support.

Gender Differences in Item Functioning The observed gender differences in the item functioning of the BSAS highlight the importance of considering gender-specific interpretations and thresholds when assessing shopping addiction. Specifically, the higher level of shopping addiction behaviors required for males to endorse Item 2 (mood modification) compared to females suggests potential differences in shopping addiction presentations and underlying mechanisms between genders. Such insights are crucial for developing gender-sensitive assessment tools and interventions that cater to the unique needs and experiences of both males and females.

Implications for Clinical Practice and Future Research The study’s findings have important implications for clinical practice, research, and policy development. The refined understanding of the BSAS’s psychometric properties and the proposed optimal cut-off score can aid clinicians in accurately identifying individuals at risk of shopping addiction and providing timely interventions. Additionally, the gender-specific item functioning insights underscore the need for gender-sensitive approaches in assessing and treating shopping addiction.

However, it is important to acknowledge the study’s limitations, such as its cross-sectional design and sample characteristics, which may limit the generalizability of the findings. Future research should aim to replicate these findings in larger and more diverse samples and explore additional factors that may influence shopping addiction risk and presentation.

In conclusion, this study contributes to the existing literature by providing a comprehensive evaluation of the BSAS’s psychometric properties and offering valuable insights into its utility in assessing shopping addiction severity. The identified optimal cut-off score and gender-specific item functioning insights enhance the accuracy and personalized nature of shopping addiction assessments, paving the way for more effective interventions and support strategies tailored to individuals’ specific needs.

Conclusion

The comprehensive evaluation of the Bergen Shopping Addiction Scale (BSAS) in this study has provided valuable insights into its psychometric properties and effectiveness in assessing shopping addiction severity.

Key Findings Recap The study’s findings highlighted the BSAS’s strong internal reliability, with an excellent Cronbach’s α of 0.88, indicating consistent and reliable measurement of shopping addiction risk. The Item Response Theory (IRT) analysis further revealed differences in the discrimination, difficulty, and precision of the BSAS items, leading to the identification of an optimal raw cut-off score of 23 out of 28 for categorizing individuals into different risk groups. Additionally, the Differential Item Functioning (DIF) analysis uncovered gender differences in the item functioning of the BSAS, emphasizing the importance of gender-sensitive approaches in shopping addiction assessment and treatment.

Implications and Future Directions These findings have important implications for clinicians, researchers, and policymakers involved in addressing shopping addiction. The identified optimal cut-off score and gender-specific item functioning insights can guide clinicians in accurately identifying individuals at risk of shopping addiction and implementing tailored interventions and support strategies. Moreover, the study’s insights contribute to the ongoing discussions surrounding the conceptualization and classification of shopping addiction, supporting its recognition as a distinct behavioral addiction deserving attention and intervention.

While this study has provided valuable contributions to the understanding of shopping addiction and the utility of the BSAS, future research should aim to replicate these findings in larger, more diverse samples and explore additional factors influencing shopping addiction risk and presentation. Longitudinal studies could also provide insights into the stability and progression of shopping addiction over time, informing the development of effective prevention and early intervention strategies.

In summary, the study’s findings enhance our understanding of shopping addiction and the BSAS’s role in its assessment, paving the way for more accurate, personalized, and effective interventions and support strategies tailored to individuals’ specific needs and experiences.