Scott W. Keith

Dr. Scott W. Keith

orcid

Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 August 2010 in International Journal of Obesity
Verified
Journal Article
Open access
PDF file
SKScott W. Keith
Scott W. Keith
KFK R Fontaine
K R Fontaine
NPN M Pajewski
N M Pajewski
TMT Mehta
T Mehta
DAD B Allison
D B Allison
Background: Many large-scale epidemiological data sources used to evaluate the body mass index (BMI: kg/m2) mortality association have relied on BMI derived from self-reported height and weight. Although measured BMI (BMIM) and self-reported BMI (BMISR) correlate highly, self-reports are systematically biased. Objective: To rigorously examine how self-reporting bias influences the association between BMI and mortality rate. Subjects: Samples representing the US non-institutionalized civilian population. Design and Methods: National Health and Nutrition Examination Survey data (NHANES II: 1976–80; NHANES III: 1988–94) contain BMIM and BMISR. We applied Cox regression to estimate mortality hazard ratios (HRs) for BMIM and BMISR categories, respectively, and compared results. We similarly analyzed subgroups of ostensibly healthy never-smokers. Results: Misclassification by BMISR among the underweight and obesity ranged from 30–40% despite high correlations between BMIM and BMISR (r>0.9). The reporting bias was moderately correlated with BMIM (r>0.35), but not BMISR (r<0.15). Analyses using BMISR failed to detect six of eight significant mortality HRs detected by BMIM. Significantly biased HRs were detected in the NHANES II full data set (χ2=12.49; P=0.01) and healthy subgroup (χ2=9.93; P=0.04), but not in the NHANES III full data set (χ2=5.63; P=0.23) or healthy subgroup (χ2=1.52; P=0.82). Conclusions: BMISR should not be treated as interchangeable with BMIM in BMI mortality analyses. Bias and inconsistency introduced by using BMISR in place of BMIM in BMI mortality estimation and hypothesis tests may account for important discrepancies in published findings.

27 July 2021 in Circulation
Verified
Journal Article
Closed access
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AAAndrew Althouse
Andrew Althouse
JBJennifer E. Below
Jennifer E. Below
BCBrian L. Claggett
Brian L. Claggett
NCNancy J. Cox
Nancy J. Cox
JLJames A. de Lemos
James A. de Lemos
OFon behalf of the American Heart Association Scientific Publishing Committee Statistics Task Force
on behalf of the American Heart Association Scientific Publishing Committee Statistics Task Force
Statistical analyses are a crucial component of the biomedical research process and are necessary to draw inferences from biomedical research data. The application of sound statistical methodology is a prerequisite for publication in the American Heart Association (AHA) journal portfolio. The objective of this document is to summarize key aspects of statistical reporting that might be most relevant to the authors, reviewers, and readership of AHA journals. The AHA Scientific Publication Committee convened a task force to inventory existing statistical standards for publication in biomedical journals and to identify approaches suitable for the AHA journal portfolio. The experts on the task force were selected by the AHA Scientific Publication Committee, who identified 12 key topics that serve as the section headers for this document. For each topic, the members of the writing group identified relevant references and evaluated them as a resource to make the standards summarized herein. Each section was independently reviewed by an expert reviewer who was not part of the task force. Expert reviewers were also permitted to comment on other sections if they chose. Differences of opinion were adjudicated by consensus. The standards presented in this report are intended to serve as a guide for high-quality reporting of statistical analyses methods and results.

1 August 2014 in Best Practice & Research Clinical Gastroenterology
Verified
Journal Article
Closed access
EDEmily J. Dhurandhar
Emily J. Dhurandhar
SKScott W. Keith
Scott W. Keith

7 February 2022 in BMC Cancer
Verified
Journal Article
Open access
PDF file
SKScott W. Keith
Scott W. Keith
VMVittorio Maio
Vittorio Maio
HAHwyda A. Arafat
Hwyda A. Arafat
MAMatthew Alcusky
Matthew Alcusky
TKThomas Karagiannis
Thomas Karagiannis
DLDaniel Z. Louis
Daniel Z. Louis
Background: Pancreatic cancer (PC) is one of the most aggressive and challenging cancer types to effectively treat, ranking as the fourth-leading cause of cancer death in the United States. We investigated if exposures to angiotensin II receptor blockers (ARBs) or angiotensin I converting enzyme (ACE) inhibitors after PC diagnosis are associated with survival. Methods: PC patients were identified by ICD-9 diagnosis and procedure codes among the 3.7 million adults living in the Emilia-Romagna Region from their administrative health care database containing patient data on demographics, hospital discharges, all-cause mortality, and outpatient pharmacy prescriptions. Cox modeling estimated covariate-adjusted mortality hazard ratios for time-dependent ARB and ACE inhibitor exposures after PC diagnosis. Results: 8,158 incident PC patients were identified between 2003 and 2011, among whom 20% had pancreas resection surgery, 36% were diagnosed with metastatic disease, and 7,027 (86%) died by December 2012. Compared to otherwise similar patients, those exposed to ARBs after PC diagnosis experienced 20% lower mortality risk (HR=0.80; 95% CI: 0.72, 0.89). Those exposed to ACE inhibitors during the first three years of survival after PC diagnosis experienced 13% lower mortality risk (HR=0.87; 95% CI: 0.80, 0.94) which attenuated after surviving three years (HR=1.14; 95% CI: 0.90, 1.45). Conclusions: The results of this large population study suggest that exposures to ARBs and ACE inhibitors after PC diagnosis are significantly associated with improved survival. ARBs and ACE inhibitors could be important considerations for treating PC patients, particularly those with the worst prognosis and most limited treatment options. Considering that these common FDA approved drugs are inexpensive to payers and present minimal increased risk of adverse events to patients, there is an urgent need for randomized clinical trials, large simple randomized trials, or pragmatic clinical trials to formally and broadly evaluate the effects of ARBs and ACE inhibitors on survival in PC patients.

26 August 2021 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
ASAlexander Smith
Alexander Smith
DJDrew Johnson
Drew Johnson
JBJoshua Banks
Joshua Banks
SKScott W. Keith
Scott W. Keith
DKDean G. Karalis
Dean G. Karalis
Background: Proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors reduce low-density lipoprotein (LDL) cholesterol and cardiovascular event rates, yet due to their high price remain underutilized and difficult to prescribe in clinical practice. In March 2018, their price was significantly reduced. We evaluated whether the price reduction would improve prescribing patterns of PCSK9 inhibitors in eligible patients with atherosclerotic cardiovascular disease (ASCVD). Methods: We identified the number of eligible ASCVD patients and those prescribed a PCSK9 inhibitor for each year between July 2015 and December 2019. Patient demographics and clinical characteristics for those prescribed a PCSK9 inhibitor were extracted from their electronic health record. Results: In total 1059 patients of eligible patients received a new prescription for a PCSK9 inhibitor. From 2015 to 2019, the rate of new prescriptions among eligible patients increased from 0.5 to 3.3% (p < 0.001) and continuation rates increased from 18 to 60% (p < 0.001). Following the price reduction, patients who were prescribed a PCSK9 inhibitor were younger and more likely to be female, but less likely to have Medicare insurance. Conclusions: Despite the reduction in the cost of PCSK9 inhibitors, most eligible patients are not prescribed one. The reduction in cost has improved adherence, primarily in patients with commercial insurance. Older patients and those on Medicare still face significant barriers in accessing a PCSK9 inhibitor. Further reductions in the price of the PCSK9 inhibitors are needed as is further study of the barriers that exist in prescribing one.

1 October 2023 in Radiology
Verified
Journal Article
Closed access
ESEsika Savsani
Esika Savsani
CSColette M. Shaw
Colette M. Shaw
FFFlemming Forsberg
Flemming Forsberg
CWCorinne E. Wessner
Corinne E. Wessner
ALAndrej Lyshchik
Andrej Lyshchik
John EisenbreyJohn Eisenbrey
John Eisenbrey
Background Contrast-enhanced (CE) US has been studied for use in the detection of residual viable hepatocellular carcinoma (HCC) after locoregional therapy, but multicenter data are lacking. Purpose To compare two-dimensional (2D) and three-dimensional (3D) CE US diagnostic performance with that of CE MRI or CT, the current clinical standard, in the detection of residual viable HCC after transarterial chemoembolization (TACE) in a prospective multicenter trial. Materials and Methods Participants aged at least 21 years with US-visible HCC scheduled for TACE were consecutively enrolled at one of three participating academic medical centers from May 2016 to March 2022. Each underwent baseline 2D and 3D CE US before TACE, 2D and 3D CE US 1-2 weeks and/or 4-6 weeks after TACE, and CE MRI or CT 4-6 weeks after TACE. CE US and CE MRI or CT were evaluated by three fellowship-trained radiologists for the presence or absence of viable tumors and were compared with reference standards of pathology (18%), angiography on re-treatment after identification of residual disease at 1-2-month follow-up imaging (31%), 4-8-month CE MRI or CT (42%), or short-term (approximately 1-2 months) CE MRI or CT if clinically decompensated and estimated viability was greater than 50% at imaging (9%). Diagnostic performance criteria, including sensitivity and specificity, were obtained for each modality and time point with generalized estimating equation analysis. Results A total of 132 participants were included (mean age, 64 years ± 7 [SD], 87 male). Sensitivity of 2D CE US 4-6 weeks after TACE was 91% (95% CI: 84, 95), which was higher than that of CE MRI or CT (68%; 95% CI: 58, 76; P < .001). Sensitivity of 3D CE US 4-6 weeks after TACE was 89% (95% CI: 81, 94), which was higher than that of CE MRI or CT (P < .001), with no evidence of a difference from 2D CE US (P = .22). CE MRI or CT had 85% (95% CI: 76, 91) specificity, higher than that of 4-6-week 2D and 3D CE US (70% [95% CI: 56, 80] and 67% [95% CI: 53, 78], respectively; P = .046 and P = .023, respectively). No evidence of differences in any diagnostic criteria were observed between 1-2-week and 4-6-week 2D CE US (P > .21). Conclusion The 2D and 3D CE US examinations 4-6 weeks after TACE revealed higher sensitivity in the detection of residual HCC than CE MRI or CT, albeit with lower specificity. Importantly, CE US performance was independent of follow-up time. Clinical trial registration no. NCT02764801 © RSNA, 2023 Supplemental material is available for this article.