Assessment and Robust Analysis of Survey Errors

Random measurement error and errors due to complex sampling designs may have deleterious effects on the quality of parameter estimates. This dissertation is comprised of three research papers that provide 1) an assessment of random measurement error through estimation of reliability using longitudinal, latent variable models, 2) an evaluation of the various probability weighting methods as corrections to unequal selection probabilities in multilevel models, and 3) an evaluation of several probability weighting and modeling approaches to unequal inclusion of observations in growth curve models. A popular structural equation model used to estimate reliability for a single measure observed over time is the quasi-simplex model. The quasi-simplex model (QSM) requires assumptions about the constancy of variance components over time, which may not be valid for a given sample and population. These assumptions are tested using models that extend the QSM by using multiple indicator factors. The extended models include item specific error variance and additional factor variance estimates. Reliability estimates and their standard errors for the models with and without the QSM assumptions are compared in light of model fit and test results for several scales using survey data. Reliability estimates for a general model without the QSM assumptions are generally similar to the models with the assumptions indicating that the particular QSM assumption may not be that critical to the reliability estimates obtained from these models. However, variance components due to additional factor and item specific error have the potential of affecting reliability estimates markedly when they are estimated by the model. Probability weights have traditionally been designed for single level analysis and not for use in multilevel models. A method for applying probability weights in multilevel models has been developed and has good performance with large sample sizes at each level of the model (Pfeffermann, Skinner, Holmes, Goldstein, and Rasbach, 1998). But, the multilevel weighting method in Pfeffermann, et al. can result in relatively poor estimation due to large amount of variation in the multilevel weights. This chapter includes a simulation analysis to evaluate several alternative methods for analyzing two-level models in the presence of unequal selection probabilities. The primary method of interest is to specify the level two part of the model such that it is robust to unequal selection bias in combination with weighting for unequal selection at level one. This "mixed" method does result in less bias, lower variance, and lower mean squared error for some models. A limitation is that the mixed method requires that the model is correctly specified at level two and the appropriate level one weight is used. This "mixed" method is a new approach in that it combines the Pfeffermann et al. (1998) weighting methodology at level one with the use of sample design variables at level two, rather than use the full Pfeffermann et al. approach of weighting at both levels. Panel studies often suffer from attrition and intermittent nonresponse. Panel data is also commonly selected using complex sampling techniques that include unequal selection of observations. Unequal inclusion of individuals and of repeated measures will result in biased estimates when the missing mechanism is nonignorable, that is, when missing values are related to outcomes. Probability weighting may be used to correct estimates for nonignorable unequal inclusion due to selection and intermittent nonresponse. However the growth curve models frequently used in analysis of change have not traditionally been estimated using sampling weights. These models are usually estimated using a mixed model where the repeated measures are modeled as a function of both fixed and random parameters. Whereas sampling or probability weights have traditionally been applied to marginal models, which do not include random effects parameters. In this chapter, several weighting approaches are applied to the mixed and marginal modeling frameworks using simulated and empirical data in linear growth models with continuos outcomes. Probability weighting performs the best in a marginal model when missing data are nonignorable. However, in most real situations including the empirical example provided in this chapter, probability weights may need to be combined with estimation that also utilizes variance weighting such as the GLS estimator with a correctly specified repeated measures correlation matrix as the variance weight matrix. This estimation methods can improve efficiency and decrease bias in estimates when data are missing at random (MAR)

Assessment of the Effect of Visual Impairment on Mortality through Multiple Health Pathways: Structural Equation Modeling

PURPOSE. To estimate the direct effects of self-reported visual impairment (VI) on health, disability, and mortality and to estimate the indirect effects of VI on mortality through health and disability mediators. METHODS. The National Health Interview Survey (NHIS) is a population-based annual survey designed to be representative of the U.S. civilian noninstitutionalized population. The National Death Index of 135,581 NHIS adult participants, 18 years of age and older, from 1986 to 1996 provided the mortality linkage through 2002. A generalized linear structural equation model (GSEM) with latent variable was used to estimate the results of a system of equations with various outcomes. Standard errors and test statistics were corrected for weighting, clustering, and stratification. RESULTS. VI affects mortality, when direct adjustment was made for the covariates. Severe VI increases the hazard rate by a factor of 1.28 (95% CI: 1.07-1.53) compared with no VI, and some VI increases the hazard by a factor of 1.13 (95% CI: 1.07-1.20). VI also affects mortality indirectly through self-rated health and disability. The total effects (direct effects plus mediated effects) on the hazard of mortality of severe VI and some VI relative to no VI are hazard ratio (HR) 1.54 (95% CI: 1.28-1.86) and HR 1.23 (95% CI: 1.16-1.31), respectively. CONCLUSIONS. In addition to the direct link between VI and mortality, the effects of VI on general health and disability contribute to an increased risk of death. Ignoring the latter may lead to an underestimation of the substantive impact of VI on mortality

Final Report: Paths to QUALITY Evaluation

Paths to QUALITY Evaluation—Phase 2 Final Report to the Indiana Office of Early Childhood and Out of School Learning Family and Social Services Administration March, 201

Patient and provider characteristics associated with communication about opioids: An observational study

Objective Our objective is to examine the relationship of patient and provider characteristics and communication with chronic non-cancer pain and opioid management in primary care. Method We conducted an observational study using audio-recorded primary care appointments (up to 3/patient) and self-reported assessments of primary care providers (PCPs) and patients. We coded visit transcripts for 1) opioid and pain management talk and 2) mental health and opioid safety talk. Results Eight PCPs and 30 patients had complete data for 78 clinic visits. PCPs and patients engaged in more opioid and pain management talk when patients reported greater pain catastrophizing and PCPs reported higher psychosocial orientation. PCPs and patients engaged in talk about mental health and opioid safety when patients reported greater anxiety, higher working alliance with their PCP, and when PCPs reported higher burnout. PCPs’ negative attitudes about opioids were associated with fewer discussions about mental health and opioid safety. Conclusions Our results should facilitate design of interventions that improve communication and, ultimately, pain outcomes for patients. Practice Implications Clinicians can use our results to increase patient engagement in discussions about opioid use and pain management or mental health and safety discussions

Walking for our health: couple-focused interventions to promote physical activity in older adults

More than 50% of U.S. adults do not engage in sufficient physical activity to meet current recommendations, making physical activity change and maintenance a priority for health promotion throughout adulthood. Among married partners, change in physical activity of one partner often is concordant with change of activity of the other. The primary purpose of this study was to examine two couple-focused interventions that capitalize on the co-occurrence of health behavior change within couples to promote physical activity in older adults. In this study, partners (N = 31 couples) participated together in assessment and intervention activities, and were randomized together into one of two couple-focused conditions. In one condition (concurrent), standard goal-setting techniques were extended to a couple-focused design with each partner setting daily step goals and monitoring her or his own progress. In the other condition (combined), partners collaborated to set and monitor shared daily step goals. Physical activity was assessed with accelerometers pre- and post-intervention. Post-intervention, average weekly physical activity increased by 58 min (p \u3c 0.001), and average body mass index (BMI) decreased by 0.50 kg/m2 (p = 0.001), from pre-intervention measures. Similar levels of change in weekly physical activity and in BMI were detected in both intervention groups. Furthermore, participants demonstrated high adherence to the intervention protocol. Results suggest that couple-focused physical activity interventions can be effective in eliciting increases in physical activity among older adults. Further research is needed to uncover interpersonal mechanisms that maximize physical activity promotion and maintenance within couples over time

Feeding-induced changes in allatostatin-A and short neuropeptide F in the antennal lobes affect odor-mediated host seeking in the yellow fever mosquito, <i>Aedes aegypti</i>

Aedes aegypti is a model species in which the endogenous regulation of odor-mediated host seeking behavior has received some attention. Sugar feeding and host seeking in female A. aegypti are transiently inhibited following a blood meal. This inhibition is partially mediated by short neuropeptide F (sNPF). The paired antennal lobes (ALs), as the first processing centers for olfactory information, has been shown to play a significant role in the neuropeptidergic regulation of odor-mediated behaviors in insects. The expression of sNPF, along with other peptides in the ALs of A. aegypti, indicate parallel neuromodulatory systems that may affect olfactory processing. To identify neuropeptides involved in regulating the odor-mediated host seeking behavior in A. aegypti, we use a semi-quantitative neuropeptidomic analysis of single ALs to analyze changes in the levels of five individual neuropeptides in response to different feeding regimes. Our results show that the level of sNPF-2, allatostatin-A-5 (AstA-5) and neuropeptide-like precursor-1-5 (NPLP-1-5), but not of tachykinin-related-peptides and SIFamide (SIFa), in the AL of female mosquitoes, changes 24 h and 48 h post-blood meal, and are dependent on prior access to sugar. To assess the role of these neuropeptides in modulating host seeking behavior, when systemically injected individually, sNPF-2 and AstA-5 significantly reduced host seeking behavior. However, only the injection of the binary mixture of the two neuropeptides lead to a host seeking inhibition similar to that observed in blood fed females. We conclude that modulation of the odor mediated host seeking behavior of A. aegypti is likely regulated by a dual neuropeptidergic pathway acting in concert in the ALs

A general approach for estimating scale score reliability for panel survey data.

Scale score measures are ubiquitous in the psychological literature and can be used as both dependent and independent variables in data analysis. Poor reliability of scale score measures leads to inflated standard errors and/or biased estimates, particularly in multivariate analysis. To assess data quality, reliability estimation is usually an integral step in the analysis of scale score data. Cronbach’s α is a widely used indicator of reliability but, due to its rather strong assumptions, can be a poor estimator (Cronbach, 1951). For longitudinal data, an alternative approach is the simplex method; however, it too requires assumptions that may not hold in practice. One effective approach is an alternative estimator of reliability that relaxes the assumptions of both Cronbach’s α and the simplex estimator and, thus, generalizes both estimators. Using data from a large-scale panel survey, the benefits of the statistical properties of this estimator are investigated and its use is illustrated and compared with the more traditional estimators of reliability

The effects of a psychosocial dimension of socioeconomic position on survival: occupational prestige and mortality among US working adults

The association between education or income and mortality has been explored in great detail. These measures capture both the effects of material disadvantage on health and the psychosocial impacts of a low socioeconomic position on health. When explored independently of educational attainment and income, occupational prestige – a purely perceptual measure – serves as a measure of the impact of a psychosocial phenomenon on health. For instance, a fire-fighter, academician or schoolteacher may carry the social benefits of a higher social status without actually having the income (in all cases) or the educational credentials (in the case of the fire-fighter) to match. We explored the independent influence of occupational prestige on mortality. We applied Cox proportional hazards models to a nationally representative sample of over 380,000 US workers who had worked at any time between 1986 and 1994 with mortality follow up through 2002. We found that occupational prestige is associated with a decrease in the risk of all-cause, cancer, cardiovascular and respiratory-related mortality after controlling for household income and educational attainment. We further investigated the question of whether the effects of prestige are moderated by sex and broader occupational groupings. Prestige effects operate in white-collar occupations for men only and within service occupations for all workers

A multi-study examination of the role of repeated spaced retrieval in the word learning of children with developmental language disorder

Background Many children with developmental language disorders (DLD) have well-documented weaknesses in vocabulary. In recent years, investigators have explored the nature of these weaknesses through the use of novel word learning paradigms. These studies have begun to uncover specific areas of difficulty and have provided hints about possible intervention strategies that might help these children learn words more accurately and efficiently. Among the studies of this type are those that incorporate repeated spaced retrieval activities in the learning procedures. Methods In this study, we examined the data from four of these studies that employed the same types of participants (4- and 5-year-old children with DLD and same-age children with typical language development), research design, and outcome measures. The studies differed primarily in the type of learning condition that was being compared to a spaced retrieval condition. A mixed-effects modeling framework was used, enabling the data from the four studies and different outcome measures to be aggregated. Results Across the studies, more words in the repeated spaced retrieval condition were recalled than those in the comparison conditions. This was true regardless of outcome measure. Children with typical language development recalled more words than the children with DLD. Both groups benefited from spaced retrieval, though effects were larger for the group with DLD. Children recalled words as accurately 1 week after learning as they did at the 5-min mark; the two groups were essentially identical in this respect. Conclusions Overall, the findings support the continued refinement of these types of repeated spaced retrieval procedures, as they may have potential to serve as effective approaches to intervention