William A. Knaus

University of Virginia | UVa · Department of Public Health Sciences

Background: During the coronavirus disease-2019 (COVID-19) pandemic cumulative United States COVID-19 deaths per capita were higher than all other large, high-income nations, but with substantial variation across the country. Objective: The aim was to detail the public health response during the pandemic in Eagle County, Colorado. Research desi...

The objective of this study was to refine the APACHE (Acute Physiology, Age, Chronic Health Evaluation) methodology in order to more accurately predict hospital mortality risk for critically ill hospitalized adults. We prospectively collected data on 17,440 unselected adult medicall surgical intensive care unit (ICU) admissions at 40 US hospitals (...

Importance Critical care resources like ventilators, used to manage the current COVID-19 pandemic, are potentially inadequate. Established triage standards and guidelines may not contain the most appropriate severity assessment and outcome prediction models. Objectives Develop a draft pandemic specific triage assessment score for the current COVID-...

In this issue of JAMA, Seymour and his multidisciplinary team of coauthors¹ aim to improve the current understanding of sepsis by identifying new clinical phenotypes using machine learning clustering techniques. The authors assume that current sepsis definitions are too broad and clinically imprecise to untangle complex clinical and biological inte...

Background Accurate breast cancer risk assessment for women attending routine screening is needed to guide screening and preventive interventions. We evaluated the accuracy of risk predictions from both visual and volumetric mammographic density combined with the Tyrer-Cuzick breast cancer risk model. Methods A case-control study (474 patient part...

Purpose: Breast density reduces the sensitivity of mammography and is a moderate independent risk factor for breast cancer. Virginia is one of 24 states that currently require notification of patients when they have dense breasts. However, little is known about what women in the general population know about breast density. This survey study asses...

Personal and family health histories remain important independent risk factors for cancer; however they are currently not being well collected or used effectively. Health Heritage was designed to address this need. The purpose of this study was to validate the ability of Health Heritage to identify patients appropriate for further genetic evaluatio...

Background: Over the last several years there has been confusion among women about breast cancer screening and patient advocates are increasingly used to help women understand the changes. In 2009, the U.S. Preventive Task Force (USPSTF) recommended that women under the age of 50 do not need routine screening. New state laws require breast density...

Introduction: There is increasing interest in implementing personalized breast cancer screening strategies rather than relying on population based guidelines. Most risk models do not include breast density and two models that do rely on subjective BI-RADS categories; all have limited discriminatory ability (C-statistics ranging from 0.60-0.74). Our...

This purpose of this study is to evaluate the willingness of women to change their breast cancer screening practices if given personalized recommendations based on risk factors such as breast density, family history and lifestyle. A random sample of 1,024 Virginia women between age 35-70 years and without breast cancer, reached by landline and cell...

Breast density reduces the sensitivity of mammography and is a moderate independent breast cancer risk factor. Virginia is one of fourteen states that currently require providers to notify patients when they have dense breasts. However, little is known about what women in the general population know and understand about breast density. This surve...

277 Background: Family history is critical to assess risk for cancer and inherited cancer syndromes. National Comprehensive Cancer Network (NCCN) guidelines are available to aid in identification and management of at-risk patients, but the guidelines are complex and ever-changing, hindering optimal use. This leads to under-recognition and mismanage...

Genome-wide association studies, DNA sequencing studies, and other genomic studies are finding an increasing number of genetic variants associated with clinical phenotypes that may be useful in developing diagnostic, preventive, and treatment strategies for individual patients. However, few variants have been integrated into routine clinical practi...

A major promise of genomic research is information that can transform health care and public health through earlier diagnosis, more effective prevention and treatment of disease, and avoidance of drug side effects. Although there is interest in the early adoption of emerging genomic applications in cancer prevention and treatment, there are substan...

Introduction A decrease in disease-specific mortality over the last twenty years has been reported for patients admitted to United States (US) hospitals, but data for intensive care patients are lacking. The aim of this study was to describe changes in hospital mortality and case-mix using clinical data for patients admitted to multiple US ICUs ove...

The clinical utility is uncertain for many cancer genomic applications. Comparative effectiveness research (CER) can provide evidence to clarify this uncertainty. The aim of this study was to identify approaches to help stakeholders make evidence-based decisions and to describe potential challenges and opportunities in using CER to produce evidence...

A detailed family health history is currently the most potentially useful tool for diagnosis and risk assessment in clinical genetics. We developed and evaluated the usability and analytic validity of a patient-driven web-based family health history collection and analysis tool. Health Heritage(©) guides users through the collection of their family...

The U.S. urgently needs a major initiative to develop software and systems engineering foundations for a national-scale health information network (NHIN). The NHIN will be an ultra-large-scale (ULS) system. An ULS systems perspective therefore must guide these activities. There are enormous opportunities in this area for software engineering and co...

In this paper we propose a four-part random effects model, with application to correlated medical cost data. Four joint equations are used to model respectively: (1) the probability of seeking medical treatment, (2) the probability of being hospitalized (conditional on seeking medical treatment), and the actual amount of (3) outpatient and (4) inpa...

Receiving extraneous articles in response to a query submitted to MEDLINE/PubMed is common. When submitting a multi-word query (which is the majority of queries submitted), the presence of all query words within each article may be a necessary condition for retrieving relevant articles, but not sufficient. Ideally a relationship between the query w...

Clinical repositories containing large amounts of biological, clinical, and administrative data are increasingly becoming available as health care systems integrate patient information for research and utilization objectives. To investigate the potential value of searching these databases for novel insights, we applied a new data mining approach, H...

Data mining can be utilized to automate analysis of substantial amounts of data produced in many organizations. However, data mining produces large numbers of rules and patterns, many of which are not useful. Existing methods for pruning uninteresting patterns have only begun to automate the knowledge acquisition step (which is required for subject...

Purpose Treatment access underlies quality cancer care. We hypothesize that mastectomy rates in a rural state are independently influenced by distance to radiation therapy (XRT) and by changing XRT access through opening new facilities. Patients and Methods Early-stage breast cancer patients diagnosed from 1996 to 2000 were identified in the Virgin...

Treatment access underlies quality cancer care. We hypothesize that mastectomy rates in a rural state are independently influenced by distance to radiation therapy (XRT) and by changing XRT access through opening new facilities. Early-stage breast cancer patients diagnosed from 1996 to 2000 were identified in the Virginia state registry. Distance f...

To use an existing database from a large cohort study with follow-up as long as 5.5 years to assess the extended prognosis of patients who survived their hospitalizations for severe acute respiratory failure (ARF). Secondary analysis of an inception cohort of 1,722 patients with ARF requiring mechanical ventilation from five major medical centers w...

Despite the presence of tumor Ag-specific CD8(+) T cells in the peripheral blood, metastatic melanoma often evades immune-mediated destruction. Even after therapeutic efforts to expand Ag-specific T-cell populations, the correlation between magnitude of response and clinical efficacy has been weak. Because the migratory phenotype of tumor Ag-specif...

Developed by the Virginia Bioinformatics Consortium (VBC), GeneX Va is an open source, freeware database and bioinformatics analysis software for archiving and analyzing Affymetrix GeneChip data. It provides an integrated framework for management, documentation, and analysis of microarray experiments and data to support a range of users, from indiv...

As the Internet continues to grow as a delivery medium for health information, the design of effective Web sites becomes increasingly important. In this paper, the authors provide an overview of one effective model for Web site design, a user-centered process that includes techniques for needs assessment, goal/task analysis, user interface design,...

There is increasing interest in integrating population health and informatics topics into the undergraduate medical curriculum, yet little consensus exists on the most effective approach to accomplish this. We introduced the use of an academic data warehouse of encrypted patient information into an existing 2nd year medical school course. Exercises...

The development of APACHE (Acute Physiology and Chronic Health Evaluation) began on a Saturday in late June 1978 when I walked into the intensive care unit (ICU) of George Washington University Hospital in Washington, DC. I had come to Washington in 1972 and, with the exception of a year spent working in the former Soviet Union, had completed all o...

Well-established clinical risk factors in sepsis include adequacy of antibiotics, presence of underlying disease, source and type of infection, and the presence of shock with MOF. The heterogeneous nature of patients with sepsis and difficulty in reliably describing their disease burden has led to the development of illness severity scoring systems...

Process assessment has a short and not terribly impressive record within medical science. Nevertheless there are lessons to be learned from its history that could be useful for the future direction and emphasis of clinical and health services research within intensive care medicine. More importantly, recent evidence suggests that intensive care may...

Background To assess the performance of the prediction equation of the apache (acute physiology age and chronic health evaluation) iii prognostic scoring system when applied in spain. Patients and method Prospective multicenter cohort study that included 10786 adult patients from 86 Spanish intensive care units (icu). Data collection during first...

To assess the performance of the prediction equation of the APACHE(Acute Physiology Age and Chronic Health Evaluation) III prognostic scoring system when applied in Spain. Prospective multicenter cohort study that included 10786 adult patients from 86 Spanish intensive care units (ICU). Data collection during first 24 hours of admission: acute phys...

In order to develop the most effective health information web sites or instructional materials for physicians and consumers, designers frequently use a suite of best design practices, including Needs Assessment, Goal Analysis, User Interface Principles, and Rapid Prototyping. These best practices are not enough, however. If designers want to ensure...

The aim of the Resident Assessment Performance System (RAPS) project is to develop a web-based tool that would use routinely collected clinical data to evaluate a residents experience and performance. To ensure the tools usefulness and before any actual programming is done, it is essential to have an understanding of the stakeholders' needs and des...

To compare case-mix adjusted intensive care unit (ICU) length of stay for critically ill patients with a variety of medical and surgical diagnoses during a 5-yr interval. Nonrandomized cohort study. A total of 42 ICUs at 40 US hospitals during 1988-1990 and 285 ICUs at 161 US hospitals during 1993-1996. A total of 17,105 consecutive ICU admissions...

the FHx. METHODS We have developed a web-based application for collecting FHx directly from patients. 1 Underlying this application is a representation that uses detailed information about family members to build a family history profile for the participant. This representation uses a three-step process to collect and organize information. (Figure...

This study was undertaken to develop a comprehensive risk-assessment approach capable of evaluating maternal and fetal outcomes. Data from 10,984 women and 11,066 infants delivered at 79 military treatment facilities in the United States from 1995 to 1997 were used to develop two individual but complementary risk-adjustment models for maternal and,...

To develop and validate a model estimating the survival time of hospitalized persons aged 80 years and older. A prospective cohort study with mortality follow-up using the National Death Index. Four teaching hospitals in the US. Hospitalized patients enrolled between January 1993 and November 1994 in the Hospitalized Elderly Longitudinal Project (H...

To examine factors associated with family satisfaction with end-of-life care in the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT). A prospective cohort study with patients randomized to either usual care or an intervention that included clinical nurse specialists to assist in symptom control and facili...

We evaluated prospectively the use of acute hemodialysis among hospitalized patients to identify demographic and clinical predictors of and chart documentation concerning dialysis withheld and withdrawn. Prospective cohort study. Five teaching hospitals. Five hundred sixty-five seriously ill hospitalized patients who had not previously undergone di...

OBJECTIVE: To develop and validate a model estimating the survival time of hospitalized persons aged 80 years and older.DESIGN: A prospective cohort study with mortality follow-up using the National Death Index.SETTING: Four teaching hospitals in the US.PARTICIPANTS: Hospitalized patients enrolled between January 1993 and November 1994 in the Hospi...

The great variability of outcome seen in stroke patients has led to an interest in identifying predictors of outcome. The combination of clinical and imaging variables as predictors of stroke outcome in a multivariable risk adjustment model may be more powerful than either alone. The purpose of this study was to determine the multivariable relation...

Older age is associated with less aggressive treatment and higher short-term mortality due to serious illness. It is not known whether less aggressive care contributes to this survival disadvantage in elderly persons. To determine the effect of age on short-term survival, independent of baseline patient characteristics and aggressiveness of care. S...

To examine the degree to which variation in place of death is explained by differences in the characteristics of patients, including preferences for dying at home, and by differences in the characteristics of local health systems. We drew on a clinically rich database to carry out a prospective study using data from the observational phase of the S...

OBJECTIVE: To examine the degree to which variation in place of death is explained by differences in the characteristics of patients, including preferences for dying at home, and by differences in the characteristics of local health systems.DESIGN: We drew on a clinically rich database to carry out a prospective study using data from the observatio...

To assess the accuracy and validity of Acute Physiology and Chronic Health Evaluation (APACHE) III hospital mortality predictions in an independent sample of U.S. intensive care unit (ICU) admissions. Nonrandomized, observational, cohort study. Two hundred eighty-five ICUs in 161 U.S. hospitals, including 65 members of the Council of Teaching Hospi...

To customize the Acute Physiology and Chronic Health Evaluation (APACHE) III mortality equation for Spanish admissions to the intensive care unit (ICU) and evaluate its discrimination and calibration. Prospective multicenter inception cohort study. 86 ICUs located in all regions of Spain. 10,929 adult patients selected by a systematic sampling meth...

Congestive heart failure (CHF) is a common disease with high health care costs and high mortality rates. Knowledge of the health-related quality of life outcomes of CHF may guide decision making and be useful in assessing new therapies for this population. A prospective cohort study was conducted involving 1390 adult patients hospitalized with an a...

Background Congestive heart failure (CHF) is a common disease with high health care costs and high mortality rates. Knowledge of the health-related quality of life outcomes of CHF may guide decision making and be useful in assessing new therapies for this population.Methods A prospective cohort study was conducted involving 1390 adult patients ho...

The high cost and scarcity of intensive care unit (ICU) beds has resulted in a need for improved utilization. This study describes the characteristics of patients who are admitted to the ICU for neurosurgical and neurological care, identifies patients who might receive all or most of their care in an intermediate care unit, and describes the servic...

This study was performed to develop an intensive care unit (ICU) admission risk score based on preoperative condition and intraoperative events. This score provides a tool with which to judge the effects of ICU quality of care on outcome. Data were collected prospectively on 4,918 patients (study group n = 2,793 and a validation data set n = 2,125)...

To develop a predictive equation to estimate the frequency of blood drawing for intensive care unit (ICU) laboratory tests and to evaluate variations in ICU blood sampling practices after adjusting for patient and institutional factors. Prospective, inception, cohort study. Forty-two ICUs in 40 hospitals, including 20 teaching and 17 nonteaching IC...

Objective: To assess the effectiveness of written advance directives (ADs) in the care of seriously ill, hospitalized patients. In particular, to conduct an assessment after ADs were promoted by the Patient Self-Determination Act (PSDA) and enhanced by the effort to improve decision-making in the Study to Understand Prognoses and Preferences for O...

To evaluate whether the lack of effect of advance directives (ADs) on decision-making in SUPPORT might arise, in part, from the content of the actual documents. Advance directives placed in the medical records were abstracted for date of completion and content of additional written instructions. We examined directives with instructions to forgo lif...

Would increasing the documentation of advance directives (ADs) lead to a reduction in resource utilization? We examined this question by conducting three secondary analyses: (1) we tested for a change in resource use among those who died in the hospital at a time before and after an intervention that increased the documentation of ADs in the medica...

Objectives: To develop a predictive equation to estimate the frequency of blood drawing for intensive care unit (ICU) laboratory tests and to evaluate variations in ICU blood sampling practices after adjusting for patient and institutional factors. Design: Prospective, inception, cohort study. Setting: Forty-two ICUs in 40 hospitals, including 20 t...

OBJECTIVE: To evaluate whether the lack of effect of advance directives (ADs) on decision-making in SUPPORT might arise, in part, from the content of the actual documents.DESIGN: Advance directives placed in the medical records were abstracted for date of completion and content of additional written instructions. We examined directives with instruc...

Objective: Would increasing the documentation of advance directives (ADs) lead to a reduction in resource utilization? We examined this question by conducting three secondary analyses: (1) we tested for a change in resource use among those who died in the hospital at a time before and after an intervention that increased the documentation of ADs i...

To test the effect of a novel bradykinin antagonist, deltibant (CP-0127), on survival, organ dysfunction, and other outcomes in patients with the systemic inflammatory response syndrome (SIRS) and presumed sepsis. Multicenter, randomized, placebo-controlled, double-blind, parallel, dose-ranging trial. Follow-up for 28 days or until death. A total o...

Objective. —To test the effect of a novel bradykinin antagonist, deltibant (CP-0127), on survival, organ dysfunction, and other outcomes in patients with the systemic inflammatory response syndrome (SIRS) and presumed sepsis.

In Reply. —In our prospective observational cohort study of RHC, we adjusted for treatment selection bias using a multivariable propensity score. The adjustment was done using 2 standard techniques: multivariable analysis in all 5735 patients, which should yield the best estimate of the treatment effect, and matched-pair analysis in 2016 patients,...

APACHE is a useful tool for improving intensive care and meeting the new demands created by health care reforms. As part of an integrated quality improvement plan, APACHE III can provide information that will lead to improvements in patient triage, resource use and overall ICU effectiveness. Critical care physicians need to familiarise themselves w...

To describe the variation in frequency of do-not-resuscitate (DNR) orders in 42 US ICUs and to examine the relationship between published guidelines and qualitative observations about terminal care in 9 ICUs. Prospective inception cohort. Forty-two ICUs in 40 US hospitals with more than 200 beds: 26 randomly selected and 14 large tertiary-care volu...

In order to describe the outcomes of patients hospitalized with an acute exacerbation of severe chronic obstructive pulmonary disease (COPD) and determine the relationship between patient characteristics and length of survival, we studied a prospective cohort of 1,016 adult patients from five hospitals who were admitted with an exacerbation of COPD...