Ralph B. D'Agostino

Bio: Ralph B. D'Agostino is an academic researcher from Wake Forest University. The author has contributed to research in topics: Framingham Heart Study & Framingham Risk Score. The author has an hindex of 226, co-authored 1287 publications receiving 229636 citations. Previous affiliations of Ralph B. D'Agostino include VA Boston Healthcare System & University of Illinois at Urbana–Champaign.

The Power of Geary's test of normality

Abstract: SUMMARY The results of an extensive simulation study investigating the power of Geary's a test for normality are summarized. While there appears to be no specific situation where Geary's test clearly and for practical purposes dominates all other tests of normality, it still has good power properties. This coupled with its computational simplicity make it still a possibly useful test.

Relationship between plasma homocysteine, vitamin status and extracranial carotid-artery stenosis in the Framingham Study population : Homocyst(e)ine, vitamins and arterial occlusive diseases

Abstract: Recent studies demonstrated associations between occlusive vascular disease and hyperhomocysteinemia of both genetic and nutritional origin. In the present study we analyzed plasma samples from the 20th biannual examination of the Framingham Heart Study cohort to determine distribution of plasma homocysteine concentrations with emphasis on relationships to B vitamins and prevalence of carotid artery stenosis. Results showed that homocysteine exhibited strong inverse association with plasma folate and weaker associations with plasma vitamin B-12 and pyridoxal-5'-phosphate (PLP). Homocysteine was also inversely associated with intakes of folate and vitamin B-6, but not vitamin B-12. Prevalence of high homocysteine (>14 μmol/l) was 29.3% in this cohort, and inadequate plasma concentrations of one or more B vitamins appear to contribute to 67% of the cases of high homocysteine. Prevalence of stenosis ≥25% was 43% in men and 34% in women with an odds ratio of 2.0 for individuals in the highest homocysteine quartile (≥14.4 μmol/l) compared with those in the lowest quartile (≤9.1 μmol/l), after adjustment for sex, age, high density lipoprotein cholesterol, systolic blood pressure and cigarette smoking (P trend < 0.001). Plasma concentrations of folate and pyridoxal-5'-phosphate and folate intake were inversely associated with extracranial carotid stenosis after adjustment for age, sex and other risk factors.

A Model for Predicting Gastrostomy Tube Placement in Patients Undergoing Surgery for Upper Aerodigestive Tract Lesions

Abstract: Importance Identifying high-risk patients in the preoperative period can allow physicians to optimize nutritional status early for better outcomes after head and neck cancer resections. Objective To develop a model to predict preoperatively the need for gastrostomy tube (G-tube) placement in patients undergoing surgery of the upper aerodigestive tract. Design, Setting, and Participants This retrospective medical record review included all adult patients diagnosed with head and neck cancers who underwent tumor resection from 2007 through 2012 at Wake Forest Baptist Health, a level 1 tertiary care center. Records were screened for patient demographics, tumor characteristics, surgical treatment type, and postoperative placement of G-tube. A total of 743 patients underwent resection of head and neck tumors. Of these, 203 were excluded for prior G-tube placement, prior head and neck resection, G-tube placement for chemoradiotherapy, and resection for solely nodal disease, leaving 540 patients for analysis. Main Outcomes and Measures Placement of postoperative G-tube. Results Of the 540 included patients, 23% required G-tube placement. The following variables were significant and independent predictors of G-tube placement: preoperative irradiation (odds ratio [OR], 4.1; 95% CI, 2.4-6.9; P P P P = .01), clinical node stage N1 vs N2 (OR, 1.6; 95% CI, 0.8-3.3; P = .01), preoperative weight loss (OR, 2.0; 95% CI, 1.2-3.2; P = .004), dysphagia (OR, 2.0; 95% CI, 1.2-3.2; P = .005), reconstruction type (OR, 1.9; 95% CI, 1.1-2.9; P = .02), and tumor stage (OR, 1.8; 95% CI, 1.1-2.9; P = .03). A predictive model was developed based on these variables. In the validation analysis, we found that the average predicted score for patients who received G-tubes was statistically different than the score for the patients who did not receive G-tubes ( P = .01). Conclusions and Relevance We present a validated and comprehensive model for preoperatively predicting the need for G-tube placement in patients undergoing surgery of the upper aerodigestive tract. Early enteral access in high-risk patients may prevent complications in postoperative healing and improve overall outcomes, including quality of life.

A Note on the Use of Confidence Limits following Rejection of a Null Hypothesis

Abstract: The equivalence of some tests of hypothesis and confidence limits is well known. When, however, the confidence limits are computed only after rejection of a null hypothesis, the usual unconditional confidence limits are no longer valid. This refers to a strict two-stage inference procedure: first test the hypothesis of interest and if the test results in a rejection decision, then proceed with estimating the relevant parameter. Under such a situation, confidence limits should be computed conditionally on the specified outcome of the test under which estimation proceeds. Conditional confidence sets will be longer than unconditional confidence sets and may even contain values of the parameter previously rejected by the test of hypothesis. Conditional confidence limits for the mean of a normal population with known variance are used to illustrate these results. In many applications, these results indicate that conditional estimation is probably not good practice.

The elevated expression of a mismatch repair protein is a predictor for biochemical recurrence after radical prostatectomy.

Abstract: Purpose: The inability to predict clinical outcome of prostate cancer is a major impediment to effective treatment decisions and patient counseling. New markers of recurrence are needed to improve the accuracy of risk assessment and treatment of prostate cancer. Our previous studies identified a mismatch repair protein, PMS2, to be elevated in prostate cancer; here, we investigate the prognostic potential of this marker. We hypothesized that the elevation of PMS2 would correlate with disease outcome. Experimental Design: Retrospective quantitative immunohistochemistry was done to measure PMS2 in high-grade cancers of 166 men treated by radical prostatectomy with a biochemical recurrence rate of 56%. Associations between PMS2 levels, pathologic variables, and biochemical recurrence over time were determined. Results: The mean level of PMS2 protein was consistently higher in both cancer-associated benign epithelium and cancer cells of patients who recurred, compared with nonrecurrent patients. PMS2 was an independent predictor of time-to-recurrence in Cox multivariate analyses and significantly stratified patients based on outcome. PMS2 was able to improve the sensitivity of total percent Gleason 4/5 as a risk factor for recurrence in this cohort. Conclusions: PMS2 protein levels were shown to be a predictor of time-to-recurrence after surgery. This study is the first to document that the elevation of a mismatch repair protein negatively correlates with prognosis and has implications in patient diagnosis and molecular profiling. (Cancer Epidemiol Biomarkers Prev 2009;18(1):57–64)

G*Power 3: A flexible statistical power analysis program for the social, behavioral, and biomedical sciences

Abstract: G*Power (Erdfelder, Faul, & Buchner, 1996) was designed as a general stand-alone power analysis program for statistical tests commonly used in social and behavioral research. G*Power 3 is a major extension of, and improvement over, the previous versions. It runs on widely used computer platforms (i.e., Windows XP, Windows Vista, and Mac OS X 10.4) and covers many different statistical tests of thet, F, and χ2 test families. In addition, it includes power analyses forz tests and some exact tests. G*Power 3 provides improved effect size calculators and graphic options, supports both distribution-based and design-based input modes, and offers all types of power analyses in which users might be interested. Like its predecessors, G*Power 3 is free.

The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report.

Abstract: "The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure" provides a new guideline for hypertension prevention and management. The following are the key messages(1) In persons older than 50 years, systolic blood pressure (BP) of more than 140 mm Hg is a much more important cardiovascular disease (CVD) risk factor than diastolic BP; (2) The risk of CVD, beginning at 115/75 mm Hg, doubles with each increment of 20/10 mm Hg; individuals who are normotensive at 55 years of age have a 90% lifetime risk for developing hypertension; (3) Individuals with a systolic BP of 120 to 139 mm Hg or a diastolic BP of 80 to 89 mm Hg should be considered as prehypertensive and require health-promoting lifestyle modifications to prevent CVD; (4) Thiazide-type diuretics should be used in drug treatment for most patients with uncomplicated hypertension, either alone or combined with drugs from other classes. Certain high-risk conditions are compelling indications for the initial use of other antihypertensive drug classes (angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, β-blockers, calcium channel blockers); (5) Most patients with hypertension will require 2 or more antihypertensive medications to achieve goal BP (<140/90 mm Hg, or <130/80 mm Hg for patients with diabetes or chronic kidney disease); (6) If BP is more than 20/10 mm Hg above goal BP, consideration should be given to initiating therapy with 2 agents, 1 of which usually should be a thiazide-type diuretic; and (7) The most effective therapy prescribed by the most careful clinician will control hypertension only if patients are motivated. Motivation improves when patients have positive experiences with and trust in the clinician. Empathy builds trust and is a potent motivator. Finally, in presenting these guidelines, the committee recognizes that the responsible physician's judgment remains paramount.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure

Abstract: The National High Blood Pressure Education Program presents the complete Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Like its predecessors, the purpose is to provide an evidence-based approach to the prevention and management of hypertension. The key messages of this report are these: in those older than age 50, systolic blood pressure (BP) of greater than 140 mm Hg is a more important cardiovascular disease (CVD) risk factor than diastolic BP; beginning at 115/75 mm Hg, CVD risk doubles for each increment of 20/10 mm Hg; those who are normotensive at 55 years of age will have a 90% lifetime risk of developing hypertension; prehypertensive individuals (systolic BP 120-139 mm Hg or diastolic BP 80-89 mm Hg) require health-promoting lifestyle modifications to prevent the progressive rise in blood pressure and CVD; for uncomplicated hypertension, thiazide diuretic should be used in drug treatment for most, either alone or combined with drugs from other classes; this report delineates specific high-risk conditions that are compelling indications for the use of other antihypertensive drug classes (angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, beta-blockers, calcium channel blockers); two or more antihypertensive medications will be required to achieve goal BP (<140/90 mm Hg, or <130/80 mm Hg) for patients with diabetes and chronic kidney disease; for patients whose BP is more than 20 mm Hg above the systolic BP goal or more than 10 mm Hg above the diastolic BP goal, initiation of therapy using two agents, one of which usually will be a thiazide diuretic, should be considered; regardless of therapy or care, hypertension will be controlled only if patients are motivated to stay on their treatment plan. Positive experiences, trust in the clinician, and empathy improve patient motivation and satisfaction. This report serves as a guide, and the committee continues to recognize that the responsible physician's judgment remains paramount.