89 research outputs found
Patterns of Dental Service Utilization Following Nontraumatic Dental Condition Visits to the Emergency Department in Wisconsin Medicaid
Objectives: To examine patterns of dental service utilization for adult Medicaid enrollees in Wisconsin following nontraumatic dental condition (NTDC) visits to the emergency department (ED).
Methods: This is a retrospective, observational study of claims for NTDC visits to the ED and dental service encounters from the Wisconsin Medicaid Evaluation and Decision Support database (2001-2009). We used competing risk models to predict probabilities of returning to the ED versus obtaining follow-up care from a dentist.
Results: We observed a 43 percent increase in the rate of NTDC visits to the ED, with most of this increase occurring from 2001 to 2005. Within 30 days of an NTDC visit to the ED, ∼29.6 percent of enrollees will first visit a dentist office, while ∼9.9 percent will return to the ED. Young to middle-aged adults (18 toyears) and enrollees living in counties with a lower supply of dental providers were more likely to return to the ED following a NTDC visit. Among the enrollees that first visited a dental office following an ED visit, 37.6 percent had an extraction performed at this visit.
Conclusions: Almost one in five adult Medicaid enrollees will subsequently return to the ED following a previous NTDC visit. The provision of definitive care for these individuals appears to primarily consist of extractions
Six Degrees of Epistasis: Statistical Network Models for GWAS
There is growing evidence that much more of the genome than previously thought is required to explain the heritability of complex phenotypes. Recent studies have demonstrated that numerous common variants from across the genome explain portions of genetic variability, spawning various avenues of research directed at explaining the remaining heritability. This polygenic structure is also the motivation for the growing application of pathway and gene set enrichment techniques, which have yielded promising results. These findings suggest that the coordination of genes in pathways that are known to occur at the gene regulatory level also can be detected at the population level. Although genes in these networks interact in complex ways, most population studies have focused on the additive contribution of common variants and the potential of rare variants to explain additional variation. In this brief review, we discuss the potential to explain additional genetic variation through the agglomeration of multiple gene–gene interactions as well as main effects of common variants in terms of a network paradigm. Just as is the case for single-locus contributions, we expect each gene–gene interaction edge in the network to have a small effect, but these effects may be reinforced through hubs and other connectivity structures in the network. We discuss some of the opportunities and challenges of network methods for analyzing genome-wide association studies (GWAS) such as the study of hubs and motifs, and integrating other types of variation and environmental interactions. Such network approaches may unveil hidden variation in GWAS, improve understanding of mechanisms of disease, and possibly fit into a network paradigm of evolutionary genetics
Provision of Fluoride Varnish Treatment by Medical and Dental Care Providers: Variation by Race/Ethnicity and Levels of Urban Influence
Objective: In 2004, Wisconsin Medicaid policy changed to allow medical care providers to be reimbursed for fluoride varnish treatment (FVT) to children\u27s teeth to improve access and utilization. To date, no study has been published on whether geographic and racial/ethnic variation in the provision of FVT in response to this policy change exists. This study\u27s objective is to examine the association of rates of FVT for children enrolled in Wisconsin Medicaid with race/ethnicity, urban influence codes (UIC), and dental health professional shortage area (DHPSA) designation based on county of residence.
Methods: A retrospective, pre–post design was used based on FVT claims for children in the Wisconsin Medicaid program from 2002 to 2006. Poisson regression models were used to evaluate the association of rates of FVT claims with race/ethnicity, UIC, and DHPSA designation.
Results: The rate of FVT claims varied by resident county-type according to UIC and DHPSA designation, age, and race/ethnicity. Post-policy, the largest increases were observed for Native Americans residing in non-DHPSA counties, enrollees living in rural counties, and for Hispanics living in partial and entire DHPSA counties. African-Americans residing in partial DHPSA and metropolitan counties displayed the lowest rates of FVT claims.
Conclusions: Overall access and utilization of FVT increased, but substantial racial/ethnic and geographic variation in the provision of FVT for children enrolled in Wisconsin Medicaid was observed. Future policies should incorporate measures that will specifically address the racial and geographic variations identified in this study
Role of a plausible nuisance contributor in the declining obesity-mortality risks over time.
CONTEXT: Recent analyses of epidemiological data including the National Health and Nutrition Examination Survey (NHANES) have suggested that the harmful effects of obesity may have decreased over calendar time. The shifting BMI distribution over time coupled with the application of fixed broad BMI categories in these analyses could be a plausible nuisance contributor to this observed change in the obesity-associated mortality over calendar time.
OBJECTIVE: To evaluate the extent to which observed temporal changes in the obesity-mortality association may be due to a shifting population distribution for body mass index (BMI), coupled with analyses based on static, broad BMI categories.
DESIGN, SETTING, AND PARTICIPANTS: Simulations were conducted using data from NHANES I and III linked with mortality data. Data from NHANES I were used to fit a true model treating BMI as a continuous variable. Coefficients estimated from this model were used to simulate mortality for participants in NHANES III. Hence, the population-level association between BMI and mortality in NHANES III was fixed to be identical to the association estimated in NHANES I. Hazard ratios (HRs) for obesity categories based on BMI for NHANES III with simulated mortality data were compared to the corresponding estimated HRs from NHANES I.
MAIN OUTCOME MEASURES: Change in hazard ratios for simulated data in NHANES III compared to observed estimates from NHANES I.
RESULTS: On average, hazard ratios for NHANES III based on simulated mortality data were 29.3% lower than the estimates from NHANES I using observed mortality follow-up. This reduction accounted for roughly three-fourths of the apparent decrease in the obesity-mortality association observed in a previous analysis of these data.
CONCLUSIONS: Some of the apparent diminution of the association between obesity and mortality may be an artifact of treating BMI as a categorical variable
A Method to Assess Linkage Disequilibrium between CNVs and SNPs Inside Copy Number Variable Regions
Since the discovery of the ubiquitous contribution of copy number variation to genetic variability, researchers have commonly used metrics such as r2 to quantify linkage disequilibrium (LD) between copy number variants (CNVs) and single nucleotide polymorphisms (SNPs). However, these reports have been restricted to SNPs outside copy number variable regions (CNVR) as current methods have not been adapted to account for SNPs displaying variable copy number. We show that traditional LD metrics inappropriately quantify SNP/CNV covariance when SNPs lie within CNVR. We derive a new method for measuring LD that solves this issue, and defaults to traditional metrics otherwise. Finally, we present a procedure to estimate CNV–SNP allele frequencies from unphased CNV–SNP genotypes. Our method allows researchers to include all SNPs in SNP/CNV LD measurements, regardless of copy number
A psychometric evaluation of the PedsQL™ Family Impact Module in parents of children with sickle cell disease
<p>Abstract</p> <p>Background</p> <p>Caring for a child with a chronic condition, such as sickle cell disease, can have a significant impact on parents and families. In order to provide comprehensive care and support to these families, psychometrically sound instruments are needed as an initial step in measuring the impact of chronic diseases on parents and families. We sought to evaluate the psychometric properties of the PedsQL™ Family Impact Module in populations of children with and without sickle cell disease. In addition, we sought to determine the correlation between parent's well being and their proxy report of their child's health-related quality of life (HRQL).</p> <p>Methods</p> <p>We conducted a cross-sectional study of parents of children with and without sickle cell disease who presented to an urban hospital-based sickle cell disease clinic and an urban primary care clinic. We assessed the HRQL and family functioning of both groups of parents utilizing the PedsQL™ Family Impact Module. The reliability, validity and factor structure of the instrument were determined and scores from the instrument were correlated with scores from parent-proxy report of their child's HRQL using the PedsQL™ 4.0 Generic Core Scales.</p> <p>Results</p> <p>Parents of 170 children completed the module (97 parents of children with sickle cell disease and 73 parents of children without sickle cell disease). The Family Impact Module had high ceiling effects but was reliable (Cronbach's alpha > 0.80 in all scales). The empirical factor structure was generally consistent with the theoretical factor structure and supported construct validity. The Family Impact Module discriminated between parents of children with severe sickle cell disease from parents of children with mild disease or no disease in the areas of communication and worry. There were no significant differences across any of the subscales between parents of children with mild sickle cell disease and those with no disease. Parents with higher scores, representing better HRQL and family functioning, generally reported higher HRQL scores for their children.</p> <p>Conclusion</p> <p>The PedsQL™ Family Impact module was reliable, however it displayed large ceiling effects and did not discriminate well between parents of children with and without sickle cell disease. Future research to evaluate the psychometric properties of the Family Impact Module for parents of healthy children may be helpful.</p
Quantification of the Individual Characteristics of the Human Dentition
The considerations for admissibility suggested by the Daubert trilogy challenge forensic experts to provide scientific support for opinion testimony. The defense bar has questioned the reliability of bitemark analysis. Under an award from the U. S. Department of Justice, via the Midwest Forensic Resource Center, a two-year feasibility study was undertaken to quantify six dental characteristics. Using two computer programs, the exemplars of 419 volunteers were digitally scanned, characteristics were measured, and frequency was calculated. The study demonstrates that there were outliers or rare dental characteristics in measurements. An analysis of the intra-observer and inter-observer consistency demonstrated a high degree of agreement. Expansion of the sample size through collaboration with other academic researchers will be necessary to be able to quantify the occurrence of these characteristics in the general population. The automated software application, Tom\u27s Toolbox, developed specifically for this research project, could also provide a template for precisely quantifying other pattern evidence
Socio-demographics of Adult Orthodontic Visits in the United States
Introduction: Population-based studies in orthodontics have focused on differences between normative and perceived needs. However, information from national data on the prevalence of orthodontic visits and their associated factors in adults in the United States is scarce. We examined the demographic profile of likely adult users of orthodontic services and whether there is racial and ethnic disparity in orthodontic visits. Methods: We analyzed data from the Medical Expenditure Panel Survey, 2000-2004. Results: Overall, about 1% of the population reported an orthodontic visit. Subjects who made a general dental visit during the current year were significantly more likely to also have an orthodontic visit. Single adults, women, people between 18 and 30 years of age, and those from high-income families were more likely to report an orthodontic visit. There were no indications of racial and ethnic disparity for either black or Hispanic adults compared with white adults after adjusting for other covariates. Conclusions: Substantial racial and ethnic disparity in adult orthodontic usage was not identified. Adults (ages 18-30 years), women, those with higher incomes, and single adults had significantly higher odds of reporting an orthodontic visit. However, additional studies specifically evaluating the association of treatment need among low-income families are required to evaluate whether these adults face significant barriers in accessing orthodontic care
Primary Language Spoken at Home and Children\u27s Dental Service Utilization in the United States
Objective: Language barriers have been well documented as a contributing factor to disparities in the receipt of medical services, especially for Hispanic children. However, there is a paucity of information on the effect of language barriers on children\u27s dental service utilization. We examined the association of primary language spoken at home with the receipt of preventive and routine dental care for children in the United States. Methods: We analyzed data from the Medical Expenditure Panel Survey (2002-2004), which contains data on 21,049 children weighted to represent 75.8 million children nationally. Results: Among children aged 1-18 years, 13 percent spoke a language other than English at home. Whites, females, children between the ages of 7 and 12 years, and those whose parents spoke English at home had the highest marginal rates of preventive and routine dental visits. However, the large marginal effect of language, even among Hispanics, was not significant after adjusting for other covariates. Parental education and having a primary provider were the strongest predictors of preventive and routine dental visits. Conclusion: Children that did not speak English at home were less likely to receive preventive or routine dental care. However, after adjusting for other socio-economic factors, our study suggests that language barriers may not play as pronounced a role in the receipt of dental care as that documented for medical services
Accelerated and interpretable oblique random survival forests
The oblique random survival forest (RSF) is an ensemble supervised learning
method for right-censored outcomes. Trees in the oblique RSF are grown using
linear combinations of predictors to create branches, whereas in the standard
RSF, a single predictor is used. Oblique RSF ensembles often have higher
prediction accuracy than standard RSF ensembles. However, assessing all
possible linear combinations of predictors induces significant computational
overhead that limits applications to large-scale data sets. In addition, few
methods have been developed for interpretation of oblique RSF ensembles, and
they remain more difficult to interpret compared to their axis-based
counterparts. We introduce a method to increase computational efficiency of the
oblique RSF and a method to estimate importance of individual predictor
variables with the oblique RSF. Our strategy to reduce computational overhead
makes use of Newton-Raphson scoring, a classical optimization technique that we
apply to the Cox partial likelihood function within each non-leaf node of
decision trees. We estimate the importance of individual predictors for the
oblique RSF by negating each coefficient used for the given predictor in linear
combinations, and then computing the reduction in out-of-bag accuracy. In
general benchmarking experiments, we find that our implementation of the
oblique RSF is approximately 450 times faster with equivalent discrimination
and superior Brier score compared to existing software for oblique RSFs. We
find in simulation studies that 'negation importance' discriminates between
relevant and irrelevant predictors more reliably than permutation importance,
Shapley additive explanations, and a previously introduced technique to measure
variable importance with oblique RSFs based on analysis of variance. Methods
introduced in the current study are available in the aorsf R package.Comment: 40 pages, 6 figure
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