Measurement of Perceived Stress in Age-Related Macular Degeneration

The Perceived Stress Scale is essentially unidimensional: Complementary evidence from ancillary bifactor indices and Mokken analysis

Stress is a significant contributor to physical and mental health. However, there is considerable variability in response to stress, underscoring the role of stress perception in health outcomes. Perceptions of stress are influenced by socio-demographic and cultural factors. The Perceived Stress Scale (PSS) has been used extensively to assess stress among different populations and for cross-cultural comparisons. Given its wide-ranging application, the rigorous assessment of its psychometric properties is necessary to solidify its standing as a dependable measure. The scale was originally conceptualized as unidimensional but there has been controversy regarding its factor structure, leading to various factor models. Conclusions about the structure of the PSS were largely based on fit indices in confirmatory factor analysis and often did not go beyond fit indices. In addition, classical test theory indices are sample dependent and it is not surprising that instruments can exhibit different properties in different samples. Over reliance on fit indices can lead to overly simplistic interpretations of underlying dimensionality. Hence, the current study extends this research by using item response theory and examining ancillary bifactor indices to determine the amount of variance explained by the total scale and subscales. Participants were students (n = 322) at a South African institution who completed the PSS and a demographic questionnaire. Fit indices in confirmatory factor analysis indicated that a one-factor model, a bifactor model and a correlated-two factor model fit the data to an acceptable degree (GFI > 0.95, CFI > 0.90, RMSEA <0.08). Ancillary bifactor indices supported the essential unidimensionality of the scale as the two subscales accounted for 18.9 % and 17.2 %, of the variance, respectively, while the total scale accounted for 63.9 % of the variance. This was confirmed by Mokken analysis, which indicated that all the items loaded on one scale. The unidimensionality of the PSS suggests that it can be an effective clinical screening tool and that it is easily adaptable across different populations and contexts, enabling standardized comparisons. However, it may lose sensitivity to cultural differences in how stress is perceived and experienced. Hence, integrating the PSS with tailored assessments would facilitate a more robust and inclusive approach to stress assessment in various settings and populations. The study did not take specific sources of stress into account and was conducted among a distinct population group. Future studies undertaken among diverse populations and linking global stress with the impact of stressful life events are needed to further confirm our results and understand the interconnection between these factors.

The management of neovascular age-related macular degeneration: A systematic literature review of patient-reported outcomes, patient mental health and caregiver burden

PURPOSE

The aim of this systematic literature review was to describe patient-reported outcomes, mental health and caregiver burden in patients with neovascular age-related macular degeneration (nAMD) treated with anti-vascular endothelial growth factor (VEGF) agents in routine clinical practice.

METHODS

Electronic searches were conducted in Embase and MEDLINE according to pre-defined criteria.

RESULTS

Of 856 records identified, 63 met inclusion criteria. Depression or depressive symptoms were reported in up to 42% of patients with nAMD. Of 25/63 (40%) studies evaluating quality of life (QoL) and using various tools, eight studies reported composite National Eye Institute Visual Functioning Questionnaire scores following anti-VEGF treatment. Of these, seven reported a statistically significant improvement at the earliest time point measured (Month 3-12) and approximately 50% reported sustained QoL benefits at 12 months. In studies comparing the attributed or different regimens, the most important factor from the patient's perspective was the likelihood that a particular regimen would maintain vision. There was a preference towards treat and extend, which was associated with a perceived reduction in patient and caregiver burden, compared to fixed dosing.

CONCLUSIONS

A coordinated holistic approach to patient care is key to optimizing patient well-being as well as visual outcomes. Further research regarding the patient-reported impact of nAMD management outside the trial setting (particularly international longitudinal studies) is warranted. Standardization of QoL studies would assist in establishing whether sustained QoL improvement, rather than prevention of QoL decline, should be a realistic expectation of treatment of nAMD in the longer term.

Perceived Stress and Perceived Lack of Control of Spanish Education-Degree University Students: Differences Dependent on Degree Year, Basis for Admission and Gender

Stress in higher education students is an issue of growing concern, as stress impacts quality of life and has been linked to drop-out from higher education. The aim was to investigate how stress was related to how far along students were in their degree program, using the Spanish Perceived Stress Scale (PSS10). We expected 1) first-year education students to experience more perceived lack of control than second-year students, 2) second-year students to experience more perceived stress than first-year students. Participants were students in three university education-degree programs (N = 399). The psychometric properties of the Perceived Stress (PS) and Perceived Lack of Control (PLC) subscales were investigated using Rasch models. One item was eliminated from each subscale. The estimated interval-level Rasch scores were utilized for testing hypotheses with general linear models. Results showed a somewhat more complex pattern than predicted as interaction effects between degree year and gender and between degree year and basis for admission were found.

An Exploration of Stress: Leveraging Online Data from Crowdsourcing Platforms

Background: Early detection of community health risk factors such as stress is of great interest to health policymakers, but representative data collection is often expensive and time-consuming. It is important to investigate the use of alternative means of data collection such as crowdsourcing platforms.

Methods: An online sample of Amazon Mechanical Turk (MTurk) workers (N = 500) filled out, for themselves and their child, demographic information and the 10-item Perceived Stress Scale (PSS-10), designed to measure the degree to which situations in one’s life are appraised as stressful. Internal consistency reliability of the PSS-10 was examined via Cronbach’s alpha. Analysis of variance (ANOVA) was utilized to explore trends in the average perceived stress of both adults and their children. Last, Rasch trees were utilized to detect differential item functioning (DIF) in the set of PSS-10 items.

Results: The PSS-10 showed adequate internal consistency reliability (Cronbach’s alpha = 0.73). ANOVA results suggested that stress scores significantly differed by education (p = 0.024), employment status (p = 0.0004), and social media usage (p = 0.015). Rasch trees, a recursive partitioning technique based on the Rasch model, indicated that items on the PSS-10 displayed DIF attributable to physical health for adults and social media usage for children.

Conclusion: The key conclusion is that this data collection scheme shows promise, allowing public health officials to examine health risk factors such as perceived stress quickly and cost effectively.

Age-Related Macular Degeneration: What Do We Know So Far?

Ageing is a natural process that everyone experiences and nobody is an exception. With ageing, our body experiences physiological changes. In this article, the focus is made on the physiological changes of our eyes related to ageing and age-related macular degeneration (AMD), which is the most common cause of incurable visual impairment in developed countries. With ageing populations increasing in many countries, more and more patients will have AMD in a foreseeable future. In Eastern Europe, blindness due to AMD, currently, is approximately 20% and there has been an increasing trend depicted in the future. Generally, AMD can be divided into early stages and two forms in an advanced (late) stage. Advanced AMD form includes neovascular AMD (wet) and geographic atrophy (late dry), both of these are associated with substantial, progressive visual impairment. The pathogenesis of AMD is complex and, by far, not completely understood. Multiple factors have been studied, for example: environmental factor, genetic factor (complement factor H), lifestyle. It has been proved that they are linked to higher the risk of developing of AMD, however, the actual pathogenesis is not yet formulated. AMD progression can also be a culprit to certain biochemical events and molecular changes linked to inflammation and pathological angiogenesis. In nowadays, we do have diagnostic methods for both early and late forms of AMD as well as ways to prevent progression of early AMD and wet AMD. However, until now, there is still no treatment for dry AMD. This article is a brief review of AMD and may hopefully lead to some future directions in early diagnostic methods and treating dry AMD.

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

Background

In Australia, the stress levels have increased over the years, impacting on the physical and mental health of the general population. The aim of the present study was to evaluate the validity and reliability of the PSS-14 in an Australian population.

Methods

The PSS-14 was applied to a large national sample comprising 3857 Australians in the population-based cross-sectional study Australia’s National Survey of Adult Oral Health 2004–2006. The psychometric properties analyzed with the Rasch model and Graphical Log-linear Rasch models were: model fit, item fit, local dependence, differential item functioning, unidimensionality, reliability, targeting and criterion validity.

Results

The PSS-14 did not fit the pure RM (χ2 (55) = 3828.3, p = < 0.001) and the unidimensionality of the whole scale was rejected (p = < 0.001). The Perceived Stress (χ2 (27) = 1409.7, p = < 0.001) and Perceived Control (χ2 (27) = 713.4, p = < 0.001) subscales did not fit the pure RM. After the deletion of two items, the Perceived Stress subscale (χ2 (96) = 94.4, p = 0.440) fitted a GLLRM, while the Perceived Control scale (χ2 (55) = 62.50, p = 0.224) fitted a GLLRM after the exclusion of four misfitting items.

Conclusions

The Perceived Stress subscale displayed adequate psychometric properties after the deletion of two items; however, the majority of problems centered around the Perceived Control subscale. The presence of differential item functioning among four items indicates that adjustment of total scores is required to avoid measurement bias. Recommendations for future applications in Australia are provided.

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

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 (χ2 (21) = 11.74, p = 0.946) and Perceived Coping (χ2 (28) = 17.63, p = 0.935) subscales fitted the Rasch model. Reliability was modest (PersonSeparationIndexdistress = 0.72; PersonSeparationIndexcoping = 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.