31 research outputs found
Multilevel models for the experimental psychologist: Foundations and illustrative examples
Multilevel Models for the Experimental Psychologist: Foundations and Illustrative Examples
Although common in the educational and developmental areas, multilevel models are not often utilized in the analysis of data from experimental designs. This article illustrates how multilevel models can be useful with two examples from experimental designs with repeated measurements not involving time. One example demonstrates how to properly examine independent variables for experimental stimuli or individuals that are categorical, continuous, or semicontinuous in the presence of missing data. The second example demonstrates how response times and error rates can be modeled simultaneously within a multivariate model in order to examine speed–accuracy trade-offs at the experimental-condition and individual levels, as well as to examine differences in the magnitude of effects across outcomes. SPSS and SAS syntax for the examples are available electronically
Exploring the benefits of Respite Services to Family Caregivers: Methodological issues and current Findings
Objectives: There is growing emphasis on empirical validation of the efficacy of community-based services for older people and their families, but research on services such as respite care faces methodological challenges that have limited the growth of outcome studies. We identify problems associated with the usual research approaches for studying respite care, with the goal of stimulating use of novel and more appropriate research designs that can lead to improved studies of community-based services. Method: Using the concept of research validity, we evaluate the methodological approaches in the current literature on respite services, including adult day services, in-home respite and overnight respite. Results: Although randomized control trials (RCTs) are possible in community settings, validity is compromised by practical limitations of randomization and other problems. Quasi-experimental and interrupted time series designs offer comparable validity to RCTs and can be implemented effectively in community settings. Conclusion: An emphasis on RCTs by funders and researchers is not supported by scientific evidence. Alternative designs can lead to development of a valid body of research on community services such as respite
Modeling cortisol daily rhythms of family caregivers of individuals with dementia: Daily stressors and adult day services use
Objectives: The study examined the typical diurnal cortisol trajectory and its differential associations with an intervention, the adult day services (ADS) use, among a sample of family caregivers who experienced high levels of daily stress. Method: On hundred and sixty-five caregivers of individuals with dementia completed an 8-day diary on daily stressors, positive events, sleep quality, and ADS use. The caregivers also provided five saliva samples on each diary day. Daily cortisol trajectories were modeled as a function of time elapsed since awakening, and three spline growth curve models were fit to the cortisol data. Based on the best-fitting linear spline model, the effect of daily ADS use was examined at both daily and person levels. Covariates included daily experiences and other caregiving characteristics. Results: On ADS days, caregivers had a steeper cortisol awakening response (CAR) slope and a steeper morning decline. ADS use remained significant after controlling for covariates at both daily and person levels. Discussion: The findings suggested potential biophysiological benefits of daily ADS use for a sample that was under chronic stress and high levels of daily stress
Care Transitions and Adult Day Services Moderate the Longitudinal Links between Stress Biomarkers and Family Caregivers' Functional Health
Intrinsic emotional fluctuation in daily negative affect across adulthood
Objectives: The study explored daily negative affect (NA) fluctuation, its associations with age, and its developmental characteristics. Method: The sample (n = 790) was drawn from the Midlife Development in the United States; participants completed two 8-day daily diaries 10 years apart. Multilevel models were estimated within each diary component, where two single daily NA (depression and nervousness) and daily NA diversity were predicted separately by daily stressor exposures, physical health symptoms, age, gender, education, and neuroticism. The variances of within-person residual were output for single NA and NA diversity as intrinsic emotion fluctuation (IEF) within each diary component (i.e., controlled for within- and between-person contextual factors). Then multilevel growth models were fit to explore the developmental characteristics of day-to-day IEF across 10 years. Results: At the daily level, older age was associated with less IEF in depression and nervousness. Over time, IEF in depression decreased. Additionally, IEF in NA diversity increased for older participants longitudinally. Discussion: IEF represents a new conceptualization of midlife individuals’ daily emotional ups and downs, specifically, the intrinsic within-person volatility of emotions. The magnitude of IEF and its longitudinal dynamics may have implications for health and well-being of middle-aged adults