115 research outputs found

    A note on the transitive Hurwitz action on decompositions of parabolic Coxeter elements

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    In this note, we provide a short and self-contained proof that the braid group on n strands acts transitively on the set of reduced factorizations of a Coxeter element in a Coxeter group of finite rank n into products of reflections. We moreover use the same argument to also show that all factorizations of an element in a parabolic subgroup of W lie as well in this parabolic subgroup.Comment: 5 page

    The SPADE Symptom Cluster in Primary Care Patients with Chronic Pain

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    Objectives: Sleep disturbance, pain, anxiety, depression, and low energy/fatigue, the SPADE pentad, are the most prevalent and co-occurring symptoms in the general population and clinical practice. Co-occurrence of SPADE symptoms may produce additive impairment and negatively affect treatment response, potentially undermining patients’ health and functioning. The purpose of this paper is to determine: (1) prevalence and comorbidity (ie, clustering) of SPADE symptoms; (2) internal reliability and construct validity of a composite SPADE symptom score derived from the Patient-Reported Outcomes Measurement Information System (PROMIS) measures; and (3) whether improvement in somatic symptom burden represented by a composite score predicted subsequent measures of functional status at 3 and 12 months follow-up. Methods: Secondary analysis of data from the Stepped Care to Optimize Pain care Effectiveness study, a randomized trial of a collaborative care intervention for Veterans with chronic pain. Results: Most patients had multiple SPADE symptoms; only 9.6% of patients were monosymptomatic. The composite PROMIS symptom score had good internal reliability (Cronbach’s alpha=0.86) and construct validity and strongly correlated with multiple measures of functional status; improvement in the composite score significantly correlated with higher scores for 5 of 6 functional status outcomes. The standardized error of measurement (SEM) for the composite T-score was 2.84, suggesting a 3-point difference in an individual’s composite score may be clinically meaningful. Discussion: Brief PROMIS measures may be useful in evaluating SPADE symptoms and overall symptom burden. Because symptom burden may predict functional status outcomes, better identification and management of comorbid symptoms may be warranted

    Does a Crossover Age Effect Exist for African American and Hispanic Binge Drinkers? Findings from the 2010 to 2013 National Study on Drug Use and Health

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    BACKGROUND: Among general population studies, lower rates of binge drinking tend to be found among African Americans and Hispanics compared to Whites. However, among older adult populations, minority groups have been shown to be at higher risk for binge drinking, suggesting the presence of a crossover effect from low to high risk as a function of age. To date, limited research has examined the crossover effect among African American and Hispanic populations compared to non-Hispanic Whites across large developmental time frames or explored variation in risk based on income or gender. This study aimed to fill these gaps in the literature. METHODS: Data were compiled from the 2010 to 2013 National Survey on Drug Use and Health surveys, which provide annual, nationally representative data on substance use behaviors among individuals aged 12 and older. Hispanic, non-Hispanic African American, and non-Hispanic White respondents were included (N = 205,198) in the analyses. RESULTS: A crossover effect was found for African American males and females among the lowest income level (i.e., incomes less than $20,000). Specifically, after controlling for education and marital status, compared to Whites, risk for binge drinking was lower for African American males at ages 18 to 24 and for females at ages 18 to 34, but higher for both African American males and females at ages 50 to 64. No crossover effect was found for Hispanic respondents. CONCLUSIONS: Although African Americans are generally at lower risk for binge drinking, risk appears to increase disproportionately with age among those who are impoverished. Explanatory factors, such as social determinants of health prevalent within low-income African American communities (e.g., lower education, violence exposure, housing insecurity) and potential areas for intervention programming are discussed

    Performance Characteristics of Fecal Immunochemical Tests for Colorectal Cancer and Advanced Adenomatous Polyps: A Systematic Review and Meta-analysis

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    Background: Studies report inconsistent performance of fecal immunochemical tests (FITs) for colorectal cancer (CRC) and advanced adenomas. Purpose: To summarize performance characteristics of FITs for CRC and advanced adenomas in average-risk persons undergoing screening colonoscopy (reference standard) and to identify factors affecting these characteristics. Data Sources: Ovid MEDLINE, PubMed, Embase, and the Cochrane Library from inception through October 2018; reference lists of studies and reviews. Study Selection: Two reviewers independently screened records to identify published English-language prospective or retrospective observational studies that evaluated FIT sensitivity and specificity for colonoscopic findings in asymptomatic, average-risk adults. Data Extraction: Two authors independently extracted data and evaluated study quality. Data Synthesis: Thirty-one studies (120 255 participants; 18 FITs) were included; all were judged to have low to moderate risk of bias. Performance characteristics depended on the threshold for a positive result. A threshold of 10 µg/g resulted in sensitivity of 0.91 (95% CI, 0.84 to 0.95) and a negative likelihood ratio of 0.10 (CI, 0.06 to 0.19) for CRC, whereas a threshold of greater than 20 µg/g resulted in specificity of 0.95 (CI, 0.94 to 0.96) and a positive likelihood ratio of 15.49 (CI, 9.82 to 22.39). For advanced adenomas, sensitivity was 0.40 (CI, 0.33 to 0.47) and the negative likelihood ratio was 0.67 (CI, 0.57 to 0.78) at 10 µg/g, and specificity was 0.95 (CI, 0.94 to 0.96) and the positive likelihood ratio was 5.86 (CI, 3.77 to 8.97) at greater than 20 µg/g. Studies had low to high heterogeneity, depending on the threshold. Although several FITs had adequate performance, sensitivity and specificity for CRC for 1 qualitative FIT were 0.90 and 0.91, respectively, at its single threshold of 10 µg/g; positive and negative likelihood ratios were 10.13 and 0.11, respectively. Comparison of 3 FITs at 3 thresholds was inconclusive: CIs overlapped, and the comparisons were across rather than within studies. Limitations: Only English-language studies were included. Incomplete reporting limited quality assessment of some evidence. Performance characteristics are for 1-time rather than serial testing. Conclusion: Single-application FITs have moderate to high sensitivity and specificity for CRC, depending on the positivity threshold. Sensitivity of 1-time testing for advanced adenomas is low, regardless of the threshold

    The Healthy Aging Brain Care (HABC) Monitor: validation of the Patient Self-Report Version of the clinical tool designed to measure and monitor cognitive, functional, and psychological health

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    BACKGROUND: Primary care providers need an inexpensive, simple, user-friendly, easily standardized, sensitive to change, and widely available multidomain instrument to measure the cognitive, functional, and psychological symptoms of patients suffering from multiple chronic conditions. We previously validated the Caregiver Report Version of the Healthy Aging Brain Care Monitor (HABC Monitor) for measuring and monitoring the severity of symptoms through caregiver reports. The purpose of this study was to assess the reliability and validity of the Patient Self-Report Version of the HABC Monitor (Self-Report HABC Monitor). DESIGN: Cross-sectional study. SETTING: Primary care clinics affiliated with a safety net urban health care system in Indianapolis, Indiana, USA. SUBJECTS: A total of 291 subjects aged ≥65 years with a mean age of 72.7 (standard deviation 6.2) years, 76% female, and 56% African Americans. ANALYSIS: Psychometric validity and reliability of the Self-Report HABC Monitor. RESULTS: Among 291 patients analyzed, the Self-Report HABC Monitor demonstrated excellent fit for the confirmatory factor analysis model (root mean square error of approximation =0.030, comparative fit index =0.974, weighted root mean square residual =0.837) and good internal consistency (0.78-0.92). Adequate convergent-divergent validity (differences between the Telephone Interview for Cognitive Status test-based cognitive function impairment versus nonimpairment groups) was demonstrated only when patients were removed from analysis if they had both cognitive function test impairment and suspiciously perfect self-report HABC Monitor cognitive floor scores of 0. CONCLUSION: The Self-Report HABC Monitor demonstrates good reliability and validity as a clinically practical multidimensional tool for measuring symptoms. The tool can be used along with its caregiver version to provide useful feedback (via monitoring of symptoms) for modifying care plans. Determining the validity of HABC Monitor scores from patients who self-report a perfect cognitive score of 0 requires cognitive function test results (eg, Telephone Interview for Cognitive Status or Mini Mental State Examination) or Caregiver Report HABC Monitor scores or further clinical examination to rule out the possibility that the patient is denying or unaware of their cognitive symptoms

    Applying Publicly Available Contextual Factors to Predict Smoking Relapse in a National Sample

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    Background: The ecological fallacy is broadly understood, though its complimentary problem, the individualistic or atomistic fallacy, isless often considered. Multilevel models offer the statistical tools needed to avoid both errors by allowing simultaneous considerationof individual, contextual, and policy factors. This study applies such methods to smoking cessation data. Tobacco control is of particularconcern in Ohio where the adult smoking prevalence remains around 22%.Methods: Data from the 1,785 participants in the Technology Enhanced Quitline Study were used to test the theory that contextualfactors impact relapse rates and program effectiveness, employing a mixed-effects model to account for the nested nature of the datawhile testing for the relationship between contextual factors and relapse, controlling for individual characteristics.Results: No contextual factors or policy variables were significant predictors of smoking relapse in the sample, nor were any associated with the success of the intervention.Conclusions: While this work could not identify specific influences of contextual and policy factors on smoking outcomes in our sample, it demonstrates the feasibility of adding such predictors to future clinical trials. This project clearly does not rule out the possibility that contextual and policy factors may influence smoking even after controlling for individual characteristics, but does not provide strong evidence of such a link. It is possible that these negative findings may be due to geocoded mailing addresses being a poor proxy for relevant contextual factors, use of the wrong geographic unit of analysis (modifiable areal unit problem), or a lack of temporal resolution in contextual variables

    Phenotypic features effectively stratify risk for advanced colorectal neoplasia in asymptomatic adults

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    poster abstractBackground: While colorectal cancer (CRC) screening is effective and cost-effective for reducing CRC incidence and mortality, it is underutilized (nearly 40% of U.S. adults are either not current with or have never been screened), inefficient (low-risk persons undergo colonoscopy), and costly to the U.S. health care system. A simple and effective way of stratifying risk for advanced neoplasia (AN – CRC and advanced, precancerous polyps) could improve the efficiency and uptake of screening by tailoring colonoscopy toward persons at highrisk and giving low-risk persons less-invasive options. Although several risk factors for AN have been identified, they are not used in clinical practice in part because of inability to integrate the factors to produce a risk estimate. Objective: To derive and validate a risk index for AN (CRC, advanced adenomas, serrated polyps >= 1 cm) anywhere in the colorectum. Methods: We measured socio-demographic features, medical and family history, lifestyle factors, and physical features in 50-80 year old persons who underwent first-time screening colonoscopy between December 2004 and September 2011, and linked these factors to endoscopic and histologic findings. Using logistic regression, we derived a risk equation on a randomly selected 2/3s of the sample. A 12-variable model was selected based on optimal statistical metrics. Based on model coefficients, we assigned points to each variable to create a risk score, which ranged from -13 to 8. Scores with comparable magnitudes of risk were collapsed into 3 risk categories. The model was tested on the remaining third of the sample. Results: Among 3025 subjects in the derivation set (mean age 57.3 ± 6.5 years; 52% women), the prevalence of AN was 9.4% (including 26 CRCs). Model variables include age, sex, smoking, ethanol use, marital status, NSAID and aspirin use, physical activity, education level, and metabolic syndrome (P-value for fit = 0.09; cstatistic=0.78). Respective risks of AN in the low- (scores of -13 to -5), intermediate- (scores of -4 to 2) and high- (scores of 3 to 12) were 1.52% (95%, 0.07-2.8%), 6.86%, and 26.8% (P-value for trend < 0.001), with respective cohort proportions of 23%, 59% and 18%. Ten low-risk subjects had AN (0 CRCs, 6 distal). Based on finding a distal sentinel polyp, sigmoidoscopy to the descending colon would have detected 7(70%) ANs. Among the 1475 subjects in the test set (mean age 57.2 ± 6.5 years; 52% women), AN prevalence was 8.4%. Risk of AN in the low-risk subgroup was 2.73% (CI, 1.25-5.11%) and was 5.57% and 25.4% in the intermediate- and high-risk subgroups, respectively (P<0.001), with cohort proportions of 23%, 59%, and 18%. Nine low-risk subjects had AN (0 CRCs, 5 distal, 6 detectable by sigmoidoscopy. Conclusion: This new risk index effectively stratifies the risk for AN among asymptomatic adults, identifying a low-risk subgroup of 23% that may be screened effectively and efficiently with tests other than colonoscopy and a high-risk subgroup of 18% in which colonoscopy may be preferable. If validated in other settings, this index could increase both the efficiency and uptake of CRC screening

    Impact of Tailored Interventions on Receipt of a Preference-Concordant Colorectal Cancer Screening Test

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    Background. Individuals at average risk for colorectal cancer (CRC) have multiple test options. Preference for a specific test modality may affect decision making about CRC screening. The current study examined 1) the sociodemographic and health belief characteristics of average-risk participants with a test preference for stool blood test (SBT) versus those with a preference of colonoscopy, and following receipt of a tailored CRC screening intervention, 2) the percentage of participants who completed a preference-concordant CRC screening test, and 3) the sociodemographic, health care experience, and health belief characteristics and intervention group(s) associated with completion of a preference-concordant screening test. Methods. Participants (N = 603) were female, aged 50 to 75 years, at average CRC risk, not currently up-to-date with CRC screening recommendations, had Internet access, and were randomized to receive 1 of 3 tailored CRC screening promotion interventions. Multivariable logistic regression analyses were conducted. Results. Most women (64%) preferred SBT, whereas 36% preferred colonoscopy. There were significant differences in test preference by age, stage of change for the specific tests, perceived benefits of CRC screening, perceived barriers to both tests, and self-efficacy for colonoscopy. Two hundred thirty participants completed CRC screening at 6 months post-intervention. Of those, most (84%) completed a test concordant with their preference. Multivariable analyses revealed that compared with participants completing a preference-discordant test, those completing a preference-concordant test were older (P = 0.01), had health insurance (P < 0.05), and were in the phone counseling-only group (P < 0.01). Conclusions. High levels of completion of preference-concordant CRC screening can be achieved by educating average-risk patients about the multiple screening test options, soliciting their preferences, and offering testing that is concordant with their preference

    Rasch Analysis, Dimensionality, and Scoring of the Neuropsychiatric Inventory Irritability and Aggression Subscales in Individuals With Traumatic Brain Injury

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    Objectives To develop, for versions completed by individuals with traumatic brain injury (TBI) and an observer, a more precise metric for the Neuropsychiatric Inventory (NPI) Irritability and Aggression subscales using all behavioral item ratings for use with individuals with TBI and to address the dimensionality of the represented behavioral domains. Design Rasch and confirmatory factor analyses of retrospective baseline NPI data from 3 treatment studies. Setting Postacute rehabilitation clinic. Participants NPI records (N = 525) consisting of observer ratings (n = 287) and self-ratings (n = 238) by participants with complicated mild, moderate, or severe TBI at least 6 months postinjury. Interventions Not applicable. Main Outcome Measures Frequency and severity ratings from NPI Irritability/Lability and Agitation/Aggression subscales. Results Confirmatory factor analyses of both observer and participant ratings showed good fit for either a 1-factor or a 2-factor solution. Consistent with this, the Rasch model also fit the data well with aggression items indicating the more severe end of the construct and irritability items populating the milder end. Conclusions Irritability and aggression appear to represent different levels of severity of a single construct. The derived Rasch metric offers a measure of this construct based on responses to all specific items that is appropriate for parametric statistical analysis and may be useful in research and clinical assessments of individuals with TBI
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