53 research outputs found
Conditional Concordance-Assisted Learning Under Matched Case-Control Design For Combining Biomarkers For Population Screening
Incorporating promising biomarkers into cancer screening practices for early-detection is increasingly appealing because of the unsatisfactory performance of current cancer screening strategies. The matched case-control design is commonly adopted in biomarker development studies to evaluate the discriminative power of biomarker candidates, with an intention to eliminate confounding effects. Data from matched case-control studies have been routinely analyzed by the conditional logistic regression, although the assumed logit link between biomarker combinations and disease risk may not always hold. We propose a conditional concordance-assisted learning method, which is distribution-free, for identifying an optimal combination of biomarkers to discriminate cases and controls. We are particularly interested in combinations with a clinically and practically meaningful specificity to prevent disease-free subjects from unnecessary and possibly intrusive diagnostic procedures, which is a top priority for cancer population screening. We establish asymptotic properties for the derived combination and confirm its favorable finite sample performance in simulations. We apply the proposed method to the prostate cancer data from the carotene and retinol efficacy trial (CARET)
A Double-Robust Test For High-Dimensional Gene Coexpression Networks Conditioning On Clinical information
It has been increasingly appealing to evaluate whether expression levels of two genes in a gene coexpression network are still dependent given samples\u27 clinical information, in which the conditional independence test plays an essential role. For enhanced robustness regarding model assumptions, we propose a class of double-robust tests for evaluating the dependence of bivariate outcomes after controlling for known clinical information. Although the proposed test relies on the marginal density functions of bivariate outcomes given clinical information, the test remains valid as long as one of the density functions is correctly specified. Because of the closed-form variance formula, the proposed test procedure enjoys computational efficiency without requiring a resampling procedure or tuning parameters. We acknowledge the need to infer the conditional independence network with high-dimensional gene expressions, and further develop a procedure for multiple testing by controlling the false discovery rate. Numerical results show that our method accurately controls both the type-I error and false discovery rate, and it provides certain levels of robustness regarding model misspecification. We apply the method to a gastric cancer study with gene expression data to understand the associations between genes belonging to the transforming growth factor β signaling pathway given cancer-stage information
Relationship Between Food Security, Nutrition Security, and Diabetes: the Role of Supplemental Nutrition assistance Program Participation
BACKGROUND: Inadequate nutrition and poor diet quality are associated with a heightened risk of diabetes. The connection between food insecurity measures and diabetes has been established, with evidence indicating that Supplemental Nutrition Assistance Program (SNAP) participation contributes to reductions in food insecurity. Recently developed nutrition security measures, defined as the ability to acquire healthful foods to prevent diseases, and their association with diabetes and SNAP participation are not yet understood.
OBJECTIVES: This study aimed to assess the relationship between food security and nutrition security in relation to diabetes overall and by SNAP participation and nutrition security as potential modifiers.
METHODS: Secondary data analysis of cross-sectional pilot study data collected from adults in 5 US states (N = 517). Logistic regression mixed models included moderation analysis and clustering effects by state to address site-level confounding.
RESULTS: Higher nutrition security scores among adults, after adjusting for confounders, were significantly associated with lower odds of diabetes risk (adjusted odds ratio = 0.59; 95% confidence interval: 0.40, 0.87;
CONCLUSIONS: This study sheds light on the early exploration of the intricate relationship between nutrition security and diabetes. The findings suggest that a higher nutrition security score, after adjusting for confounders, was significantly associated with lower odds of diabetes risk. Notably, there were statistically significant interaction effects in these associations based on SNAP participation
Assessing Predictive Discrimination Performance of Biomarkers in the Presence of Treatment-induced Dependent Censoring
In medical studies, some therapeutic decisions could lead to dependent censoring for the survival outcome of interest. This is exemplified by a study of paediatric acute liver failure, where death was subject to dependent censoring due to liver transplantation. Existing methods for assessing the predictive performance of biomarkers often pose the independent censoring assumption and are thus not applicable. In this work, we propose to tackle the dependence between the failure event and dependent censoring event using auxiliary information in multiple longitudinal risk factors. We propose estimators of sensitivity, specificity and area under curve, to discern the predictive power of biomarkers for the failure event by removing the disturbance of dependent censoring. Point estimation and inferential procedures were developed by adopting the joint modelling framework. The proposed methods performed satisfactorily in extensive simulation studies. We applied them to examine the predictive value of various biomarkers and risk scores for mortality in the motivating example
Prevalence and Concordance of oral and Genital Hpv By Sexual orientation among Us Men
The objective of our study was to describe oral and genital human papillomavirus (HPV) infection prevalence and concordance by sexual orientation among US men using a nationally representative sample. We conducted a retrospective cross-sectional analysis of the 2013-2016 National Health and Nutrition Examination Survey. The survey conducts a physical examination and collects oral rinse and genital swab specimens; demographic and health behaviors are self-reported. We used descriptive statistics and multivariate regression models to estimate HPV infection prevalence and the likelihood of HPV infection, respectively. All analyses were adjusted for National Health and Nutrition Examination Survey design and weights, and statistical significance was tested at a 2-sided P value of less than .05. Men who have sex with men had a statistically significantly higher prevalence of oral HPV (high-risk, 9-valent, 4-valent, and HPV 16 and 18), genital HPV (9-valent, 4-valent, and HPV 16 and 18), and concordant oral and genital HPV (high-risk and 9-valent) infections compared with heterosexual men. Improved HPV prevention among men is needed
Treating alcohol use disorder in U.S. veterans: The role of traumatic brain injury
Objective: The authors examined the efficacy of valproate to reduce relapse to heavy drinking among veterans with alcohol use disorder (AUD) and neuropsychiatric comorbidities and whether antecedent traumatic brain injury (TBI) or posttraumatic stress disorder (PTSD) affected treatment response. Methods: Participants were male veterans 18–60 years old with an AUD and no other substance use besides nicotine or cannabis. Sixty-two patients were randomly assigned to receive either valproate or naltrexone. Participants were evaluated at baseline and followed weekly for 24 weeks. All participants received standardized psychosocial interventions as well as treatment for coexistent psychiatric conditions. Results: During the follow-up period, nine study subjects in the naltrexone group and 14 in the valproate group relapsed to heavy drinking, but the difference did not reach statistical significance. Participants with a history of moderate to severe TBI were more likely to relapse to heavy drinking compared with those with no TBI (hazard ratio=4.834, 95% CI=1.103–21.194, p=0.033). PTSD status did not significantly affect outcome. Conclusions: Intensive outpatient programs are efficacious alternatives to treat AUD in veterans, although the role of pharmacological treatment is not completely elucidated. Glutamatergic agents appear to be less effective than opiate antagonists to prevent relapse to heavy drinking and to increase cumulative abstinence. Future studies should examine novel pharmacological and nonpharmacological options.Fil: Jorge, Ricardo E.. Baylor College of Medicine;Fil: Li, Ruosha. Baylor College of Medicine;Fil: Liu, Xiangyu. Baylor College of Medicine;Fil: McGavin, Jill K.. Baylor College of Medicine;Fil: Shorter, Daryl I.. Baylor College of Medicine;Fil: Acion, Laura. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Calculo. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Calculo; ArgentinaFil: Arndt, Stephan. University of Iowa; Estados Unido
Pimavanserin 34 mg at Bedtime for the Treatment of Insomnia in 6 Veterans With Posttraumatic Stress Disorder
Reimbursement For Hpv Vaccine Cost in the Private Sector: a Comparison across Specialties
The human papillomavirus (HPV) vaccine is the most expensive of all routinely recommended pediatric vaccines. Adequate cost reimbursement by 3rd-party payers is a critical enabling factor for clinicians to continue offering vaccines. This study found that net returns from HPV vaccine cost reimbursements are lowest for family physicians (5.08/dose). Furthermore, a $1 increment in return was associated with an increase in HPV vaccine doses administered (highest for family physicians; 0.08% per dollar). Reimbursement for HPV vaccine costs by private payers is adequate; however, return margins are small for non-pediatric specialties
Impact of Timing to initiate adjuvant therapy On Survival of Elderly Glioblastoma Patients Using the Seer-Medicare and National Cancer Databases
The optimal time to initiate adjuvant therapy (AT) in elderly patients with glioblastoma (GBM) remains unclear. We investigated the impact of timing to start AT on overall survival (OS) using two national-scale datasets covering elderly GBM populations in the United States. A total of 3159 and 8161 eligible elderly GBM patients were derived from the Surveillance, Epidemiology and End Results (SEER)-Medicare linked dataset (2004-2013) and the National Cancer Database (NCDB) (2004-2014), respectively. The intervals in days from the diagnosis to the initiation of AT were categorized based on two scenarios: Scenario I (quartiles), ≤ 15, 16-26, 27-37, and ≥ 38 days; Scenario II (median), \u3c 27, and ≥ 27 days. The primary outcome was OS. We performed the Kaplan-Meier and Cox proportional hazards regression methods for survival analysis. A sensitivity analysis was performed using Propensity Score Matching (PSM) method to achieve well-balanced characteristics between early-timing and delayed-timing in Scenario II. Improved OS was observed among patients who underwent resection and initiated AT with either a modest delay (27-37 days) or a longer delay (≥ 38 days) compared to those who received AT immediately (≤ 15 days) from both the SEER-Medicare dataset [adjusted hazard ratio (aHR) 0.74, 95% CI 0.64-0.84, P \u3c 0.001; and aHR 0.81, 95% CI 0.71-0.92, P = 0.002] and the NCDB (aHR 0.83, 95% CI 0.74-0.93, P = 0.001; and aHR 0.87, 95% CI 0.77-0.98, P = 0.017). The survival advantage is observed in delayed-timing group as well in Scenario II. For elderly patients who had biopsy only, improved OS was only detected in a longer delay (Scenario I: ≥ 38 days vs. ≤ 15 days) or the delayed-timing group (Scenario II: ≥ 27 days vs. \u3c 27 days) in the NCDB while no survival difference was seen in SEER-Medicare population. For the best timing to start AT in elderly GBM patients, superior survivals were observed among those who had craniotomy and initiated AT with a modest (27-37 days) or longer delays (≥ 38 days) following diagnosis using both the SEER-Medicare and NCDB datasets (Scenario I). Such survival advantage was confirmed when categorizing delayed-timing vs. early-timing with the cut-off at 27 day in both datasets (Scenario II). The increased likelihood of receiving delayed AT (≥ 27 days) was significantly associated with tumor resection (STR/GTR), years of diagnosis after 2006, African American and Hispanics races, treatments at academic facilities, and being referred. There is no difference in timing of AT on survival among elderly GBM patients who had biopsy in the SEER-Medicare dataset. In conclusion, initiating AT with a modest delay (27-37 days) or a longer delay (≥ 38 days) after craniotomy may be the preferred timing in the elderly GBM population
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