By W. Reto. Westwood College of Technology. 2018.
Secondary analysis is a re-analysis of the original data either using another statistical technique or answering new questions with previously obtained data differin 15 gr. It is a summary of all pri- mary research on a given topic and it may provide good background information 367 368 Essential Evidence-Based Medicine that is more up to date than a textbook discount differin 15 gr with amex. But review articles have the disadvantage of being somewhat subjective and reﬂecting the biases of the author, who may be very selective of the articles chosen for review. One must be knowledgeable of the literature being reviewed in order to evaluate this type of article critically. Typically, a meta-analysis looks at data from multiple studies of the same clinical question and uses a variety of statistical techniques to integrate their ﬁndings. It may be called a quantitative systematic review and represents the rigorous application of research techniques and statistical analysis to present an overview of a given topic. It can help uncover a single study which has totally different results because of systematic error or bias in the research process. For example, multiple small trials done before 1971 showed both positive and negative effects of light or phototherapy on hyperbilirubinemia in newborns. Occasionally a large trial shows an opposite effect from that found in multiple small trials. This is often due to procedural or methodologic study design differ- ences in the trials. However, as a general rule, correctly done large cooperative trials are more reliable than meta-analysis of many smaller trials. The use of meta-analysis does not reduce the need for large well-done studies of primary clinical modalities. Guidelines for evaluation of systematic reviews Were the question and methods clearly stated and were comprehensive search methods used to locate relevant studies? In meta-analysis, the process of article selection and analysis should proceed by a preset protocol. By not changing the process in mid-analysis the author’s bias and retrospective bias are minimized. This means that the deﬁnitions of outcome and predictor or therapy variables of the analysis are not changed in Meta-analysis and systematic reviews 369 mid-stream. The research question must be clearly deﬁned, including a deﬁned patient population and clear and consistent deﬁnitions of the disease, interven- tions, and outcomes. A carefully deﬁned search strategy must be used to detect and prevent publi- cation bias. This bias occurs because trials with positive results and those with large sample sizes are more likely to be published. The bibliographies of all relevant articles found should be hand searched to ﬁnd any misclassiﬁed articles that were missed in the origi- nal search. The authors must cite where they looked and should be exhaustive in look- ing for unpublished studies. Not using foreign studies may introduce bias since some foreign studies are published in English-language journals while others may be missed. The authors should also contact the authors of all the studies found and ask them about other researchers working in the area who may have unpublished studies available. Also, the National Library of Medicine and the National Institutes of Health in the United States have an online repository of clinical tri- als called www. Were explicit methods used to determine which articles to include in the review and were the selection and assessment of the methodologic quality of the primary studies reproducible and free from bias? Objective selection of articles for the meta-analysis should be clearly laid out and include inclusion and exclusion criteria. This includes a clearly deﬁned research and abstraction method and a scoring system for assessing the quality of the included studies. The publication status may sug- gest stronger studies in that those that were never published or only published in abstract form may be signiﬁcantly deﬁcient in methodological areas. A well-designed obser- vational study with appropriate safeguards to prevent or minimize bias and con- founding, will also give very strong results. The methods of meta-analysis include ranking or grading the quality of the evidence. The study sites and patient populations of the individual studies may limit generalizability of the meta-analysis. We will discuss issues of how to judge homogeneity and combine heterogeneous studies. Independent review of the methods section looks at inclusion and exclusion criteria, coding, and replication issues. There must be accurate and objective abstraction of the data, ideally done by blinded abstracters. Two abstracters should gather the data independently and the author should check for inter- rater agreement.
Some oral suspensions must be kept refrigerated purchase differin 15 gr otc; their storage at room temperature is limited to a few days differin 15 gr fast delivery, and with syrups there is a risk of fermentation. Confusion between cough mixtures and antibacterial suspensions or syrups is common. Even using a powder for subsequent reconstitution, the costs may be 2 to 7 times higher than an equivalent dose due to the cost of the bottle itself and higher transportation costs due to weight and volume. The shortest and least divided (1 to 2 doses per day) treatments are most often recommended. Considering non-essential medicines and placebos In developing countries as in industrialised countries, patients with psychosomatic complaints are numerous. The problems that motivate their consultations may not necessarily be remedied with a drug prescription. Is it always possible or desirable to send these patients home without a prescription for a symptomatic drugs or placebo? When national drug policy is strict and allows neither the use of placebos nor non-essential symptomatic drugs, other products are often used in an abusive manner, such as chloroquine, aspirin, and even antibacterials. This risk is real, but seems less frequent, which makes the introduction of placebos on a list of essential drugs relevant. Their composition generally corresponds to preventive treatment of vitamin deficiency and they have no contra–indications. Numerous non-prescription drug products (tonics, oral liver treatments presented in ampoules) have no therapeutic value and, due to their price, cannot be used as placebos. Disinfectants are used to kill or eliminate microorganisms and/or inactivate virus on inanimate objects and surfaces (medical devices, instruments, equipment, walls, floors). Certain products are used both as an antiseptic and as a disinfectant (see specific information for each product). Selection Recommended products 1) Core list No single product can meet all the needs of a medical facility with respect to cleaning, disinfection and antisepsis. However, use of a limited selection of products allows greater familiarity by users with the products in question and facilitates stock management: – ordinary soap; – a detergent and, if available, a detergent-disinfectant for instruments and a detergent- disinfectant for floors and surfaces; – a disinfectant: chlorine-releasing compound (e. Alcohol acts faster than polyvidone iodine, but its duration of action is shorter. Application to mucous membranes or broken skin is contra-indicated, however, alcohol may be used on broken skin in the event of accidental exposure to blood. For example, for antiseptic hand rub, depending on the product specifications: • Bactericidal effect may be achieved with a single application of 30 seconds duration, or 2 consecutive applications of 30 seconds each, or a single application of 60 seconds duration. For surgical activity, ensure that the product is suitable for use as a surgical hand rub. Precautions should be taken during storage and use to avoid contact with a heat source (flame, electrocautery, etc. Given the possible interactions between different groups of antiseptics, antiseptic cleansing and antisepsis should only be carried out using products from the same class. Instructions for glutaraldehyde use must be followed scrupulously: 1) two preliminary washes of the equipment through immersion in a detergent-disinfectant solution for instruments, followed each time by rinsing; 2) complete immersion of the equipment in a 2% glutataldehyde solution for 20 minutes; 3) thorough final rinsing, with filtered water (or sterile water for endoscopes introduced into a sterile cavity) to eliminate any residue; 4) thorough drying with a sterile towel; 5) sterile wrapping and use within 24 hours. Glutaraldehyde solution is irritating to skin and mucous membranes, and releases toxic vapours. Personnel exposed to glutaraldehyde should take precautions to protect skin and eyes and avoid inhalation of vapours (risk of nausea, headache, breathing disorders, rhinitis, eye irritation, dermatitis). Precautions should be taken during storage and use to avoid contact with a heat source. Non-recommended products – Hydrogen peroxide (3% or 10 volumes) has limited efficacy as antiseptic agent but can be useful to clean contaminated wounds. To avoid this, the following precautions must be taken: – Prepare all aqueous antiseptic solutions with clean water that has been boiled for a few minutes and cooled. Every medical facility should define a clear policy concerning the renewal of antiseptic solutions. Use – Do not use antiseptic solutions belonging to different classes for the same procedure: incompatibilities between different compounds exist. No evidence exists that antiseptics reduce the risk of transmission, however, their use – after thorough cleaning – is not contraindicated. If an antiseptic is used despite this recommendation, it must be allowed to dry before vaccine injection. Preparation and use of disinfectant solutions The effectiveness of disinfection can be impaired by error in preparation (concentration, temperature), failure to follow recommended contact times, or deterioration of the product due to poor storages conditions. Personnel carrying out disinfection should wear protective clothing when preparing or using disinfectant solutions: gown, rubber apron, gloves with long cuffs, goggles and mask. Preparation Solutions should be prepared with clean water (chlorine solutions should be prepared with cold water only, in non-metal containers).
When evidence-based practice guidelines are written buy differin 15gr with mastercard, reviewed differin 15 gr discount, and based upon solid high-quality evidence, they should be implemented by all physicians. However, there are “darker” consequences that accompany the use of prac- tice guidelines. Cur- rently several specialty boards use chart-review processes as part of their spe- cialty recertiﬁcation process. Performance criteria can be used as incentives in the determination of merit pay or bonuses, a process called Pay for Performance (P4P). In the last 30 years there has been an increase in the use of practice guide- lines in determining the proper utilization of hospital beds. Utilization review has resulted in the reduction of hospital stays, which occurred in most cases 322 Essential Evidence-Based Medicine Table 29. Desirable attributes of a clinical guideline (1) Accurate the methods used must be based on good-quality evidence (2) Accountable the readers (users) must be able to evaluate the guideline for themselves (3) Evaluable the readers must be able to evaluate the health and ﬁscal consequences of applying the guideline (4) Facilitate resolution of the sources of disagreement should be able to be conﬂict identiﬁed, addressed, and corrected (5) Facilitate application the guidelines must be able to be applied to the individual patient situation without any increase in mortality or morbidity. The process of utilization review is strongly supported by managed care organizations and third-party payors. The guidelines upon which these rules are based ought to be evidence-based (Table 29. Ideally a panel of interested physicians is assembled and collects the evidence for and against the use of a particular set of diagnostic or therapeutic maneuvers. Some guidelines are simply consensus- or expert-based and the results may not be consistent with the best available evidence. When evaluating a guideline it ought to be possible to determine the process by which the guideline was developed. These domains are: scope and purpose of the guideline, stakeholder involvement, rigor of development, clarity and presentation, applicability and editorial independence. This process only indirectly assesses the quality of the studies that make up the evidence used to create the guideline. There are several general issues that should be evaluated when appraising the validity of a practice guideline. They should be those outcomes that will matter to patients and all relevant outcomes should be included in the guideline. This must include explicit descriptions of the manner in which the evidence was col- lected, evaluated, and combined. The magnitudes of beneﬁts and risks should be estimated and beneﬁts com- pared to harms. This must include the interests of all parties involved in provid- ing care for the patient. These are the patient, health-care providers, third-party payors, and society at large. The preferences assigned to the outcomes should reﬂect those of the people or patients who will receive those outcomes. The costs both economic and non-economic should be estimated and the net health beneﬁts compared to the costs of providing that beneﬁt. Alternative pro- cedures should be compared to the standard therapies in order to determine the best therapy. Finally, the analysis of the guideline must incorporate reason- able variations in care provided by reasonable clinicians. A sensitivity analysis accounting for this reasonable variation must be part of the guideline. Once a guideline is developed, physicians who will use this guideline in prac- tice must evaluate its use. For example, in 1992 a clinical guideline was developed for the management of children aged 3 to 36 months with fever but no resources to detect and treat occult bacteremia. This guideline was published simultane- ously in the professional journals Annals of Emergency Medicine and Pediatrics. After a few years, the guideline was only selectively used by pediatricians, but almost universally used by emergency physicians. The pediatricians are able to closely follow their febrile kids while emergency physicians are unable to do this. Therefore, emergency physicians felt better doing more testing and treating of febrile children in the belief that they would prevent serious sequelae. This guideline has been removed since most of the children in this age group are now immunized against the worst bacteria causing occult bacteremia, hemophilus and pneumococcus. Even if a practice guideline is validated and generally accepted by most physi- cians, there may still be a delay in the general acceptance of this guideline. Physicians’ behavior has been studied and cer- tain interventions have been found to change behavior. These include direct intervention such as reminders on a computer or ordering forms for drugs or diagnostic tests, follow-up by allied health-care personnel, and education from opinion leaders in their ﬁeld. One of the most effective interventions involved using prompts on a computer when ordering tests or drugs. These resulted in improved drug-ordering practices and long-term changes in physician behav- ior.
The relative risks of death for people with fruit and vegetable intake in quintiles 2–5 were 1 buy differin 15gr overnight delivery. An inverse association between fruit and vegetable intake and coronary artery disease was observed among African Ameri- cans but not among Whites (P for interaction = 0 buy differin 15 gr without a prescription. The risk of ischaemic stroke was not signiﬁ- cantly related to consumption of whole grains, reﬁned grains, or fruit and vegetables. In a prospective cohort study of 40 349 Japanese men and women followed up for 18 years (188), daily consumption of green and yellow vegetables and fruits was associated with a lower risk of stroke, intracerebral haemorrhage, and cerebral infarction mortality in both men and women. A recent meta-analysis of 10 prospective cohort studies (189) has also shown that the consumption of ﬁbre from cereals and fruits is inversely associated with risk of coronary heart disease. On the basis of the available evidence, a daily intake of at least 400 g of fruit and vegetables is recommended (86). However, much of this evidence is from observational studies, in which control for potential confounding factors, in particular socioeconomic position, is often inadequate. A cardioprotective diet should consist of a variety of foods, and should aim to achieve four major goals: a healthy overall diet, a healthy body weight, a desirable lipid proﬁle, and a desirable blood pressure. There is strong observational evidence that reducing intakes of total fat (to less than 30% of calories), saturated fat (to less than 10% of calories), and salt (to less than 5 g or 90 mmol per day), and increasing fruits and vegetables (to 400–500 g daily) are likely to be beneﬁcial. Applying these principles to develop diets that match individual preferences and local customs, and demon- strating their effectiveness in reducing cardiovascular risk, are important priorities for research. Advice was focused largely on decreasing intake of salt and fat and increasing intake of fruits, vegetables and ﬁbre. Interventions included one-to-one advice, group sessions and written materials, and ranged in intensity from a single contact to multiple contacts over several years. Of the 23 trials reviewed, nine enrolled participants on the basis of screening for cardiovascular disease risk factors. The majority of studies involved interventions in health care settings; other settings included workplaces, community centres and homes. Greater effectiveness was observed among individuals told they were at greater risk of heart disease, and in interventions with greater intensity and duration. The authors estimated that the summary effects of the dietary interventions reviewed could reduce incidence of coronary heart disease by 12% and of stroke by 11%. This estimate is based on the assumption that dietary changes are sustained, and that the relative risk reductions attributable to changes in cholesterol and diastolic blood pressure can be combined additively. Evidence It has been estimated that inadequate physical activity is responsible for about one-third of deaths due to coronary heart disease and type 2 diabetes (191). There is evidence from observational studies that leisure-time physical activity is associated with reduced cardiovascular risk and cardio- vascular mortality in both men and women (192–194) and in middle-aged and older individuals (195, 196). Several meta-analyses have examined the association between physical activity and cardiovascular disease (197–202). Berlin & Colditz (200) found a summary relative risk of death from coronary heart disease of 1. A meta-analysis of studies in women showed that physical activity was associated with a reduced risk of overall cardiovascular disease, coronary heart disease and stroke, in a dose–response fashion (197). Physical activity improves endothelial function, which enhances vasodilatation and vasomotor function in the blood vessels (199). In addition, physical activity contributes to weight loss, glycaemic control (203, 204), improved blood pressure (205), lipid proﬁle (206–208) and insulin sensitivity (209). The possible beneﬁcial effects of physical activity on cardiovascular risk may be mediated, at least in part, through these effects on intermediate risk factors. Physical inactivity and low physical ﬁtness are independent predictors of mortality in people with type 2 diabetes (210). Overall, the evidence points to the beneﬁt of continued regular moderate physical activity, which does not need to be strenuous or prolonged, and can include daily leisure activities, such as walking or gardening (197). Studies indicate a dose–response relationship between overall physical activity and cardiovascular disease, which is linear at least up to a certain level of activity. Two reviews support the effectiveness of interventions to promote physical activity in the health care setting. Speciﬁc interventions included individual and group counselling, self-directed or prescribed physical activity, supervised and unsupervised physical activity, home- or facility-based physical activity, face-to-face and telephone support, written materi- als, and self-monitoring. Interventions were conducted by one or several practitioners, including physicians, nurses, health educators and exercise leaders. Of the seventeen trials reviewed, eight took place in the primary health care setting. The second review considered only studies in the primary health care setting, and found that brief interventions to promote physical activity produced moderate short-term improvements in self-reported physical activity levels (214). In both reviews, it was noted that the length of follow-up of the studies (typically 1 year or less) was insufﬁ- cient to draw conclusions about long-term effectiveness or whether outcomes would be maintained.