Browsing by Author "Zhao, Shi"

Now showing 1 - 7 of 7
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    Acute Sport Concussion Assessment Optimization: A Prospective Assessment from the CARE Consortium
    (Springer, 2019) Broglio, Steven P.; Harezlak, Jaroslaw; Katz, Barry; Zhao, Shi; McAllister, Thomas; McCrea, Michael; Biostatistics, School of Public Health
    Background Numerous medical organizations recommend a multifaceted approach to the assessment of concussion occurring during sporting events. A number of tools are available to clinicians, with a wide breadth of sensitivity and specificity; however, little work has been done to evaluate the combined efficiency of these tools in concussed male and female athletes from a broad array of collegiate sports and with variable time from the pre-season baseline evaluation. Objective The aim of this study was to optimize the concussion assessment battery for application within the first 72 h of injury, and to identify the necessary baseline retesting frequency. Methods Between 2014 and 2017, a total of 1458 National Collegiate Athletic Association (NCAA) athletes sustaining 1640 diagnosed concussions completed a baseline assessment each year of the investigation and were evaluated up to three times within the first 72 h of injury using a standardized assessment protocol. Classification and regression tree analyses were implemented to identify the most efficient multifaceted assessment pathway to quantify concussion-related outcomes. Results were optimized for assessments occurring within 1 h post-injury, 1–24 h post-injury, and 24–72 h post-injury when using the raw post-injury assessment performance, difference scores from baseline evaluations occurring in the same year, and difference scores from baseline evaluations occurring the year prior. Results At each of the assessment time points, the analyses indicated that alone or in combination, a symptom evaluation, Balance Error Scoring System (BESS) scores collected on the firm surface, and Standardized Assessment of Concussion (SAC) total score offered the best overall performance when compared with pre-morbid performance captured in the same season. Optimized sensitivity of the multifaceted approach was 61% within 1 h of injury, 67% at the 1–24 h interval, and 55% at the 24–72 h interval when difference scores from the same-season baseline were available. Conclusions This investigation identified key concussion assessments in quantifying post-concussion performance among student athletes, that were maximized when same-season pre-morbid evaluations were available. Consistent with clinical recommendations, medical professionals should continue to focus on symptom reporting, postural control, and neurocognitive screening to support the clinical examination when making a concussion diagnosis.
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    Comparison of nonlinear curves and surfaces
    (Elsevier, 2020-10) Zhao, Shi; Bakoyannis, Giorgos; Lourens, Spencer; Tu, Wanzhu; Biostatistics, School of Public Health
    Estimation of nonlinear curves and surfaces has long been the focus of semiparametric and nonparametric regression analysis. What has been less studied is the comparison of nonlinear functions. In lower-dimensional situations, inference typically involves comparisons of curves and surfaces. The existing comparative procedures are subject to various limitations, and few computational tools have been made available for off-the-shelf use. To address these limitations, two modified testing procedures for nonlinear curve and surface comparisons are proposed. The proposed computational tools are implemented in an R package, with a syntax similar to that of the commonly used model fitting packages. An R Shiny application is provided with an interactive interface for analysts who do not use R. The new tests are consistent against fixed alternative hypotheses. Theoretical details are presented in an appendix. Operating characteristics of the proposed tests are assessed against the existing methods. Applications of the methods are illustrated through real data examples.
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    Correction to: Test-Retest Reliability and Interpretation of Common Concussion Assessment Tools: Findings from the NCAA-DoD CARE Consortium
    (Springer, 2018-07) Broglio, Steven P.; Katz, Barry P.; Zhao, Shi; McCrea, Michael; McAllister, Thomas; CARE Consortium Investigators; Biostatistics, School of Public Health
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    LncRNA AK054921 and AK128652 are potential serum biomarkers and predictors of patient survival with alcoholic cirrhosis
    (Wiley, 2017-08) Yang, Zhihong; Ross, Ruth A.; Zhao, Shi; Tu, Wanzhu; Liangpunsakul, Suthat; Wang, Li; Medicine, School of Medicine
    Background: Alcoholic liver disease (ALD) is one of the leading causes of chronic liver disease. Recent studies have demonstrated the roles of long noncoding RNAs (lncRNAs) in the pathogenesis of several disease processes. However, the roles of lncRNAs in patients with ALD remain unexplored. Methods: Global profiling for human lncRNAs from peripheral blood RNA was performed in a well characterized cohort of healthy controls (HC, n=4), excessive drinkers without liver diseases (ED, n=4), and those with alcoholic cirrhosis with different severities (AC, n=12). The expression of unique lncRNA signatures were validated in a separate cohort of HC (n=17), ED (n=19), AC (n=48), and human liver tissues with ALD (n=19). Results: Detailed analysis of plasma lncRNAs in AC subjects with different severities compared to HC identified 244 commonly up-regulated lncRNAs and 181 commonly down-regulated lncRNAs. We further validated top 20 most differentially up- and down-regulated lncRNAs in ED and AC as compared to HC and also determined the expression of selected lncRNAs in human liver tissues with or without AC. Among those lncRNAs, AK128652 and AK054921 were two of the most abundantly expressed lncRNAs in normal human plasma and liver, and their levels were significantly elevated in AC. The prognostic significance of AK128652 and AK054921 was determined in 48 subjects with AC; who were prospectively followed for 520 days. The expression of AK128652 and AK054921 was inversely associated with survival in patients with AC. Conclusions: LncRNAs AK054921 and AK128652 are potential biomarkers to predict the progression to ALD in those with excessive alcohol consumption and are predictors of survival with patients with alcoholic cirrhosis.
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    Return to play and risk of repeat concussion in collegiate football players: comparative analysis from the NCAA Concussion Study (1999–2001) and CARE Consortium (2014–2017)
    (BMJ, 2020) McCrea, Michael; Broglio, Steven P.; McAllister, Thomas; Zhou, Wenxian; Zhao, Shi; Katz, Barry P.; Kudela, Maria; Harezlak, Jaroslaw; Nelson, Lindsay D.; Meier, Timothy B.; Marshall, Stephen W.; Guskiewicz, Kevin; Psychiatry, School of Medicine
    Objective We compared data from the National Collegiate Athletic Association (NCAA) Concussion Study (1999–2001) and the NCAA-Department of Defense Concussion Assessment, Research and Education (CARE) Consortium (2014–2017) to examine how clinical management, return to play (RTP) and risk of repeat concussion in collegiate football players have changed over the past 15 years. Methods We analysed data on reported duration of symptoms, symptom-free waiting period (SFWP), RTP and occurrence of within-season repeat concussion in collegiate football players with diagnosed concussion from the NCAA Study (n=184) and CARE (n=701). Results CARE athletes had significantly longer symptom duration (CARE median=5.92 days, IQR=3.02–9.98 days; NCAA median=2.00 days, IQR=1.00–4.00 days), SFWP (CARE median=6.00 days, IQR=3.49–9.00 days; NCAA median=0.98 days, IQR=0.00–4.00 days) and RTP (CARE median=12.23 days, IQR=8.04–18.92 days; NCAA median=3.00 days, IQR=1.00–8.00 days) than NCAA Study athletes (all p<0.0001). In CARE, there was only one case of repeat concussion within 10 days of initial injury (3.7% of within-season repeat concussions), whereas 92% of repeat concussions occurred within 10 days in the NCAA Study (p<0.001). The average interval between first and repeat concussion in CARE was 56.41 days, compared with 5.59 days in the NCAA Study (M difference=50.82 days; 95% CI 38.37 to 63.27; p<0.0001). Conclusion Our findings indicate that concussion in collegiate football is managed more conservatively than 15 years ago. These changes in clinical management appear to have reduced the risk of repetitive concussion during the critical period of cerebral vulnerability after sport-related concussion (SRC). These data support international guidelines recommending additional time for brain recovery before athletes RTP after SRC.
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    Statistical comparisons for nonlinear curves and surfaces
    (2018-05-31) Zhao, Shi; Tu, Wanzhu; Bakoyannis, Giorgos; Lourens, Spencer; Song, Yiqing
    Estimation of nonlinear curves and surfaces has long been the focus of semiparametric and nonparametric regression. The advances in related model fitting methodology have greatly enhanced the analyst’s modeling flexibility and have led to scientific discoveries that would be otherwise missed by the traditional linear model analysis. What has been less forthcoming are the testing methods concerning nonlinear functions, particularly for comparisons of curves and surfaces. Few of the existing methods are carefully disseminated, and most of these methods are subject to important limitations. In the implementation, few off-the-shelf computational tools have been developed with syntax similar to the commonly used model fitting packages, and thus are less accessible to practical data analysts. In this dissertation, I reviewed and tested the existing methods for nonlinear function comparison, examined their operational characteristics. Some theoretical justifications were provided for the new testing procedures. Real data exampleswere included illustrating the use of the newly developed software. A new R package and a more user-friendly interface were created for enhanced accessibility.
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    Test-Retest Reliability and Interpretation of Common Concussion Assessment Tools: Findings from the NCAA-DoD CARE Consortium
    (Springer, 2018-05) Broglio, Steven P.; Katz, Barry P.; Zhao, Shi; McCrea, Michael; McAllister, Thomas; CARE Consortium Investigators; Biostatistics, School of Public Health
    BACKGROUND: Concussion diagnosis is typically made through clinical examination and supported by performance on clinical assessment tools. Performance on commonly implemented and emerging assessment tools is known to vary between administrations, in the absence of concussion. OBJECTIVE: To evaluate the test-retest reliability of commonly implemented and emerging concussion assessment tools across a large nationally representative sample of student-athletes. METHODS: Participants (n = 4874) from the Concussion Assessment, Research, and Education Consortium completed annual baseline assessments on two or three occasions. Each assessment included measures of self-reported concussion symptoms, motor control, brief and extended neurocognitive function, reaction time, oculomotor/oculovestibular function, and quality of life. Consistency between years 1 and 2 and 1 and 3 were estimated using intraclass correlation coefficients or Kappa and effect sizes (Cohen's d). Clinical interpretation guidelines were also generated using confidence intervals to account for non-normally distributed data. RESULTS: Reliability for the self-reported concussion symptoms, motor control, and brief and extended neurocognitive assessments from year 1 to 2 ranged from 0.30 to 0.72 while effect sizes ranged from 0.01 to 0.28 (i.e., small). The reliability for these same measures ranged from 0.34 to 0.66 for the year 1-3 interval with effect sizes ranging from 0.05 to 0.42 (i.e., small to less than medium). The year 1-2 reliability for the reaction time, oculomotor/oculovestibular function, and quality-of-life measures ranged from 0.28 to 0.74 with effect sizes from 0.01 to 0.38 (i.e., small to less than medium effects). CONCLUSIONS: This investigation noted less than optimal reliability for most common and emerging concussion assessment tools. Despite this finding, their use is still necessitated by the absence of a gold standard diagnostic measure, with the ultimate goal of developing more refined and sound tools for clinical use. Clinical interpretation guidelines are provided for the clinician to apply with a degree of certainty in application.