471 research outputs found
The Stanford Health Assessment Questionnaire: Dimensions and Practical Applications
The ability to effectively measure health-related quality-of-life longitudinally is central to describing the impacts of disease, treatment, or other insults, including normal aging, upon the patient. Over the last two decades, assessment of patient health status has undergone a dramatic paradigm shift, evolving from a predominant reliance on biochemical and physical measurements, such as erythrocyte sedimentation rate, lipid profiles, or radiographs, to an emphasis upon health outcomes based on the patient's personal appreciation of their illness. The Health Assessment Questionnaire (HAQ), published in 1980, was among the first instruments based on generic, patient-centered dimensions. The HAQ was designed to represent a model of patient-oriented outcome assessment and has played a major role in many diverse areas such as prediction of successful aging, inversion of the therapeutic pyramid in rheumatoid arthritis (RA), quantification of NSAID gastropathy, development of risk factor models for osteoarthrosis, and examination of mortality risks in RA. Evidenced by its use over the past two decades in diverse settings, the HAQ has established itself as a valuable, effective, and sensitive tool for measurement of health status. It is available in more than 60 languages and is supported by a bibliography of more than 500 references. It has increased the credibility and use of validated self-report measurement techniques as a quantifiable set of hard data endpoints and has contributed to a new appreciation of outcome assessment. In this article, information regarding the HAQ's development, content, dissemination and reference sources for its uses, translations, and validations are provided
A Study of the Dynamics of Cardiac Ischemia using Experimental and Modeling Approaches
The dynamics of cardiac ischemia was investigated using experimental studies and computer simulations. An experimental model consisting of an isolated and perfused canine heart with full control over blood flow rate to a targeted coronary artery was used in the experimental study and a realistically shaped computer model of a canine heart, incorporating anisotropic conductivity and realistic fiber orientation, was used in the simulation study. The phenomena investigated were: (1) the influence of fiber rotation on the epicardial potentials during ischemia and (2) the effect of conductivity changes during a period of sustained ischemia. Comparison of preliminary experimental and computer simulation results suggest that as the ischemic region grows from the endocardium towards the epicardium, the epicardial potential patterns follow the rotating fiber orientation in the myocardium. Secondly, in the experimental studies it was observed that prolonged ischemia caused a subsequent reduction in the magnitude of epicardial potentials. Similar results were obtained from the computer model when the conductivity of the tissue in the ischemic region was reduce
Compression of Morbidity 1980–2011: A Focused Review of Paradigms and Progress
The Compression of Morbidity hypothesis—positing that the age of onset of chronic illness may be postponed more than the age at death and squeezing most of the morbidity in life into a shorter period with less lifetime disability—was introduced by our group in 1980. This paper is focused upon the evolution of the concept, the controversies and responses, the supportive multidisciplinary science, and the evolving lines of evidence that establish proof of concept. We summarize data from 20-year prospective longitudinal studies of lifestyle progression of disability, national population studies of trends in disability, and randomized controlled trials of risk factor reduction with life-style-based “healthy aging” interventions. From the perspective of this influential and broadly cited paradigm, we review its current history, the development of a theoretical structure for healthy aging, and the challenges to develop coherent health policies directed at reduction in morbidity
Exploring the Area of Rectangles and their Applications
We will explain how to find the area of rectangles using the TI 84 tutorial. We will use “Area Explorer” from Project Interactivate to demonstrate how to find the area of different rectangular shapes. A Pre-designed house plan from GSP will be given to the students (to be loaded in each computer) to simulate a floor renewal. Students will calculate different areas from the house floor plan and collect the data
Cytokines in Pigs Bred Selectively for High and Low Immune Response [abstract only]
Yorkshire pigs have been bred for high (H) and low (L) immune response based on selection for multiple antibody (Ab) and cell mediated immune response traits. High responders have better production and larger litter size when compared with controls and low responders. The ability of high and low line pigs to resist M. hyorhinis infection has been tested. The high responders had more rapid and higher Ab response and the severity of the disease was less, as judged by clinical and postmortem signs. However, arthritis was found to be relatively more severe in high responders. We hypothesized that the immune response differences between genetically different lines could be attributed to either dominant or differential cytokine expression.
To test the above hypothesis, quantitative RNA PCR (Q.RNA PCR), to quantitate the porcine cytokines at the mRNA level, was developed by constructing an internal control. Two synthetic oligos, namely 5\u27 construct (FPC) and 3\u27 construct (TPC), were designed based on the nt sequences of porcine cytokine genes. FPC represented the upstream primer sequences of nine cytokines sequentially in the order IL-1, IL-4, IL-6, IL-8, IL-2, IL-1O, TNF-α, TNF-β and IFN-γ, and TPC, the downstream primer sequences in the same order. The primers were designed such that when cRNA and target RNA were amplified, they give two non-overlapping products. FPCs and TPCs were constructed by overlapping and the extension method of PCR amplification utilizing six oligos for each, and were cloned into pSP 64 poly A vector. The application of Q.RNA PCR has been tested for determining quantitatively the cytokines in peripheral blood mononuclear cells in H-L line pigs. Preliminary study indicated differential expression of cytokines, namely IL-1, IL-6, IL-1O, TNF-α and IFN-γ, in naive animals. Expression of other cytokines, namely IL-2, IL-4, IL-8 and TNF-β, was absent in the pigs tested. Future studies involve the determination of cytokines in the context of immunization to the antigens (HEWL, BCG, etc.) as well as during infection (ex: M. hyorhinis) in conjunction with cytokine expression regulation strategies, namely MAbs and/or antisense ODNs or gene therapy
Improved responsiveness and reduced sample size requirements of PROMIS physical function scales with item response theory
INTRODUCTION: The Health Assessment Questionnaire Disability Index (HAQ) and the SF-36 PF-10, among other instruments, yield sensitive and valid Disability (Physical Function) endpoints. Modern techniques, such as Item Response Theory (IRT), now enable development of more precise instruments using improved items. The NIH Patient Reported Outcomes Measurement Information System (PROMIS) is charged with developing improved IRT-based tools. We compared the ability to detect change in physical function using original (Legacy) instruments with Item-Improved and PROMIS IRT-based instruments.
METHODS: We studied two Legacy (original) Physical Function/Disability instruments (HAQ, PF-10), their item-improved derivatives (Item-Improved HAQ and PF-10), and the IRT-based PROMIS Physical Function 10- (PROMIS PF 10) and 20-item (PROMIS PF 20) instruments. We compared sensitivity to detect 12-month changes in physical function in 451 rheumatoid arthritis (RA) patients and assessed relative responsiveness using P-values, effect sizes (ES), and sample size requirements.
RESULTS: The study sample was 81% female, 87% Caucasian, 65 years of age, had 14 years of education, and had moderate baseline disability. All instruments were sensitive to detecting change (\u3c 0.05) in physical function over one year. The most responsive instruments in these patients were the Item-Improved HAQ and the PROMIS PF 20. IRT-improved instruments could detect a 1.2% difference with 80% power, while reference instruments could detect only a 2.3% difference (P \u3c 0.01). The best IRT-based instruments required only one-quarter of the sample sizes of the Legacy (PF-10) comparator (95 versus 427). The HAQ outperformed the PF-10 in more impaired populations; the reverse was true in more normal populations. Considering especially the range of severity measured, the PROMIS PF 20 appears the most responsive instrument.
CONCLUSIONS: Physical Function scales using item improved or IRT-based items can result in greater responsiveness and precision across a broader range of physical function. This can reduce sample size requirements and thus study costs
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