AbstractIn a randomized study with longitudinal data on a mediator and outcome, estimating the direct effect of treatment on the outcome at a particular time requires adjusting for confounding of the association between the outcome and all preceding instances of the mediator. When the confounders are themselves affected by treatment, standard regression adjustment is prone to severe bias. In contrast, G-estimation requires less stringent assumptions than path analysis using SEM to unbiasedly estimate the direct effect even in linear settings. In this article, we propose a G-estimation method to estimate the controlled direct effect of treatment on the outcome, by adapting existing G-estimation methods for time-varying treatments without mediators. The proposed method can accommodate continuous and noncontinuous mediators, and requires no models for the confounders. Unbiased estimation only requires correctly specifying a mean model for either the mediator or the outcome. The method is further extended to settings where the mediator or outcome, or both, are latent, and generalizes existing methods for single measurement occasions of the mediator and outcome to longitudinal data on the mediator and outcome. The methods are utilized to assess the effects of an intervention on physical activity that is possibly mediated by motivation to exercise in a randomized study. 相似文献
ABSTRACTThe aim of this study was to propose a new nine-item measure of mystical spirituality which would be [as easy as possible] for “ordinary” people (those with little or no theological education) to complete. The measure was developed and tested on data provided by 602 participants within an on-line survey. The Hall Index of Mystical Spirituality displayed excellent properties of internal consistency reliability (reporting an alpha coefficient of .93) and good construct validity, in terms of its location within the four components of psychological space, defined by psychological type theory (reporting a correlation of .30 within the measure of intuition). As a new measure of mystical spirituality further research is needed to test the usefulness of this short scale. 相似文献
Objective: Oesophageal cancer is an increasingly prevalent disease with a demanding post-curative treatment recovery period and sustained longer-term effects. Although post-curative treatment is a key transitionary period, the process of psychological adjustment for the individual is under-researched which limits the evidence base to inform supportive care. The aim of this study was to understand the process of adjustment for oesophageal cancer patients post-curative treatment, in particular the beliefs participants hold regarding their condition and how these are appraised against their experience.
Design: Serial interviews were undertaken with six oesophageal cancer patients who have recently completed curative treatment, at baseline and at 6-month follow-up using interpretative phenomenological analysis.
Results: The findings demonstrate an effortful process of adjustment, including recognising and accepting a changed self, fostering control beliefs over the course of the illness and physical sequelae, searching for meaning, developing illness coherence and moving away from self-blame.
Conclusions: This study is the first to utilise a longitudinal qualitative design in oesophageal cancer, and provides an understanding of post-treatment adjustment over time for this clinical population through which to inform clinical practice and service development. 相似文献
Two studies examined how adult age and time of measurement influence media preferences. Study 1 (using TV ratings data from 1970s to 1980s) found that the popularity of genres varied over time, but even after controlling for year, age groups differed in (a) genre choices (consistent with socioemotional selectivity theory) and (b) age of characters viewed (consistent with age identity theory). The average age of characters in each program partially mediated age differences in ratings of comedies and news, and suppressed a negative relationship between viewer age and ratings of violent programs. Study 2 (using 2005 survey data) found similar genre and character preferences. In addition, subjective age predicted age of favorite characters beyond the effect of chronological age.相似文献
An extensive body of literature has documented the widespread and damaging nature of sexual harassment among Anglo women, but little attention has focused on the experiences of women of color. The current paper begins to address this gap by comparing sexual harassment incidence rates and psychological and work–related outcomes of Hispanic and non–Hispanic White women across varying levels of cultural affiliation. Chi–square tests of association suggest that risk of harassment increases with affiliation to the mainstream U.S. culture, and hierarchical regression analyses suggest that cultural affiliation moderates the relation between sexual harassment and occupational functioning. These provocative findings are discussed in the context of social and economic vulnerability, socio–sexual norms, and cultural background. 相似文献
The present study extended person–organisation fit research by concentrating exclusively on one national culture dimension affecting organisational values: individualism–collectivism (I–C). Volunteers ( N =581) from two matched organisations (hospitals and management consultancies) in Australia and in South‐East Asia completed questionnaires measuring individuals' orientations on I–C and other organisational variables. Two types of fit were analysed: interactions between (1) individual I–C and national culture, and (2) individual I–C and organisational culture. These interactions were tested in relation to three outcome variables: organisational commitment, job satisfaction, and tenure. Both national and organisational differences were found with respect to I–C. Asian organisations were more collectivistic than Australian organisations, and hospitals were more collectivistic than management consultancies. In support of person–nation fit hypotheses, collectivists were more committed to their organisations and had longer tenure than individualists in Asian, as compared to Australian organisations. Interaction terms were significant even in the presence of direct effects of collectivism on organisational commitment and tenure. The same results were not found for job satisfaction. Predicted effects of person–organisation fit were not found at the organisational level within cultures. 相似文献