Investigating method effects associated with the wording direction of items of the Social Physique Anxiety Scale

The dimensionality of the Perceived Stress Scale: The presence of opposing items is a source of measurement error

INTRODUCTION

The Perceived Stress Scale (PSS) is a widely recognized patient-reported outcome measure designed to assess an individual's level of perceived stress. The PSS consists of ten items, with six items phrased negatively and four phrased positively. Most studies have found that the PSS consists of two dimensions, with negative and positive items forming separate dimensions. However, some studies suggest a one-dimensional construct.

OBJECTIVE

We aimed to investigate the dimensionality of the PSS and the impact of wording effects on the measurement properties of the scale.

METHODS

We tested a modified version of the PSS (mPSS), with negative wording of all items. In a Danish sample, respondents were randomized to answer the PSS or the mPSS. We used confirmative factor analysis and Rasch analysis to assess the validity and reliability of the two versions. The proportion of person misfit was also evaluated.

RESULTS

A total of 326 respondents completed the PSS, whereas 306 completed the mPSS. For the PSS, a two-factor model fitted the data best, and the first positively formulated item showed under-discrimination (Rasch model item fit rejected). The mPSS had higher measurement precision than the PSS, but evidence of local dependence was seen for both versions. Fewer respondents gave improbable responses to the mPSS compared to the PSS.

LIMITATIONS

Data comes from three different respondent samples.

CONCLUSION

The PSS was deemed essentially unidimensional, with the extra variance being attributed to the reversed items. To reduce response bias, clinicians and researchers may apply the mPSS.

Social Appearance Anxiety Scale: a psychometric investigation and evaluation of the influence of individual characteristics on social appearance anxiety in Brazilian adults who practice physical exercise

Introduction

Evaluating signs of anxiety related to body appearance is becoming increasingly important in contemporary society and, in this sense, the Social Appearance Anxiety Scale (SAAS) seems an interesting alternative of measurement.

Objectives

To evaluate the psychometric properties of the Portuguese version of the SAAS when applied to Brazilian adults who practice physical exercise and verify the influence of individual characteristics on participants' social appearance anxiety.

Methods

This was a cross-sectional study conducted online. The participants completed the SAAS and a demographic questionnaire. The psychometric properties of the SAAS one-factor model were evaluated using confirmatory factor analysis. A structural model was built for men and women to verify the influence of individual characteristics of the participants on social appearance anxiety.

Results

1,495 individuals participated in the study (70.8% women; mean age = 29.5, SD = 8.9 years). The data obtained with the SAAS presented good indicators of validity and reliability for both genders (CFI > 0.97, TLI > 0.97, SRMR = 0.04, α > 0.97, ω > 0.85). For both men and women, greater levels of social appearance anxiety were observed among younger participants, who had a higher body mass index, self-reported an eating disorder, and perceived a change in their body after the onset of the COVID-19 pandemic. For women specifically, higher income and having started physical exercise more recently were associated with greater levels of social appearance anxiety.

Conclusion

The findings supported the validity and reliability of the data obtained with the SAAS and revealed that when investigating social appearance anxiety in future research and clinical protocols, specific individual characteristics should be considered.

Environmental health knowledge of healthcare professionals: Instrument development and validation using the Rasch model

INTRODUCTION

environmental risk factors constitute a major public health issue, calling for preventive actions and interventions at multiple levels. An important step in this direction is increasing the environmental health (EH) knowledge of the healthcare professionals. In this context, tools designed to measure such knowledge are of imperative importance. The aim of the present study was to develop an EH knowledge tool for healthcare professionals.

METHODS

a group of experts defined the knowledge areas of the EH tool and their corresponding items. An online pilot and a validation study were performed. Internal consistency reliability was measured with the Kuder-Richardson 20 (KR-20) estimate, the construct validity and uni-dimensionality of the tool were assessed with the Rasch model. Known-groups validity was analysed with the two-sample t-test.

RESULTS

a total of n = 151 and n = 444 healthcare professionals and end-year medical and nursing students, participated in the pilot and the validation study, respectively. The resulting 33-item EH knowledge questionnaire for healthcare professionals (EHKQ-HP) obtained a KR-20 = 0.82. The scale is uni-dimensional. Its construct validity was verified, and its items cover a wide range of difficulties. Separation statistics were adequate and known-groups behaved as hypothesized.

CONCLUSIONS

the EHKQ-HP is a valuable resource for measuring the EH knowledge of the healthcare professionals. As such it will be useful in detecting EH knowledge gaps, and helping public health agents in making informed decisions when developing interventions for increasing this very knowledge. This would consequently help in improving the health of the general population.