Evaluating real-time probabilistic forecasts with application to National Basketball Association outcome prediction

Motivated by the goal of evaluating real-time forecasts of home team win probabilities in the National Basketball Association, we develop new tools for measuring the quality of continuously updated probabilistic forecasts. This includes introducing calibration surface plots, and simple graphical summaries of them, to evaluate at a glance whether a given continuously updated probability forecasting method is well-calibrated, as well as developing statistical tests and graphical tools to evaluate the skill, or relative performance, of two competing continuously updated forecasting methods. These tools are studied by means of a Monte Carlo simulation study of simulated basketball games, and demonstrated in an application to evaluate the continuously updated forecasts published by the United States-based multinational sports network ESPN on its principle webpage {\tt espn.com}. This application lends statistical evidence that the forecasts published there are well-calibrated, and exhibit improved skill over several na\"ive models, but do not demonstrate significantly improved skill over simple logistic regression models based solely on a measurement of each teams' relative strength, and the evolving score difference throughout the game

The acute-phase response varies with time and predicts serum albumin levels in hemodialysis patients

The acute-phase response varies with time and predicts serum albumin levels in hemodialysis patients.BackgroundCross sectional studies have established that the serum albumin level is dependent on serum levels of acute-phase proteins (APPs) or cytokine levels in hemodialysis patients. While the acute-phase response is generally associated with acute inflammatory events, a cross sectional analysis relating laboratory values to outcomes assumes these values to be unchanging. The longitudinal relationship among laboratory measurements and how they vary over time in a population of patients are unknown.MethodsPatients who were enrolled in the HEMO Study were recruited into an ancillary longitudinal study to establish the predictive effect of temporal variation in the levels of APPs and of temporal variation in normalized protein catabolic rate (nPCR) on the serum albumin concentration. nPCR was measured monthly using a double-pool method. The positive APPs—C-reactive protein (CRP), α1 acid glycoprotein (α1-AG), and ceruloplasmin—and the negative APP—transferrin (Trf)—were measured in serum obtained before each dialysis session for six weeks and then monthly in 37 hemodialysis patients. A random coefficient regression analysis was used to assess the association of serum albumin with other measured parameters at each time point, as well as fixed patient characteristics.ResultsThe within-subject coefficients of variation of albumin (median, range of 25th to 75th percentiles; median, 0.0614; range, 0.0485 to 0.0690) were significantly less than that of APPs (CRP, median, 0.878; range, 0.595 to 1.314, P < 0.05; and α1 AG, median, 0.173; range, 0.116 to 0.247, P < 0.05). The levels of APPs and albumin varied considerably over time. The primary predictor of current albumin was the current CRP level (P = 0.0014). nPCR also was a significant predictor for albumin levels (P = 0.0440) after controlling for the effect of APPs, suggesting an effect of nPCR on serum albumin concentration irrespective of the acute-phase response. Age and the presence of an arteriovenous graft were significant predictors that were associated with reduced albumin.ConclusionsThe acute-phase response is intermittent and is not a continuous feature in individual dialysis patients. Levels of APPs are the most powerful predictors for the levels of albumin concentration in hemodialysis in a longitudinal setting. Since variations in albumin are small, measurement of variations in APPs may provide greater insight into the dynamics of clinically relevant processes

The Value of Admission Clinical Data for Diagnosing Heart Failure in Long-term Care

Background Heart failure (HF) is common in long-term care (LTC). Diagnostic uncertainty is important barrier to optimal HF management, stemming from inadequate health information transfer upon LTC admission. We determine the utility of admission clinical information to confirm a HF diagnosis in new LTC residents. Methods This was a prospective cohort study. From February 2004 to November 2006, information about new residents from 41 LTC homes in Ontario, Canada, was collected from residents and caregivers, and all available health records. A prior HF diagnosis was confirmed by consensus review of available data by two independent experts. Multivariate modelling was utilized to determine the utility of the admission clinical assessment in confirming a prior HF diagnosis. Results A total of 449 residents were included for analysis, aged84.3±6.5 years, and 21.6% had a prior HF diagnosis. The most useful clinical item for diagnosing HF was a “history of HF”. The final model included “history of HF’ (OR [odds ratio] 13.66, 95% CI 6.61–28.24), “fluid on the lungs” (OR 2.01, 95% CI 1.04–3.89), “orthopnea” (OR 1.76, 95% CI 0.93–3.33), “taking β-blocker” (OR 2.09, 95% CI 1.10– 3.94), “taking loop diuretics” (OR 2.11, 95% CI 1.12–3.98), and “history of coronary artery disease” (OR 2.83, 95% CI 1.42–5.64). Conclusion Elements of the clinical assessment for new LTC residents can help confirm a prior HF diagnosis. An admission history of HF is highly predictiveCanadian Institutes of Health Research (CIHR; Study ID 117947-BCA-CEBA-126289

A longitudinal evaluation of food safety knowledge and attitudes among Ontario high school students following a food handler training program

The final publication is available at Elsevier via https://doi.org/10.1016/j.foodcont.2017.01.011 © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Youth are a unique audience for food safety education, in part due to low food safety knowledge. Although the effectiveness of such education has been explored for primary school and college students, no studies have assessed effectiveness among high school students specifically. We conducted a longitudinal intervention study in Ontario, Canada, between February and May 2015, to measure the baseline food safety knowledge and attitudes of high school students (n=119; from 8 classes in 4 high schools), and determine whether these factors improved following in-class delivery of a provincial standardized food handler training program. Linear mixed effects regression models were used to model within-student changes in knowledge scores and attitudes over time (i.e., circa 2 and 12 weeks post-intervention), and to investigate associations with student characteristics. At baseline, knowledge and attitudes were poor. Following training, overall knowledge was significantly greater than at baseline, although at three months post-intervention only knowledge of safe times and temperatures for cooking and storing food remained significantly higher than baseline. Following training, students were significantly less interested in learning about how to avoid foodborne disease. Other attitudes, as well as knowledge of cross-contamination prevention and disinfection procedures, remained unchanged. These findings suggest that delivering existing food handler training programs within high schools may be a feasible mechanism for food safety educators to improve students’ food safety knowledge, both overall and specific to safe times and temperatures, albeit potentially for short timeframes. Whether knowledge continues to decline beyond three months after training bears further investigation. As well, future research to investigate how students’ actual food safety practices may change following such training, and whether improvements in knowledge translate into reduced foodborne disease risk, is warranted.Ontario Ministry of Agriculture, Food and Rural Affairs' Food Safety Research Program || FS2013-1843 Canadian Institutes of Health Research || OOP-110788 Canadian Institutes of Health Research || MOP-114875 Additional support was provided via CIHR Public Health Agency of Canada Chairs in Applied Public Health (D. Hammond, S. Leatherdale)

Principal component analysis of dietary and lifestyle patterns in relation to risk of subtypes of esophageal and gastric cancer

Purpose To carry out pattern analyses of dietary and lifestyle factors in relation to risk of esophageal and gastric cancers. Methods We evaluated risk factors for esophageal adenocarcinoma (EA), esophageal squamous cell carcinoma (ESCC), gastric cardia adenocarcinoma (GCA), and other gastric cancers (OGA) using data from a population-based case-control study conducted in Connecticut, New Jersey, and western Washington state. Dietary/lifestyle patterns were created using principal component analysis (PCA). The impact of the resultant scores on cancer risk was estimated through logistic regression. Results PCA identified six patterns: meat/nitrite, fruit/vegetable, smoking/alcohol, legume/meat alternate, GERD/BMI, and fish/vitamin C. Risk of each cancer under study increased with rising meat/nitrite score. The risk of EA increased with increasing GERD/BMI score, and the risk of ESCC rose with increasing smoking/alcohol score and decreasing gastroesophageal reflux disease (GERD)/body mass index (BMI) score. Fruit/vegetable scores were inversely associated with EA, ESCC, and GCA. Conclusions PCA may provide a useful approach for summarizing extensive dietary/lifestyle data into fewer interpretable combinations that discriminate between cancer cases and controls. The analyses suggest that meat/nitrite intake is associated with an elevated risk of each cancer under study, whereas fruit/vegetable intake reduces the risk of EA, ESCC, and GCA. GERD/obesity was confirmed as risk factors for EA and smoking/alcohol as risk factors for ESCC

Diet and lifestyle factors and risk of subtypes of esophageal and gastric cancers: classification tree analysis

Although risk factors for squamous cell carcinoma of the esophagus (SCC) and adenocarcinomas of the esophagus (EA), gastric cardia (GC) and other (non-cardia) gastric sites (OG) have been identified, little is known about interactions among risk factors. We sought to examine interactions of diet, other lifestyle, and medical factors with risks of subtypes of esophageal and gastric cancer

Principal Component Analysis of Dietary and Lifestyle Patterns in Relation to Risk of Subtypes of Esophageal and Gastric Cancer

To perform pattern analyses of dietary and lifestyle factors in relation to risk of esophageal and gastric cancers