Steven Lauzon | Medical University of South Carolina (original) (raw)

Papers by Steven Lauzon

Statistical Methods in Medical Research

Minimization is among the most common methods for controlling baseline covariate imbalance at the... more Minimization is among the most common methods for controlling baseline covariate imbalance at the randomization phase of clinical trials. Previous studies have found that minimization does not preserve allocation randomness as well as other methods, such as minimal sufficient balance, making it more vulnerable to allocation predictability and selection bias. Additionally, minimization has been shown in simulation studies to inadequately control serious covariate imbalances when modest biased coin probabilities (≤0.65) are used. This current study extends the investigation of randomization methods to the analysis phase, comparing the impact of treatment allocation methods on power and bias in estimating treatment effects on a binary outcome using logistic regression. Power and bias in the estimation of treatment effect was found to be comparable across complete randomization, minimization, and minimal sufficient balance in unadjusted analyses. Further, minimal sufficient balance was ...

BMC Rheumatology

Background Patients with non-radiographic axial spondyloarthritis experience negative impacts on ... more Background Patients with non-radiographic axial spondyloarthritis experience negative impacts on sleep, work productivity, and activity impairment. Ixekizumab, a monoclonal antibody selectively targeting interleukin-17A, has shown efficacy in treating the signs and symptoms of non-radiographic axial spondyloarthritis. This analysis evaluated the effect of ixekizumab treatment on sleep, work productivity, and activity impairment in patients with non-radiographic axial spondyloarthritis. Methods COAST-X (NCT02757352) was a 52-week, phase 3, multicenter, randomised placebo-controlled trial evaluating 80-mg ixekizumab every 2 weeks and every 4 weeks in patients with active non-radiographic axial spondyloarthritis. Sleep disturbance was measured with the Jenkins Sleep Evaluation Questionnaire (JSEQ) and analysed using mixed-effects models for repeated measures. Work productivity and activity impairment were measured using the Work Productivity and Activity Impairment Questionnaire for Sp...

British Journal of Haematology

Individuals living with sickle cell disease (SCD) are at an increased risk of venous thrombo‐embo... more Individuals living with sickle cell disease (SCD) are at an increased risk of venous thrombo‐embolism (VTE) including pulmonary embolisms (PEs). There is a high mortality associated with PE in individuals with SCD. It can be difficult to diagnose PE since presenting symptoms of PE often mimic those of other forms of vaso‐occlusive crisis in SCD. Currently, there are no validated models for predicting PEs in patients with sickle cell disease, which often leads to frequent CT scans and exposure to harmful radiation and intravenous contrast. The aim of this study was to evaluate different host variables and potential clinical biomarkers of patients with SCD including those used in the Wells score to assess predictability for PE in order to create a more accurate diagnostic algorithm to predict PE. A retrospective chart review was performed on 349 patients with SCD who underwent testing for a PE with a CT scan of the chest. Forward and backward stepwise model selection was performed to obtain a parsimonious model of the predictors of PEs. The incidence of PE in this population was 9·7%. Of the factors evaluated for this study, the Wells score was the only one with clinical significance. A Wells score greater than 4 had a sensitivity and specificity of 72·5% and 70·1%, respectively, and a score greater than 6 had a sensitivity and specificity of 50% and 87%, respectively. The Wells score is an acceptable clinical tool which may prove useful in individuals with SCD to predict who is most likely to have a PE and therefore should undergo a CT scan. A prospective study is needed to further confirm these findings.

Pediatric Gastroenterology, Hepatology & Nutrition

Purpose: There have been many efforts to develop generalizable severity markers in children with ... more Purpose: There have been many efforts to develop generalizable severity markers in children with acute pancreatitis (AP). Expert opinion panels have developed consensus guidelines on management but it is unclear if these are sufficient or valid. Our study aims to assess the effect of clinical and laboratory variables, in addition to treatment modality on hospital length of stay (LOS) as a proxy variable for severity in pediatric patients admitted with AP. Methods: We conducted a retrospective chart review of patients between ages of 0-18 years, who were admitted with AP at 2 institutions between 2013-2018, John R. Oishei Children's Hospital (Buffalo, NY, USA) and Medical University of South Carolina Children's Hospital (Charleston, SC, USA). We constructed three linear regression models to analyze the effect of clinical signs of organ dysfunction, laboratory markers and fluid intake on hospital LOS. Results: Ninety-two patients were included in the study. The mean age was 12 years (range, 7.6-17.4 years), 55% were females, and median LOS was 3 days. The most frequent cause of AP was idiopathic. Our study showed that elevated blood urea nitrogen (BUN) on admission (p<0.005), tachycardia that lasted for ≥48 hours (p<0.001) and need for fluid resuscitation were associated with increase LOS. Total daily fluid intake above maintenance did not have a significant effect on the primary outcome (p=0.49). Conclusion: Elevated serum BUN on admission, persistent tachycardia and need for fluid resuscitation were associated with increase LOS in pediatric AP. Daily total fluid intake above recommended maintenance did not reduce LOS.

Journal of Genetic Counseling

As precision medicine becomes a mainstay in health care, the use of health information technology... more As precision medicine becomes a mainstay in health care, the use of health information technology (IT) platforms will play an important role in the delivery of services across the cancer care continuum. Currently, there is both limited understanding about perceptions of health IT tools and barriers to their use among cancer genetic counselors. We assessed open‐ended responses from a survey conducted among 128 board‐certified cancer genetic counselors in the United States. We evaluated the utility of ten health IT tools and perceived barriers to adoption. Responses about characteristics of health IT tools that influence current use (i.e., technology‐specific challenges) were deductively analyzed using the diffusion of innovations (DOI) characteristics. Responses about cancer genetic counselors' perceived challenges to adopting health IT tools (i.e., discipline‐specific challenges) were inductively coded using a thematic approach. DOI innovation characteristics included mixed perceptions about the relative advantage, complexity, compatibility, trialability, and observability of tools based on the type of tool and perceived end‐user. One‐third of participants indicated that they were considering adopting or switching health IT tools. Common barriers to adoption included no perceived need for change, lack of organizational infrastructure, cost, and lack of decision‐making power. Our findings indicate that addressing barriers to use and adoption of health IT may allow for expansion of these tools among cancer genetic counselors. Integrating health IT is critical for enhancing cancer genetic counselors’ capacity to address patient needs and realizing the potential of precision medicine.

Gastroenterology, May 1, 2019

Statistics in Medicine

When the number of baseline covariates whose imbalance needs to be controlled in a sequential ran... more When the number of baseline covariates whose imbalance needs to be controlled in a sequential randomized controlled trial is large, minimization is the most commonly used method for randomizing treatment assignments. The lack of allocation randomness associated with the minimization method has been the source of controversy, and the need to reduce even minor imbalances inherent in the minimization method has been challenged. The minimal sufficient balance (MSB) method is an alternative to the minimization method. It prevents serious imbalance from a large number of covariates while maintaining a high level of allocation randomness. In this study, the two treatment allocation methods are compared with regards to the effectiveness of balancing covariates across treatment arms and allocation randomness in equal allocation clinical trials. The MSB method proves to be equal or superior in both respects. In addition, type I error rate is preserved in analyses for both balancing methods, when using a binary endpoint.

Journal of Plastic, Reconstructive & Aesthetic Surgery

Digestive Diseases and Sciences

Background and Aims We hypothesized that mechanically ventilated cirrhotic patients not only have... more Background and Aims We hypothesized that mechanically ventilated cirrhotic patients not only have poor outcomes, but also that certain clinical variables are likely to be associated with mortality. We aimed to describe the predictors of mortality in these patients. Methods This observational study examined 113 mechanically ventilated cirrhotic patients cared for at our institution between July 1, 2014, and February 28, 2018. We performed bivariate and multivariate analyses to identify risk factors for mortality on mechanical ventilation and created an equation to calculate probability of mortality based on these variables. Results Seventy percent of patients had a history of a decompensating event. Altered mental status was the most frequently encountered indication for intubation (46%). 53% patients died on mechanical ventilation. After controlling for variables associated with increased mortality, multivariate analysis revealed that vasopressor use was the strongest predictor of mortality on mechanical ventilation (OR = 9.3) followed by sepsis (OR = 4.1). A formula with an area under the curve of 0.85 was obtained in order to predict the probability of mortality for cirrhotic patients on mechanical ventilation (available at https://medweb.musc.edu/mvcp/ ). This model (AUC = 0.85) outperformed the CLIF-SOFA score (AUC = 0.68) in predicting mortality in this cohort. Conclusion Cirrhotic patients requiring mechanical ventilation have an extremely poor prognosis, and in patients requiring vasopressors, having a history of decompensation, sepsis or low albumin, mortality is higher. Our data points to the clinical variables should be considered in the medical management of these patients and provide physicians with a formula to predict the probability of mortality.

Telemedicine and e-Health

BACKGROUND Clinical trials are key to ensuring high-quality, effective, and safe health care inte... more BACKGROUND Clinical trials are key to ensuring high-quality, effective, and safe health care interventions, but there are many barriers to their successful and timely implementation. Difficulties with participant recruitment and enrollment are largely affected by difficulties with obtaining informed consent. Teleconsent is a telemedicine- based approach to obtaining informed consent and offers a unique solution to limitations of traditional consent approaches. METHODS We conducted a survey among 134 clinical trial researchers in academic/university-, industry-, and clinically based settings. The survey addressed important aspects of teleconsent, potential teleconsent enhancements, and other telehealth capabilities to support clinical research. RESULTS The majority of respondents viewed teleconsent as an important approach for obtaining informed consent and indicated that they would likely use teleconsent if available. Consenting participants at remote sites, increasing access to clinical trials, and consenting participants in their homes were viewed as the greatest opportunities for teleconsent. Features for building, validating, and assessing understanding of teleconsent forms, mobile capabilities, three-way teleconsent calls, and direct links to forms via recruitment websites were viewed as important teleconsent enhancements. Other telehealth capabilities to support clinical research, including surveys, file transfer, three-way video, screenshare, and photo capture during telemedicine visits, and proposed telemedicine capabilities such as video call recording, ID information capture, and integration of medical devices, were also viewed as important. CONCLUSIONS Teleconsent and telemedicine are promising solutions to some common challenges to clinical trials. Many barriers to study recruitment and enrollment might be overcome by investing time and resources and further evaluating this technology.

The College Mathematics Journal

Douglas Lyman Corey (corey@mathed.byu.edu) earned a Ph.D. in Mathematics Education from the Unive... more Douglas Lyman Corey (corey@mathed.byu.edu) earned a Ph.D. in Mathematics Education from the University of Michigan in 2007. He holds two Master’s degrees, one in Mathematics and one in Statistics. His current work focuses on the ways that Japanese teachers teach and learn to teach. He enjoys teaching calculus and enjoys applying calculus to everyday situations. In his free time he plays with his eight kids, all of whom are girls but seven.

Molecular Genetics & Genomic Medicine