By V. Kliff. University of Wisconsin-Parkside. 2019.
Hepatitis and Liver Cancer: A National Strategy for Prevention and Control of Hepatitis B and C http://www 20mg vardenafil mastercard. Epidemic hepatitis C virus infection in Egypt: Es- timates of past incidence and future morbidity and mortality buy vardenafil paypal. Why we should routinely screen Asian Ameri- can adults for hepatitis B: A cross-sectional study of Asians in California order vardenafil 10mg. Incidence and risk factors for hepatitis C seroconversion in injecting drug users in Australia. Peginterferon alfa-2b and ribavirin for the treatment of chronic hepatitis C in blacks and non-Hispanic whites. The contribu- tions of hepatitis B virus and hepatitis C virus infections to cirrhosis and primary liver cancer worldwide. Hepatitis and Liver Cancer: A National Strategy for Prevention and Control of Hepatitis B and C http://www. Peginterferon alfa-2a and ribavirin in Latino and non-Latino whites with hepatitis C. Assessment of hepatitis C infection in injecting drug users attending an addiction treatment clinic. The natural history of hepatitis C virus infection: Host, viral, and environmental factors. Risk of hepatitis C virus infection among young adult injection drug users who share injection equipment. Table : Persons obtaining legal permanent resident status by region and country of birth: Fis- cal years to 00. Hepatitis and Liver Cancer: A National Strategy for Prevention and Control of Hepatitis B and C http://www. Prevention and control of infections with hepatitis viruses in correctional settings. Recommendations for identifcation and public health manage- ment of persons with chronic hepatitis B virus infection. Introduction of hepatitis B vaccine into childhood immunization services: Management guidelines, including information for health workers and parents. Estimating future hepatitis C morbidity, mortality, and costs in the United States. Epidemiology of hepatitis C virus infection among injection drug users in China: Systematic review and meta-analysis. Hepatitis and Liver Cancer: A National Strategy for Prevention and Control of Hepatitis B and C http://www. Surveillance data are used to estimate the magnitude of a health problem, to describe the natural history of a disease, to detect epidemics, to document the distribution and spread of a health event or disease, to evaluate control and prevention measures, and to aid in public-health planning (Thacker, 2000). Public-health surveillance requires standardized, systematic, continuing collection and management of data. Through those steps, federal agencies and state and local health depart- ments are able to inform stakeholders by providing reliable information that can be used to reduce morbidity and mortality through public policy, appropriate resource distribution, and programmatic and educational inter- ventions. This chapter describes how surveillance data are used or could be used to determine the focus and scope of viral hepatitis prevention and control efforts. The committee reviewed the weaknesses of the current surveillance system for hepatitis B and hepatitis C, including the timeliness, accuracy, and completeness of data collection, analysis, and dissemination. It found that there were few published sources of information about viral hepatitis surveillance. To obtain a clearer picture of the activities that were taking place at state and local levels, the committee gathered information from Copyright © National Academy of Sciences. Hepatitis and Liver Cancer: A National Strategy for Prevention and Control of Hepatitis B and C http://www. Identify chronic cases of hepatitis B and C and measure prevalence • Develop accurate estimates of the burden of chronic disease in United States • Prevent secondary cases o Hepatitis B: Education, vaccination, and screening o Hepatitis C: Education, harm reduction, and screening 3. Its fndings are based on its review of the literature and on information gathered through surveys of and direct contact with profes- sionals working in this feld. Although the cooperative agreements do not include funds for viral-hepatitis surveillance, the coordinators are good sources of information about surveillance activities being conducted in each jurisdiction. As part of a national assessment of viral-hepatitis surveillance initiatives, the National Copyright © National Academy of Sciences. Hepatitis and Liver Cancer: A National Strategy for Prevention and Control of Hepatitis B and C http://www. Core surveillance means those activities in which all jurisdic- tions must engage to provide accurate, complete, and timely information to monitor incidence, prevalence, and trends in disease diagnoses. Data from other activities, such as targeted surveillance, supplement information from core surveillance, and are necessary to provide accurate incidence estimates, given the challenges of conducting hepatitis B and C surveillance, as de- tailed in this chapter. The recommendations also include guidance regarding the interpretation and dissemination of surveillance data. Federal and state health-department surveillance systems provide population-based information that can be used to improve the public’s health. They also offer an opportunity for public-health interven- tion at the individual level by linking infected people to appropriate care and support services (Klevens et al. Public health surveillance generally involves name-based reporting of cases of specifed diseases to state and local health departments. As such, it requires the gathering of information that some people consider private. Public health offcials and state legislatures have weighed the costs and benefts of public health surveillance and have required name-based report- ing of specifc diseases with confdentiality safeguards in place to protect private information (Fairchild et al. Hepatitis and Liver Cancer: A National Strategy for Prevention and Control of Hepatitis B and C http://www. The data can assist in recognizing and addressing breaches in in- fection control, and they can help to mitigate the size of outbreaks. Research on those outbreaks has shown that they typically occurred in dialysis units, medical wards, nursing homes, surgery wards, and outpatient clinics and resulted from breaches in infection control (Lanini et al. In a 2009 study, researchers found evidence of 33 outbreaks in nonhospital health-care settings in the United States in the last 10 years. Transmission was primarily patient to patient and was caused by lapses in infection control and aseptic techniques that allowed contamination of shared medical devices, such as dialysis machines. The authors stated that successful outbreak control depended on systematic case identifcation and investigation, but most health departments did not have the time, funds, personnel resources, or legal authority to investigate health-care–associated outbreaks (Thompson et al. Hepatitis and Liver Cancer: A National Strategy for Prevention and Control of Hepatitis B and C http://www. For example, estimates of disease burden are commonly used to provide guidance to policy-makers on the level of funding required for disease-related programs.
In this example buy vardenafil 10mg mastercard, thrombolytic therapy complications can vary from serious to mild in severity purchase genuine vardenafil. Chronic disability can also vary from a mild to a constant dis- abling deﬁcit purchase vardenafil 10mg on line, which can be very severe and last for only a brief period of time and then spontaneously resolve. Standard medical treatment may actually result in more patients having only a small amount of residual deﬁcit. This can occur even if a “cure” is The probabilities have been omitted for clarity. You must include all of these outcomes to make this a more realistic model of the situation. Finally, any decision analysis must include a reasonable “time horizon” over which the outcomes should be assessed. Computers can be used to show patients how their personal values for each outcome will change the expected value of each treatment. There are computer programs that have been developed to assist patients in making difﬁcult deci- sions about whether or not to have prostate cancer screening and what options to take if the screening test is positive, but they are not yet commercially avail- able and are currently used only in research programs. The development of user-friendly computerized interfaces will help improve the quality of patient decisions. The doctor must continue to be able to edu- cate his or her patient about the consequences of each action and describe the objective reality of each disease state and treatment options for them so that the Decision analysis and quantifying patient values 343 patient can make appropriate decisions on the utility they want to assign to each outcome. In short, the role of the health-care provider is to give their patients the facts and probability of the outcomes and help the patient decide on their utility for each outcome. Threshold approach to decision making Earlier, in Chapter 26, we talked about the treatment and testing thresholds. The threshold approach to testing and treatment can use decision trees to determine when diagnostic testing should be done. Consider the situation of a patient com- plaining of shortness of breath in whom you suspect a pulmonary embolism or blood clot in the lungs. Should you order a pulmonary angiogram test in which dye is injected into the pulmonary arteries? The test itself is very uncomfortable, causes some complications, and can rarely cause death. There are basically three options: (1) Treat based on clinical examination and give the patient an anticoagulant without doing the test. The treatment threshold is the probability of disease above which a physician should initiate treatment for the disease without ﬁrst doing the test for the dis- ease. This is the level above which, testing will produce an unacceptable number of false negatives and the patient would then be denied the beneﬁts of treatment. This is the prob- ability below which, there are an unacceptable number of false positives and patients would then be unnecessarily exposed to the side effects of treatment. If the post-test probability after a negative test, the false reassurance rate, falls below the test- ing threshold, it was a worthwhile test and the patient does not need treatment. It took the probability of disease from a value of probability at which testing should precede treating, to one at which neither treatment nor further testing is beneﬁcial. If the post-test probability of a bleed is high, standard treatment is likely to be better, since thrombolytic therapy is more likely to lead to increased bleeding in the brain. An exam- ple would be a person with known atrial ﬁbrillation, not on anticoagulants, who had a sudden onset of severe left hemiparesis without a headache. Changing one fact of this pattern would change the probability of a bleed and the ﬁnal decision. At a high pretest probability the clinical picture is so strong that the test shouldn’t be done at all since a false negative is much more likely than a true negative leading to treatment of someone with a potential bleed. An example would be someone with a sudden onset of the worst headache of their life with their only deﬁcit being slight weakness of their non-dominant hand. Here the potential of giving thrombolytic therapy to someone with a bleed is too high and the projected beneﬁt not great enough. Mathematical expression of threshold approach to testing There are formulas for calculating these thresholds, but please don’t memorize them. A false positive test resulting in unnecessary use of risky tests or treatments such as cardiac catheterization or cardiac drugs or a false negative test resulting in unnecessarily withholding beneﬁcial tests or treatments are both adverse out- comes of testing. You can substitute different values of test characteristics, dif- ferent positive and negative predictive values, and different values of the beneﬁt and risk of treatment in a sensitivity analysis of the decision tree and determine what the effect of these changes will be on the utility of each treatment arm. Markov models Another method of making a decision analysis is through the use of Markov mod- els. The difﬁculty with these is that there must be some data on the average time a given individual patient spends in each health state. Ovals are states of health associated with quality measures such as death (U = 0), complete health or cure (U = 1), and other outcomes (U varies from 0 to 1). Arrows are transitions between states or within a state and are attached to probabilities or the likelihood of changing states or remaining in the same state. This type of model is ideal for putting into a computer to get the ﬁnal expected values. Ethical issues Finally, there are signiﬁcant ethical issues raised by the use of decision trees and expected-values decision making. When there are limited resources, is it more just to spend a large amount 346 Essential Evidence-Based Medicine of resources for a small gain? Is a small gain deﬁned as one affecting only a few people or one having only a small health beneﬁt? Some of these questions can be answered using cost-effectiveness analyses and will be covered in the next chapter. The use of a decision tree in making medical decisions can help the patient, provider, and society decide which treatment modality will be most just. Look for treatments that beneﬁt the most people or have the largest overall improve- ment in health outcome. Ethical problems arise when a choice has to be made on whether to consider the best outcome from the perspective of a large popula- tion or the individual patient. If we take the perspective of the individual patient, how are we to know that the treatment will beneﬁt that particular patient, the next patient, or the next 20 patients? Is the decision up to each individual or should the decision be legislated by society? Decision trees allow the provider, society, and the patient to decide which ther- apy is going to be the most beneﬁcial for the most people. Whether decision trees are a mathematical expression of utilitarianism is a hotly debated issue among bioethicists. The basic perspectives of medical care within the tra- ditional patient–physician relationship include medical indications, which are physician-directed, and patient preferences, which are patient-driven. Current or added perspectives modify the decision and include quality of life, which considers the impact on the individual of high-technology interventions and contextual features, which are cultural, societal, family, religious or spiritual, community, and economic fac- tors. These are all part of the discussion between the provider and the patient and form the basis of the provider–patient relationship. Assessing patient values Patient values must be incorporated into medical decision making and health- care policies by providers, government, managed care organizations, and other decision makers. The output of decision trees is variable and ultimately is based on the patient preferences.
Dietary Fiber in the colon can also stimulate bacterial fermentation buy vardenafil with mastercard, which has been associated with increases in calcium order vardenafil mastercard, magnesium vardenafil 10mg without a prescription, and potassium absorption (Demigné et al. Many fiber sources, such as karaya gum, sugar beet fiber, and coarse bran, are also excellent sources of minerals (Behall et al. Several investigators have shown that inulin and fructooligosaccharides actually enhance calcium and magnesium absorption (Coudray et al. There is also indirect evidence of this same enhancement with calcium in humans (Trinidad et al. A direct effect of fiber on mineral absorption has also been reported in humans where inulin increased the apparent absorption and balance of calcium (Coudray et al. Gastrointestinal distress can occur with the consumption of high fiber diets, but this often subsides with time. Epidemiological analysis from 53 devel- oping countries indicated that 56 percent of deaths in young children were due to the potentiating effects of malnutrition in infectious diseases (Pelletier et al. The increased duration or susceptibility to infec- tious diseases such as respiratory infections and diarrhea are due, in part, to the involvement of protein in immune function. Impaired Growth Low protein intake during pregnancy is correlated with a higher inci- dence of low birth weight (King, 2000). These deficits can be corrected by the provision of a high protein diet (Badaloo et al. Low Birth Weight Rush and coworkers (1980) found decreases in both gestational length and birth weight and increases in very early premature births and mortal- ity with high density protein supplementation (additional 40 g/d) in poor, black pregnant women at risk of having low birth weight infants. In contrast, Adams and coworkers (1978) reported no differences from the controls in mean birth weights of infants of mothers at risk of having a low birth weight infant when these women were supplemented with 40 g/d of protein. No reports were found of protein toxicity in healthy pregnant or lactating women that were not at risk of having a low birth weight infant. Risk of Nutritional Inadequacy High quality protein is typically consumed via animal products, and therefore vegetarians may consume less high quality protein than omni- vores. Because animal foods are the primary sources of certain nutrients, such as calcium, vitamin B12, and bioavailable iron and zinc, low protein intakes may result in inadequate intakes of these micronutrients. As an example, Janelle and Barr (1995) reported significantly lower intakes of riboflavin, vitamin B12, and calcium by vegans who also consumed lower amounts of protein (10 versus 15 percent of energy) compared with nonvegetarians. Vegetable protein has been shown to decrease plasma cholesterol con- centrations in experimental animals and humans (Nagata et al. When the ratio of casein:soybean protein in the diet was decreased, there was a reduction in total and non-high density lipoprotein cholesterol concentrations (Fernandez et al. In laboratory animals, it was shown that the onset of atherosclerosis was significantly reduced when animals were fed a textured vegetable protein diet compared to a beef protein diet (Kritchevsky et al. The magnitude of this effect for a doubling of the protein intake, in the absence of change in any other nutrient, is a 50 percent increase in urinary calcium (Heaney, 1993). This has two potential detrimental consequences: loss of bone calcium and increased risk of renal calcium stone formation. Loss of calcium from bone is thought to occur because of bone mineral resorption that provides the buffer for the acid produced by the oxidation of the sulfur amino acids of protein (Barzel and Massey, 1998). However, although increased resorption of bone with increased protein intake has been shown (Kerstetter et al. It has recently been concluded that there may be no need to restrain dietary protein intake. Poor protein status itself leads to bone loss, whereas increased protein intake may lead to increased calcium intake, and bone loss does not occur if calcium intake is adequate (Heaney, 1998). In a recent prospective study of men and women aged 55 to 92 years, consumption of animal protein was positively associated with bone mineral density in women, but not in men (Promislow et al. In contrast, Dawson-Hughes and Harris (2002) reported no association between protein intake and bone mineral density in 342 healthy men and women aged 65 years and older. However, when the individuals were given cal- cium citrate malate and vitamin D in addition to the high protein intake, there was a favorable change in bone mineral density. Kidney Stones It has been estimated that 12 percent of the population in the United States will suffer from a kidney stone at some time (Sierakowski et al. The most common form of kidney stone is composed of calcium oxalate, and its formation is promoted by high concentrations of calcium and oxalate in the urine. A high animal protein intake in healthy humans increases urinary calcium and oxalate and the overall probability of form- ing kidney stones by 250 percent (Robertson et al. Conversely, restricting protein intake improved the lithogenic profile in hypercalciuric patients (Giannini et al. Also, the incidence of calcium oxalate stones has been shown to be associated with consumption of animal pro- tein (Curhan et al. In this study, 50 patients were given low animal protein (56 to 64 g/d) and high fiber, plus adequate fluid and calcium, whereas 49 control patients were only instructed to take adequate water and calcium. However, as protein intake was not the only variable, and in view of the data described above suggesting benefits from lower protein intake, further investigation is necessary. Renal Failure Restriction of dietary protein intake is known to lessen the symptoms of chronic renal insufficiency (Walser, 1992). This raises two related, but distinct questions: Do high protein diets have some role in the develop- ment of chronic renal failure? The concept that protein restriction might delay the deterioration of the kidney with age was based on studies in rats in which low energy or low protein diets attenuated the develop- ment of chronic renal failure (Anderson and Brenner, 1986, 1987). In particular, the decline in kidney function in the rat is mostly due to glomerulosclerosis, whereas in humans it is due mostly to a decline in filtration by nonsclerotic nephrons. Also, when creatinine clearance was measured in men at 10- to 18-year intervals, the decline with age did not correlate with dietary protein intake (Tobin and Spector, 1986). Correla- tion of creatinine clearance with protein intake showed a linear relation- ship with a positive gradient (Lew and Bosch, 1991), suggesting that the low protein intake itself decreased renal function. These factors point to the conclusion that the protein content of the diet is not responsible for the progressive decline in kidney function with age. Coronary Artery Disease It is well documented that high dietary protein in rabbits induces hypercholesterolemia and arteriosclerosis (Czarnecki and Kritchevsky, 1993). However, this effect has not been consistently shown in either swine (Luhman and Beitz, 1993; Pfeuffer et al. In humans, analysis of data from the Nurses’ Health Study showed an inverse relation- ship between protein intake and risk of cardiovascular disease (Hu et al. The association was weak but suggests that high protein intake does not increase the risk of cardiovascular disease. Obesity A number of short-term studies indicate that protein intake exerts a more powerful effect on satiety than either carbohydrate or fat (Hill and Blundell, 1990; Rolls et al. However, some epi- demiological studies have shown a positive correlation between protein intake and body fatness, body mass index, and subscapular skinfold (Buemann et al. In contrast, a 6-month randomized trial demonstrated that the replacement of some dietary carbohydrate by protein improved weight loss as part of a reduced fat diet (Skov et al. Cancer The fact that the growth of tumor cells in culture is often increased by high amino acid concentrations (Breillout et al. Reviews of the literature on colon cancer have concluded that high meat intake may be associated with increased risk, but that high total protein intake is not (Clinton, 1993; Giovannucci and Willett, 1994; Parnaud and Corpet, 1997).