Stress beyond coping? A Rasch analysis of the Perceived Stress Scale (PSS-14) in an Aboriginal population

Abstract

The history of colonization contributed to Aboriginal and Torres Strait Islanders becoming one of the most disadvantaged groups in Australia. The multiple social inequalities, and therefore the constant insecurities for many about low income, poor living conditions, unemployment, and discrimination, generate chronic stress in this population. In the Baby Teeth Talk Study, an oral-health randomized controlled trial, the Perceived Stress Scale (PSS-14) was administered to 367 pregnant Aboriginal women at baseline. The aim of the present study was to evaluate the validity and reliability of the PSS-14 in an Aboriginal population. The study analysed: (a) model fit; (b) dimensionality; (c) local dependence; (d) differential item functioning; (e) threshold ordering and item fit; (f) targeting; (g) reliability; and (h) criterion validity. The dimensionality analysis indicated a two-factor structure, with negatively and positively worded items clustering together and 21.7% (95% Agresti-Coull C.I. [17.8%, 26.2%]) statistically significant t-tests between the persons’ estimates. After the creation of composite items, the revised Perceived Distress (χ 2 (21) = 11.74, p = 0.946) and Perceived Coping (χ 2 (28) = 17.63, p = 0.935) subscales fitted the Rasch model. Reliability was modest (PersonSeparationIndex distress = 0.72; PersonSeparationIndex coping = 0.76). The latent correlation between the Perceived Distress and Perceived Coping subscales was r = 0.14. It is hypothesized that the social inequalities experienced by the Aboriginal population are so pronounced that even Aboriginal pregnant women that perceived themselves as coping well with life challenges ended up endorsing items regarding high levels of stress. The present research showed that a revised PSS-14 is a culturally valid and modestly reliable psychological instrument to measure stress in a population of pregnant Aboriginal women in Australia.

Measuring stress in Australia: validation of the perceived stress scale (PSS-14) in a national sample

“…The Aboriginal Australians experiences of well-being are rather distinct from western individuals [30] and "Western psychological concepts are inappropriate and potentially damaging to Indigenous people" [31]. One example is the PSS-14, which was recently validated for an Aboriginal population and the findings showed a weak latent correlation between the "Perceived Stress" and "Perceived Coping" subscales (r = 0.14), a result distinct from the moderate (r = 0.50) to strong (0.70) correlations found in western societies [32]. For these reasons, we followed the recent recommendations by Kowal, Gunthorpe [31] and Santiago, Roberts [32] that ABTSI are a culturally distinct group in which psychological instruments should be evaluated separately from the general Australian population.…”

“…All participants provided signed informed consent [44]. A sample of 42 Aboriginal Australians was removed from the analysis since the PSS-14 has been previously validated for this group [32] and it is recommended that psychometric research with Indigenous groups should be conducted separately due to cultural differences [31].…”

Sense of personal control: Can it be assessed culturally unbiased across Aboriginal and non-Aboriginal Australians?

“…Secondly, recent recommendations by Santiago and colleagues [20] emphasized the importance of validating psychological instruments specifically for Aboriginal Australians and it seems particularly important to validate measures of personal control for culturally defined subpopulations since personal control is influenced by culture [21]. For example, the association of personal control with anxiety symptoms is weaker in collectivist societies compared to individualistic (western) societies [21]; moreover, individuals from collectivist cultures (e.g.…”

“…This result is worrisome since, although Aboriginal Australians comprise several culturally distinct groups, this population is notably homogeneous due to their experience of social inequalities as a whole [1]. Hence, when psychological assessment is performed with Aboriginal Australians, the low trait variance (respondents are similar) needs to be compensated with higher measurement precision [20]. These findings imply that future studies need to develop culturally sensitive items to improve the PC subscale.…”

Drop-the-p: Bayesian CFA of the Multidimensional Scale of Perceived Social Support in Australia

“…For instance, validation studies of other instruments showed "slight differences in the strength of associations with other constructs in convenience and representative samples, " warranting further investigation (Leckelt et al, 2018). In Australia, one study validated an instrument (to measure perceived stress) in a restricted Indigenous subpopulation reporting good psychometric properties (Santiago et al, 2019) that have not been replicated at a national level (Santiago et al, 2020). In conclusion, while it is possible that psychometric properties of an instrument generalize from restricted subgroups to the national population, independent validation in national samples still seems to be required.…”