Browsing by Subject "Structural equation modelling"

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    Open Access
    Analysing the socioeconomic determinants of hypertension in South Africa: a structural equation modelling approach
    (BioMed Central, 2014-05-01) Cois, Annibale; Ehrlich, Rodney
    Abstract Background Epidemiological research has long observed a varying prevalence of hypertension across socioeconomic strata. However, patterns of association and underlying causal mechanisms are poorly understood in sub-Saharan Africa. Using education and income as indicators, we investigated the extent to which socioeconomic status is linked to blood pressure in the first wave of the National Income Dynamics Study — a South African longitudinal study of more than 15000 adults – and whether bio-behavioural risk factors mediate the association. Methods In a cross-sectional analysis, structural equation modelling was employed to estimate the effect of socioeconomic status on systolic and diastolic blood pressure and to assess the role of a set of bio-behavioural risk factors in explaining the observed relationships. Results After adjustment for age, race and antihypertensive treatment, higher education and income were independently associated with higher diastolic blood pressure in men. In women higher education predicted lower values of both diastolic and systolic blood pressure while higher income predicted lower systolic blood pressure. In both genders, body mass index was a strong mediator of an adverse indirect effect of socioeconomic status on blood pressure. Together with physical exercise, alcohol use, smoking and resting heart rate, body mass index therefore contributed substantially to mediation of the observed relationships in men. By contrast, in women unmeasured factors played a greater role. Conclusion In countries undergoing epidemiological transition, effects of socioeconomic status on blood pressure may vary by gender. In women, factors other than those listed above may have substantial role in mediating the association and merit investigation.
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    Open Access
    Creating inclusive financial sectors to address SDGs: factors that influence access from an African context
    (2020) Mugwabana, Tsimbe; Alhassan, Abdul Latif
    In many developing economies, access to and subsequent utilisation of mainstream financial services act as a barrier to financial inclusion. The merging of financial services and information technology, especially by means of mobile devices, result in consumers being able to make use of financial services at any time and place, thereby overcoming the distribution challenges and subsequent use (Gu, Lee, & Suh, 2009). This research examined the factors influencing the continued use of tech-based financial services post adoption by the Base of the Pyramid (BOP) in South Africa. The research uses the risk-benefit framework to understand usage behaviour focusing on cost, convenience, perceived ease of use and risk (security and operational) as predictor variables. The research makes use of analysed secondary data on 481 low-income individuals using the Structural equation modelling (SEM).The partial least squares structural modelling was utilised to test the hypotheses and relationship between the variables. The findings indicate that perceived benefit has a greater influence on usage than perceived risk. Even though consumers consider both benefit and risk in decision making, the expectation of potential benefits is a greater driver of usage. Convenience, cost and perceived ease of use were found to have significant impacts on usage, with the latter two having the greatest impacts. Perceived risk had a significant but weak impact on usage, with operating risk influencing usage more than security risk. The research recommends that when creating a value proposition for Fintech products, resources should be weighted more towards improving and highlighting those factors that drive the perception of benefit or value added to customers (cheaper, quicker etc.) vs. those that manage a potential risk. Customers are likely to respond positively and increase usage when there is an additional benefit to be derived.
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    Open Access
    Modelling perception-action coupling in the phenomenological experience of “hitting the wall” during long-distance running with exercise induced muscle damage in highly trained runners
    (Springer International Publishing, 2018-07-10) Venhorst, Andreas; Micklewright, Dominic P; Noakes, Timothy D
    Background “Hitting the wall” (HTW) can be understood as a psychophysiological stress process characterised by (A) discrete and poignant onset, (B) dynamic interplay between physiological, affective, motivational, cognitive, and behavioural systems, and (C) unintended alteration of pace and performance. A preceding companion article investigated the psychophysiological responses to 20-km self-paced treadmill time trials after producing exercise-induced muscle damage (EIMD) via a standardised muscle-lengthening contraction protocol. Methods A 5-step procedure was applied determining the extent to which the observed data fit the hypothesised cause-effect relationships. Running with EIMD negatively impacts performance fatigability via (A) amplified physiological responses and a non-adaptive distress response and (B) deterioration in perceived fatigability: increase in perceived physical strain precedes decrease in valence, which in turn precedes increase in action crisis, eventually dissolving the initially aspired performance goal. Results First, haematological indicators of EIMD predicted increased blood cortisol concentration, which in turn predicted increased performance fatigability. Second, perceived physical strain explained 44% of the relationship between haematological indicators of EIMD and valence, which in turn predicted increased action crisis, which in turn predicted increased performance fatigability. The observed data fitted the hypothesised dual-pathway model well with good model-fit indices throughout. Conclusions The hypothesised interrelationships between physiological strain, perception, and heuristic and deliberative decision-making processes in self-regulated and goal-directed exercise behaviour were applied, tested, and confirmed: amplified physiological strain and non-adaptive distress response as well as strain-perception-thinking-action coupling impact performance fatigability. The findings provide novel insights into the psychophysiological processes that underpin the phenomenological experience of HTW and alteration in pacing behaviour and performance.