Stephen L Hillis

Summary

Affiliation: University of Iowa
Country: USA

Publications

  1. ncbi request reprint A comparison of the Dorfman-Berbaum-Metz and Obuchowski-Rockette methods for receiver operating characteristic (ROC) data
    Stephen L Hillis
    Center for Research in the Implementation of Innovative Strategies in Practice, Iowa City VA Medical Center, Iowa City, IA, USA
    Stat Med 24:1579-607. 2005
  2. pmc A comparison of denominator degrees of freedom methods for multiple observer ROC analysis
    Stephen L Hillis
    Center for Research in the Implementation of Innovative Strategies in Practice, Iowa City VA Medical Center, Iowa City, IA 52246 2208, USA
    Stat Med 26:596-619. 2007
  3. pmc Power estimation for multireader ROC methods an updated and unified approach
    Stephen L Hillis
    Iowa City VA Medical Center, IA 52246 2208, USA
    Acad Radiol 18:129-42. 2011
  4. pmc An analytic expression for the binormal partial area under the ROC curve
    Stephen L Hillis
    Departments of Radiology and Biostatistics, University of Iowa, 3170 Medical Laboratories, 200 Hawkins Drive, Iowa City, IA 52242 1077, USA
    Acad Radiol 19:1491-8. 2012
  5. pmc Simulation of unequal-variance binormal multireader ROC decision data: an extension of the Roe and Metz simulation model
    Stephen L Hillis
    Departments of Radiology and Biostatistics, University of Iowa, 3170 Medical Laboratories, 200 Hawkins Drive, Iowa City, IA 52242 1077, USA
    Acad Radiol 19:1518-28. 2012
  6. pmc Monte Carlo validation of the Dorfman-Berbaum-Metz method using normalized pseudovalues and less data-based model simplification
    Stephen L Hillis
    Center for Research in the Implementation of Innovative Strategies in Practice CRIISP, Iowa City VA Medical Center 152, 601 Highway 6 West, Iowa City, IA 52246 2208, USA
    Acad Radiol 12:1534-41. 2005
  7. pmc Using the mean-to-sigma ratio as a measure of the improperness of binormal ROC curves
    Stephen L Hillis
    Department of Veterans Affairs Iowa City Medical Center, IA 52246 2208, USA
    Acad Radiol 18:143-54. 2011
  8. pmc Recent developments in the Dorfman-Berbaum-Metz procedure for multireader ROC study analysis
    Stephen L Hillis
    Center for Research in the Implementation of Innovative Strategies in Practice CRIISP, Iowa City VA Medical Center 152, Iowa City, IA, USA
    Acad Radiol 15:647-61. 2008
  9. ncbi request reprint Power estimation for the Dorfman-Berbaum-Metz method
    Stephen L Hillis
    Center for Research in the Implementation of Innovative Strategies in Practice CRIISP, Iowa City VA Medical Center, Iowa, USA
    Acad Radiol 11:1260-73. 2004
  10. doi request reprint Impact of functional limitations and medical comorbidity on subsequent weight changes and increased depressive symptoms in older adults
    Valerie L Forman-Hoffman
    Department of Internal Medicine, Iowa City Veterans Affairs Medical Center, University of Iowa College of Medicine, SE 605 GH, 200 Hawkins Drive, Iowa City, IA 52242, USA
    J Aging Health 20:367-84. 2008

Detail Information

Publications45

  1. ncbi request reprint A comparison of the Dorfman-Berbaum-Metz and Obuchowski-Rockette methods for receiver operating characteristic (ROC) data
    Stephen L Hillis
    Center for Research in the Implementation of Innovative Strategies in Practice, Iowa City VA Medical Center, Iowa City, IA, USA
    Stat Med 24:1579-607. 2005
    ..The methods are compared using data from a factorial study with two modalities, five readers, and 114 patients...
  2. pmc A comparison of denominator degrees of freedom methods for multiple observer ROC analysis
    Stephen L Hillis
    Center for Research in the Implementation of Innovative Strategies in Practice, Iowa City VA Medical Center, Iowa City, IA 52246 2208, USA
    Stat Med 26:596-619. 2007
    ..I propose a new ddf method that overcomes both of these problems and can be used with either the OR or DBM procedure...
  3. pmc Power estimation for multireader ROC methods an updated and unified approach
    Stephen L Hillis
    Iowa City VA Medical Center, IA 52246 2208, USA
    Acad Radiol 18:129-42. 2011
    ..This procedure updates previous approaches by incorporating recent methodological developments and unifies the approaches by allowing inputs to be conjectured parameter values or outputs from either a DBM or OR pilot-study analysis...
  4. pmc An analytic expression for the binormal partial area under the ROC curve
    Stephen L Hillis
    Departments of Radiology and Biostatistics, University of Iowa, 3170 Medical Laboratories, 200 Hawkins Drive, Iowa City, IA 52242 1077, USA
    Acad Radiol 19:1491-8. 2012
    ..Instead, the pAUC has been computed using numerical integration or a rational polynomial approximation. Our purpose is to provide analytic expressions for the two forms of pAUC...
  5. pmc Simulation of unequal-variance binormal multireader ROC decision data: an extension of the Roe and Metz simulation model
    Stephen L Hillis
    Departments of Radiology and Biostatistics, University of Iowa, 3170 Medical Laboratories, 200 Hawkins Drive, Iowa City, IA 52242 1077, USA
    Acad Radiol 19:1518-28. 2012
    ..This article extends the RM model by allowing the diseased and nondiseased decision-variable distributions to have unequal variances for each reader...
  6. pmc Monte Carlo validation of the Dorfman-Berbaum-Metz method using normalized pseudovalues and less data-based model simplification
    Stephen L Hillis
    Center for Research in the Implementation of Innovative Strategies in Practice CRIISP, Iowa City VA Medical Center 152, 601 Highway 6 West, Iowa City, IA 52246 2208, USA
    Acad Radiol 12:1534-41. 2005
    ..Our purpose is to empirically investigate if these two modifications--normalized pseudovalues and less data-based model simplification--result in improved performance...
  7. pmc Using the mean-to-sigma ratio as a measure of the improperness of binormal ROC curves
    Stephen L Hillis
    Department of Veterans Affairs Iowa City Medical Center, IA 52246 2208, USA
    Acad Radiol 18:143-54. 2011
    ..Presently, standard statistical software does not provide diagnostics for assessing the magnitude of the improperness...
  8. pmc Recent developments in the Dorfman-Berbaum-Metz procedure for multireader ROC study analysis
    Stephen L Hillis
    Center for Research in the Implementation of Innovative Strategies in Practice CRIISP, Iowa City VA Medical Center 152, Iowa City, IA, USA
    Acad Radiol 15:647-61. 2008
    ..Recently, solutions to these problems have been presented in three papers. Our purpose is to summarize and provide an overview of these recent developments...
  9. ncbi request reprint Power estimation for the Dorfman-Berbaum-Metz method
    Stephen L Hillis
    Center for Research in the Implementation of Innovative Strategies in Practice CRIISP, Iowa City VA Medical Center, Iowa, USA
    Acad Radiol 11:1260-73. 2004
    ....
  10. doi request reprint Impact of functional limitations and medical comorbidity on subsequent weight changes and increased depressive symptoms in older adults
    Valerie L Forman-Hoffman
    Department of Internal Medicine, Iowa City Veterans Affairs Medical Center, University of Iowa College of Medicine, SE 605 GH, 200 Hawkins Drive, Iowa City, IA 52242, USA
    J Aging Health 20:367-84. 2008
    ..The primary goal of this study was to determine the effect of the onset of major medical comorbidity and functional decline on subsequent weight change and increased depressive symptoms...
  11. pmc Instability dependency of osteoarthritis development in a rabbit model of graded anterior cruciate ligament transection
    Yuki Tochigi
    Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa 52242, USA
    J Bone Joint Surg Am 93:640-7. 2011
    ..In a survival rabbit knee model of graded joint instability, the relationship between the magnitude of instability and the intensity of cartilage degeneration was studied at the organ level in vivo...
  12. pmc Changes in diet behavior when adults become parents
    Helena H Laroche
    Department of Internal Medicine, University of Iowa, and Iowa City Veterans Administration Medical Center, Iowa City, IA 52246, USA
    J Acad Nutr Diet 112:832-9. 2012
    ..Cross-sectional studies suggest that parents eat more saturated fat than nonparents. Few studies exist on other dietary factors or using longitudinal data...
  13. ncbi request reprint Retirement and weight changes among men and women in the health and retirement study
    Valerie L Forman-Hoffman
    Department of Internal Medicine, University of Iowa College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242, USA
    J Gerontol B Psychol Sci Soc Sci 63:S146-53. 2008
    ..The purpose of this study was to determine whether retirement was associated with either weight gain or weight loss...
  14. pmc Implementing smoking cessation guidelines for hospitalized veterans: effects on nurse attitudes and performance
    David A Katz
    Comprehensive Access and Delivery Research and Evaluation CADRE Center, VA Iowa City Health Care System 152, Iowa City, IA, 52246 2208, USA
    J Gen Intern Med 28:1420-9. 2013
    ..This study aims to determine the impact of a guideline-based intervention on 1) nurses' delivery of the 5A's (Ask-Advise-Assess-Assist-Arrange follow-up) in hospitalized smokers, and 2) nurses' attitudes toward the intervention...
  15. pmc Motion versus fixed distraction of the joint in the treatment of ankle osteoarthritis: a prospective randomized controlled trial
    Charles L Saltzman
    University of Iowa Hospital and Clinics, Iowa City, Iowa, USA
    J Bone Joint Surg Am 94:961-70. 2012
    ..We hypothesized that allowing ankle motion during distraction would result in significant improvements in outcomes compared with distraction without ankle motion...
  16. doi request reprint Effectiveness of home telehealth in comorbid diabetes and hypertension: a randomized, controlled trial
    Bonnie J Wakefield
    Department of Veterans Affairs Health Services Research and Development Center for Comprehensive Access and Delivery Research and Evaluation CADRE, Iowa City, Iowa 52246, USA
    Telemed J E Health 17:254-61. 2011
    ..Increased emphasis is being placed on the critical need to control hypertension (HTN) in patients with diabetes...
  17. pmc A prospective study of the PUSH tool in diabetic foot ulcers
    Sue E Gardner
    The University of Iowa, College of Nursing, Iowa City, IA, USA
    J Wound Ostomy Continence Nurs 38:385-93. 2011
    ..The purpose of this study was to examine the predictive validity of Pressure Ulcer Scale for Healing (PUSH; v. 3.0) in monitoring healing of neuropathic foot ulcers in patients with diabetes mellitus...
  18. ncbi request reprint Overactive bladder and mental health symptoms in recently deployed female veterans
    Catherine S Bradley
    Comprehensive Access and Delivery Research and Evaluation CADRE Center, Iowa City VA Health Care System, Iowa City, Iowa Departments of Obstetrics and Gynecology and Urology, University of Iowa Carver College of Medicine, Iowa City, Iowa Department of Epidemiology, University of Iowa College of Public Health, Iowa City, Iowa Electronic address
    J Urol 191:1327-32. 2014
    ....
  19. pmc The neuropathic diabetic foot ulcer microbiome is associated with clinical factors
    Sue E Gardner
    University of Iowa, College of Nursing, Iowa City, Iowa, USA
    Diabetes 62:923-30. 2013
    ..Analyses of microbial community membership and structure may provide the most useful metrics in prospective studies to delineate problematic bioburden from benign colonization that can then be used to drive clinical treatment...
  20. pmc Distribution and progression of chondrocyte damage in a whole-organ model of human ankle intra-articular fracture
    Yuki Tochigi
    Department of Orthopaedics and Rehabilitation, The University of Iowa, Iowa City, 52242, USA
    J Bone Joint Surg Am 93:533-9. 2011
    ..In this study, the distribution and progression of fracture-associated cell-level cartilage damage were assessed using a novel whole-organ model of human ankle intra-articular fracture...
  21. pmc Objective CT-based metrics of articular fracture severity to assess risk for posttraumatic osteoarthritis
    Thaddeus P Thomas
    Department of Orthopaedics and Rehabilitation, The University of Iowa, Iowa City, IA, USA
    J Orthop Trauma 24:764-9. 2010
    ..It was hypothesized that an injury severity metric that included objective measures of articular disruption, of fracture energy, and of fragment displacement/dispersal would be a useful predictor of PTOA...
  22. pmc Patient and physician beliefs about control over health: association of symmetrical beliefs with medication regimen adherence
    Alan J Christensen
    Department of Psychology, The University of Iowa, 11 Seashore Hall East, Iowa City, IA 52242, USA
    J Gen Intern Med 25:397-402. 2010
    ..Past work suggests that the degree of similarity between patient and physician attitudes may be an important predictor of patient-centered outcomes...
  23. pmc Clinical signs of infection in diabetic foot ulcers with high microbial load
    Sue E Gardner
    Center for Research in the Implementation of Innovative Strategies in Practice, Iowa City VA Medical Center, Iowa City Iowa, USA
    Biol Res Nurs 11:119-28. 2009
    ....
  24. doi request reprint Satisfaction and emergency department revisits in patients with possible acute coronary syndrome
    David A Katz
    Division of General Internal Medicine, University of Iowa Carver, College of Medicine, Iowa City, Iowa Center for Comprehensive Access and Delivery Research and Evaluation, Iowa City VA Medical Center, Iowa City, Iowa
    J Emerg Med 45:947-57. 2013
    ..Little is known about the relationship between patient satisfaction in the ED and subsequent return visits...
  25. ncbi request reprint Gleason score and laterality concordance between prostate biopsy and prostatectomy specimens
    Kenneth G Nepple
    Department of Urology, University of Iowa, Iowa City, Iowa 52242 1089, USA
    Int Braz J Urol 35:559-64. 2009
    ..We evaluated concordance in Gleason score and laterality between biopsy and radical retropubic prostatectomy (RRP) specimens and factors that influenced this relationship...
  26. ncbi request reprint Effects of weekend admission and hospital teaching status on in-hospital mortality
    Peter Cram
    Division of General Internal Medicine, Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242, USA
    Am J Med 117:151-7. 2004
    ..We compared mortality rates between patients admitted on weekends and weekdays and whether weekend-weekday variation in rates differed between patients admitted to teaching and nonteaching hospitals in California...
  27. ncbi request reprint The role of the interosseous talocalcaneal ligament in subtalar joint stability
    Yuki Tochigi
    Department of Orthopaedics and Rehabilitation, University of Iowa, USA
    Foot Ankle Int 25:588-96. 2004
    ..Clinical effects of ITCL failure remain unclear because of insufficient understanding of the role of the ligament...
  28. ncbi request reprint 4.5-gram monofilament sensation beneath both first metatarsal heads indicates protective foot sensation in diabetic patients
    Charles L Saltzman
    Department of Orthopaedic Surgery, University of Iowa, UIHC, 200 Hawkins Drive, Iowa City, IA 52246, USA
    J Bone Joint Surg Am 86:717-23. 2004
    ..The objective of the present study was to determine whether testing of fewer than ten sites could provide accuracy comparable with that obtained by testing all ten sites...
  29. pmc An empirically derived taxonomy of factors affecting physicians' willingness to disclose medical errors
    Lauris C Kaldjian
    Division of General Internal Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
    J Gen Intern Med 21:942-8. 2006
    ..However, the variables that may facilitate or impede disclosure are diverse and lack conceptual organization...
  30. doi request reprint The emergency department action in smoking cessation (EDASC) trial: impact on cessation outcomes
    David A Katz
    Department of Medicine, University of Iowa, Iowa City, IA, USA
    Nicotine Tob Res 15:1032-43. 2013
    ..The purpose of this study was to determine whether an emergency nurse- initiated intervention based on the 5A's (Ask-Advise-Assess-Assist-Arrange) framework improves quit rates...
  31. pmc The Emergency Department Action in Smoking Cessation (EDASC) trial: impact on delivery of smoking cessation counseling
    David A Katz
    Department of Medicine, University of Iowa, Iowa City, USA
    Acad Emerg Med 19:409-20. 2012
    ....
  32. doi request reprint Health beliefs toward cardiovascular risk reduction in patients admitted to chest pain observation units
    David A Katz
    Departments of Medicine and Emergency Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA
    Acad Emerg Med 16:379-87. 2009
    ..The aim of this study was to evaluate the premise that evaluation in an observation unit for symptoms of possible ACS is a "teachable moment" with regard to modification of CRFs...
  33. pmc Organ-level histological and biomechanical responses from localized osteoarticular injury in the rabbit knee
    Tanawat Vaseenon
    Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa, USA
    J Orthop Res 29:340-6. 2011
    ..Immediate injury-associated alterations in the medial compartment contact mechanics were also demonstrated. Localized osteoarticular injury in this survival animal model resulted in global joint histological changes...
  34. pmc Health perceptions in patients who undergo screening and workup for prostate cancer
    David A Katz
    Department of Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
    Urology 69:215-20. 2007
    ..This study was designed to determine whether a positive screening test with negative biopsy findings for prostate cancer is associated with worsened mental health during short-term follow-up...
  35. doi request reprint Prevalence of delayed clinician response to elevated prostate-specific antigen values
    Kenneth G Nepple
    Department of Urology, University of Iowa, Iowa City, IA, USA
    Mayo Clin Proc 83:439-45. 2008
    ..To assess the frequency of delayed response to an abnormal prostate-specific antigen (PSA) value...
  36. ncbi request reprint Primary tooth fluorosis and fluoride intake during the first year of life
    Steven M Levy
    Department of Preventive and Community Dentistry, University of Iowa College of Dentistry, Iowa City, IA 52242, USA
    Community Dent Oral Epidemiol 30:286-95. 2002
    ..The purpose of this paper is to report on analyses relating estimated prenatal fluoride intake and fluoride intake during different parts of the first year of life to primary tooth fluorosis...
  37. ncbi request reprint Do emergency department patients with possible acute coronary syndrome have better outcomes when admitted to cardiology versus other services?
    David A Katz
    Department of Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA
    Ann Emerg Med 51:561-70, 570.e1. 2008
    ....
  38. pmc Automated objective scoring of histologically apparent cartilage degeneration using a custom image analysis program
    S Farshid Moussavi-Harami
    Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa 52242 1100, USA
    J Orthop Res 27:522-8. 2009
    ..While limitations exist with image processing techniques, the new algorithm provides an objective and automated method for analyzing cartilage histology sections, consistent with human observer grading...
  39. ncbi request reprint Patient and physician attitudes in the health care context: attitudinal symmetry predicts patient satisfaction and adherence
    Jamie A Cvengros
    Department of Psychology, University of Iowa, Iowa City, IA 52242, USA
    Ann Behav Med 33:262-8. 2007
    ..There is increasing interest in the role that patient and physician health-related attitudes may play in predicting patient outcomes...
  40. ncbi request reprint Weight and depressive symptoms in older adults: direction of influence?
    Valerie L Forman-Hoffman
    Center for Research in the Implementation of Innovative Stategies in Practice, Iowa City Veteran s Affairs Medical Center, Iowa, USA
    J Gerontol B Psychol Sci Soc Sci 62:S43-51. 2007
    ..We used separate cross-lagged models for men and women in order to study the impact of weight change on subsequent increases in depressive symptoms 2 years later and vice versa...
  41. ncbi request reprint Diagnostic validity of three swab techniques for identifying chronic wound infection
    Sue E Gardner
    Center for Research in the Implementation of Innovative Strategies in Practice CRIISP, Iowa City VA Medical Center, IA, USA
    Wound Repair Regen 14:548-57. 2006
    ..The diagnostic validity of Levine's technique needs further study using an alternative reference standard, such as the development of infection-related complications...
  42. ncbi request reprint Prevalence and correlates of illness worry in the general population
    Russell Noyes
    Department of Psychiatry, University of Iowa, Roy J and Lucille A Carver College of Medicine, Iowa City, IA 52242 1000, USA
    Psychosomatics 46:529-39. 2005
    ..Worry about serious illness was associated with functional impairment and health care utilization...
  43. ncbi request reprint Multireader, multicase receiver operating characteristic analysis: an empirical comparison of five methods
    Nancy A Obuchowski
    Departments of Biostatistics and Epidemiology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
    Acad Radiol 11:980-95. 2004
    ..The objective of this article is to increase awareness of these methods and determine if their results are concordant for published datasets...
  44. ncbi request reprint Hepatitis C virus-infected patients report communication problems with physicians
    Susan Zickmund
    Department of Medicine, University of Pittsburgh College of Medicine, Pittsburgh, PA, USA
    Hepatology 39:999-1007. 2004
    ..These should target both specialists and primary care providers to inform them about the psychosocial challenges facing these patients...
  45. ncbi request reprint Laser fluorescence detection of occlusal caries
    Matthew B Tonioli
    College of Dentistry, The University of Iowa, Iowa City 52242 1001, USA
    Am J Dent 15:268-73. 2002
    ..This study compared six diagnostic methods with a histologic standard, including diode laser fluorescence, caries detection dye, and an operating microscope...