A method to approximate Bayesian posterior by evaluating it on a low discrepancy sequence (LDS) point set has recently been proposed. However, this method does not focus on finding the posterior ...marginals. Finding posterior marginals when the posterior approximation is obtained using LDS is not straightforward, and as yet, there is no method to approximate one dimensional marginals using an LDS. We propose an approximation method for this problem. This method is based on an s-dimensional integration rule together with fitting a polynomial smoothing function. We state and prove results showing conditions under which this polynomial smoothing function will converge to the true one-dimensional function. We also demonstrate the computational efficiency of the new approach compared to a grid based approach.
The characteristics of big data, including high volume, increased variety, and velocity, pose special challenges for data analysis. As these characteristics generally preclude manual data inspection ...and processing, researchers must often use computational methodologies to deal with this type of data; techniques that may be unfamiliar to nonspecialists, including behavioral scientists. However, previous data analytics methodologies within the field of computer science, developed to handle the generic tasks of data collection, preprocessing, and analysis, can be appropriated for use in other disciplines. These methodologies involve a sequential pipeline of quality checks to prepare data sets for analysis and application. Building upon these methodologies, this paper describes the Big Data Quality & Statistical Assurance (BDQSA) model, applicable for researchers in the behavioral sciences. It involves a series of data preprocessing tasks, to achieve data understanding, as well as data screening, cleaning, and transformation. These are followed by a statistical quality phase, which includes extraction of the relevant data subset, type conversions, ensuring sample representativeness when appropriate, and assessing statistical assumptions. The resulting model thereby provides methodological guidance for the preprocessing of behavioral science big data, aimed at ensuring acceptable data quality before analysis is undertaken. Sample R code snippets demonstrating the application of this model are provided throughout the paper.
Gambiense human African trypanosomiasis (gHAT) is a virulent disease declining in burden but still endemic in West and Central Africa. Although it is targeted for elimination of transmission by 2030, ...there remain numerous questions about the drivers of infection and how these vary geographically. In this study we focus on the Democratic Republic of Congo (DRC), which accounted for 84% of the global case burden in 2016, to explore changes in transmission across the country and elucidate factors which may have contributed to the persistence of disease or success of interventions in different regions. We present a Bayesian fitting methodology, applied to 168 endemic health zones (∼100,000 population size), which allows for calibration of a mechanistic gHAT model to case data (from the World Health Organization HAT Atlas) in an adaptive and automated framework. It was found that the model needed to capture improvements in passive detection to match observed trends in the data within former Bandundu and Bas Congo provinces indicating these regions have substantially reduced time to detection. Health zones in these provinces generally had longer burn-in periods during fitting due to additional model parameters. Posterior probability distributions were found for a range of fitted parameters in each health zone; these included the basic reproduction number estimates for pre-1998 (R0) which was inferred to be between 1 and 1.14, in line with previous gHAT estimates, with higher median values typically in health zones with more case reporting in the 2000s. Previously, it was not clear whether a fall in active case finding in the period contributed to the declining case numbers. The modelling here accounts for variable screening and suggests that underlying transmission has also reduced greatly-on average 96% in former Equateur, 93% in former Bas Congo and 89% in former Bandundu-Equateur and Bandundu having had the highest case burdens in 2000. This analysis also sets out a framework to enable future predictions for the country.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To update the Diagnosis-Specific Graded Prognostic Assessment (DS-GPA) for a markedly heterogeneous patient population, patients with melanoma and brain metastases, using a larger, more current ...cohort, including molecular markers.
The original Melanoma-GPA is based on data from 483 patients whose conditions were diagnosed between 1985 and 2005. This is a multi-institutional retrospective database analysis of 823 melanoma patients with newly diagnosed brain metastases from January 1, 2006, to December 31, 2015. Multivariable analyses identified significant prognostic factors, which were weighted and included in the updated index (Melanoma-molGPA). Multiple Cox regression was used to select and weight prognostic factors in proportion to their hazard ratios to design the updated Melanoma-molGPA in which scores of 4.0 and 0.0 are associated with the best and worst prognoses, as with all of the diagnosis-specific GPA indices. Log-rank tests were used to compare adjacent classes.
There were 5 significant prognostic factors for survival (age, Karnofsky performance status KPS, extracranial metastases ECM, number of brain metastases, and BRAF status), whereas only KPS and the number of brain metastases were significant in the original Melanoma-GPA. Median survival improved from 6.7 to 9.8 months between the 2 treatment eras, and the median survival times for patients with Melanoma-molGPA of 0 to 1.0, 1.5 to 2.0, 2.5 to 3.0, and 3.5 to 4.0 were 4.9, 8.3, 15.8, and 34.1 months (P<.0001 between each adjacent group).
Survival and our ability to estimate survival in melanoma patients with brain metastases has improved significantly. The updated Melanoma-molGPA, a user-friendly tool to estimate survival, will facilitate clinical decision making regarding whether and which treatment is appropriate and will also be useful for stratification of future clinical trials. To further simplify use, a free online/smart phone app is available at brainmetgpa.com.
To collect outcomes data on patients treated with a bioinductive collagen implant designed to induce rotator cuff healing in partial- and full-thickness cuff tears and to assess the safety and ...efficacy of the device.
Fifteen surgeons in 15 centers in the United States enrolled patients between April 2016 and August 2017 and collected standardized outcomes data. Patients 21 years of age and older, able to read and speak English, and with partial- or full-thickness tears of the rotator cuff documented by magnetic resonance imaging were included in the study. Patients were assessed preoperatively with visual analogue scale (VAS), single-assessment numeric evaluation (SANE), Veterans RAND 12-Item (VR-12), American Shoulder and Elbow Surgeons (ASES), and Western Ontario Rotator Cuff (WORC) outcomes measures. Postoperative assessment was made at 2, 6, and 12 weeks, 6 months, and 1 year. Patients underwent a standardized operative procedure with the implant. Patient demographics, comorbidities, tear types, and concomitant operative procedures were recorded.
Patients in both groups experienced statistically significant improvement in VAS, SANE, VR-12 PCS, ASES, and WORC scores (mean values 1.1, P < .001; 86.0, P < .001; 49.7, P < .001; 85.6, P < .001; and 84.4, P < .001 for partial tears and 1.2, P < .001; 80.7, P < .001; 45.7, P < .001; 83.8, P < .0001; and 80.1, P < .001 for full-thickness tears, respectively). For the partial tear group, average times for return to driving, work, and nonoverhead athletic activity were 14.6, 37.3, and 65.6 days, and for the full-thickness group, 24.5, 50.7, and 119.2 days, respectively. In the partial-thickness group, 84% and 83% of patients reported improvement in their VAS pain and ASES scores, respectively, that met or exceeded each measure's minimal clinically important difference. In the full-thickness group, 72% and 77% of the patients met or exceeded the minimal clinically important differences for VAS pain and ASES, respectively.
Outcomes after repair of partial- and full-thickness rotator cuff tears using a bioinductive implant show safety and efficacy at 1-year follow-up.
Retrospective case series, level IV evidence.
The diagnosis-specific Graded Prognostic Assessment (GPA) was published to clarify prognosis for patients with brain metastases. This study refines the existing Breast-GPA by analyzing a larger ...cohort and tumor subtype.
A multi-institutional retrospective database of 400 breast cancer patients treated for newly diagnosed brain metastases was generated. Prognostic factors significant for survival were analyzed by multivariate Cox regression and recursive partitioning analysis (RPA). Factors were weighted by the magnitude of their regression coefficients to define the GPA index.
Significant prognostic factors by multivariate Cox regression and RPA were Karnofsky performance status (KPS), HER2, ER/PR status, and the interaction between ER/PR and HER2. RPA showed age was significant for patients with KPS 60 to 80. The median survival time (MST) overall was 13.8 months, and for GPA scores of 0 to 1.0, 1.5 to 2.0, 2.5 to 3.0, and 3.5 to 4.0 were 3.4 (n = 23), 7.7 (n = 104), 15.1 (n = 140), and 25.3 (n = 133) months, respectively (p < 0.0001). Among HER2-negative patients, being ER/PR positive improved MST from 6.4 to 9.7 months, whereas in HER2-positive patients, being ER/PR positive improved MST from 17.9 to 20.7 months. The log-rank statistic (predictive power) was 110 for the Breast-GPA vs. 55 for tumor subtype.
The Breast-GPA documents wide variation in prognosis and shows clear separation between subgroups of patients with breast cancer and brain metastases. This tool will aid clinical decision making and stratification in clinical trials. These data confirm the effect of tumor subtype on survival and show the Breast-GPA offers significantly more predictive power than the tumor subtype alone.
Mitigating the spread of COVID-19 requires that people understand the need for and engage in protective behaviors. Given the complexity and rapid progression of media information about the pandemic, ...health literacy could be essential to acquiring the accurate beliefs, concern for societal risks, and appreciation of restrictive policies needed to motivate these behaviors. Yet with the increasingly politicized nature of COVID-related issues in the United States, health literacy could be an asset for those with more liberal views but less so for those with more conservative views.
This study tested a hypothesized model proposing that political views moderate the associations of health literacy with COVID-19 protective behaviors as well as the mediational roles of accurate and inaccurate COVID-19 beliefs, concern for society, and governmental control attitudes.
We surveyed residents in three diverse regions of California in June 2020 (N = 669) and February 2021 (N = 611). Participants completed measures of health literacy, political views, and COVID-19 beliefs and behaviors.
Moderated mediational analyses largely supported the proposed model with both samples. Health literacy was associated with more accurate COVID-19 beliefs, less inaccurate COVID-19 beliefs, greater concern for societal risks, more positive attitudes regarding restrictive government control, more protective behavior, less risky behavior, and stronger vaccine intentions; beliefs, concern for society, and governmental control attitudes mediated the health literacy-behavior relationships. As predicted, however, these associations of health literacy with adaptive beliefs, attitudes, and behaviors varied according to political views. The direct and mediated relationships were held for participants with more liberal views and, to a lesser extent, for those with moderate views, but they were weaker or absent for participants with more conservative views.
These findings contribute new evidence of processes linking health literacy with adaptive beliefs, attitudes, and behaviors and how social and political contexts can shape those processes.
•Health literacy was linked with more favorable COVID-related beliefs and behaviors.•Relationships of health literacy with these outcomes varied by political views.•Health literacy predicted outcomes primarily for those with more liberal views.
A prior Radiation Therapy Oncology Group (RTOG) clinical trial in anaplastic oligodendroglioma suggested a progression-free survival benefit for procarbazine, lomustine, and vincristine (PCV) ...chemotherapy in addition to radiation therapy (RT), as have smaller trials in low-grade glioma (LGG).
Eligibility criteria included supratentorial WHO grade 2 LGG, age 18 to 39 years with subtotal resection/biopsy, or age ≥ 40 years with any extent resection. Patients were randomly assigned to RT alone or RT followed by six cycles of PCV. Survival was compared by using the modified Wilcoxon and log-rank tests.
In all, 251 patients were accrued from 1998 to 2002. Median overall survival (OS) time and 5-year OS rates for RT versus RT + PCV were 7.5 years versus not reached and 63% versus 72%, respectively (hazard ratio HR; 0.72; 95% CI, 0.47 to 1.10; P = .33; log-rank P = .13). Median progression-free survival (PFS) time and 5-year PFS rates for RT versus RT + PCV were 4.4 years versus not reached and 46% versus 63%, respectively (HR, 0.6; 95% CI, 0.41 to 0.86; P = .06; log-rank P = .005). OS and PFS were similar for all patients between years 0 and 2. After 2 years, OS and PFS curves separated significantly, favoring RT + PCV. For 2-year survivors (n = 211), the probability of OS for an additional 5 years was 74% with RT + PCV versus 59% with RT alone (HR, 0.52; 95% CI, 0.30 to 0.90; log-rank P = .02).
PFS but not OS was improved for adult patients with LGG receiving RT + PCV versus RT alone. On post hoc analysis, for 2-year survivors, the addition of PCV to RT conferred a survival advantage, suggesting a delayed benefit for chemotherapy.
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