By I. Emet. University of Wisconsin-Green Bay. 2018.
If you have followed the argum ents on m etaanalysis of published trial results this far purchase 1 mg hytrin blood pressure chart stress, you m ight like to read up on the m ore sophisticated technique of m etaanalysis of individual patient data 2mg hytrin overnight delivery blood pressure medication and weight gain, which provides a m ore accurate and precise figure for the point 132 PAPERS TH AT SU M M ARISE OTH ER PAPERS estim ate of effect. In the language of m etaanalysis, hom ogeneity m eans that the results of each individual trial are com patible with the results of any of the others. H om ogeneity can be estim ated at a glance once the trial results have been presented in the form at illustrated in Figures 8. British Regional HeartBritish Regional Heart BUPABUPA GothenburgGothenburg MRFIT screeneesMRFIT screeness Renfrew-PaisleyRenfrew-Paisley WhitehallWhitehall HonoluluHonolulu Central SwedenCentral Sweden IsraeliIsraeli Pooling projectPooling project 0 10 20 30 40 50 % Reduction Figure 8. The definitive test involves a slightly m ore sophisticated statistical m anoeuvre than holding a ruler up against the blobbogram. The one m ost com m only used is a variant of the chi square ( 2) test (see Table 5. The 2 statistic for heterogeneity is explained in m ore detail by Sim on Thom pson,30 who offers the following useful rule of thum b: a 2 statistic has, on average, a value equal to its degrees of freedom (in this case, the num ber of trials in the m etaanalysis m inus one), so a 2 of 7. There m ay, for exam ple, be known differences in m ethodology (for exam ple, authors m ay have used different questionnaires to assess the sym ptom s of depression) or known clinical differences in the trial participants (for exam ple, one centre m ight have been a tertiary referral hospital to which all the sickest patients were referred). There m ay, however, be unknown or unrecorded differences between the trials which the m etaanalyst can only speculate upon until he or she has extracted further details from the trials’ authors. Rem em ber: dem onstrating statistical heterogeneity is a m athem atical exercise and is the job of the statistician but explaining this heterogeneity (i. The results are expressed as the 134 PAPERS TH AT SU M M ARISE OTH ER PAPERS percentage reduction in heart disease risk associated with each 0. The horizontal lines represent the 95% confidence intervals of each result and it is clear, even without being told the 2 statistic of 127, that the trials are highly heterogeneous. The m etaanalyst m ust return to his or her prim ary sources and ask, "In what way was trial A different from trial B, and what do trials C, D and H have in com m on which m akes their results cluster at one extrem e of the figure? In this exam ple, a correction for the age of the trial subjects reduced 2 from 127 to 45. In other words, m uch of the "incom patibility" in the results of these trials can be explained by the fact that em barking on a strategy (such as a special diet) which successfully reduces your cholesterol level will be substantially m ore likely to prevent a heart attack if you are 45 than if you are 85. This, essentially, is the basis of the grievance of Professor H ans Eysenck, who has constructed a vigorous and entertaining critique of the science of m etaanalysis. Eysenck’s reservations about m etaanalysis are borne out in the infam ously discredited m etaanalysis which dem onstrated (wrongly) that there was significant benefit to be had from giving intravenous m agnesium to heart attack victim s. A subsequent m egatrial involving 58000 patients (ISIS-4) failed to find any benefit whatsoever and the m etaanalysts’ m isleading conclusions were subsequently explained in term s of publication bias, m ethodological weaknesses in the sm aller trials, and clinical heterogeneity. As one who tends to side with the splitters, I would put Eysenck’s m isgivings about m etaanalysis high on the list of 135 H OW TO READ A PAPER required reading for the aspiring system atic reviewer. Indeed, I recently threw m y own hat into the ring when Sim on G riffin published a m etaanalysis of prim ary studies into the m anagem ent of diabetes by prim ary health care team s. As I said in m y com m entary on his article, "Four apples and five oranges m akes four apples and five oranges, not nine appleoranges". Fortunately, the two of us have agreed to differ – and on a personal level we rem ain friends. For an authoritative review of the technicalities of integrating heterogeneous pieces of evidence into system atic reviews, see the article by Cindy M ulrow and colleagues. A com parison of results of m eta-analyses of random ised controlled trials and recom m endations of clinical experts. Secondary prevention following stroke or TIA in patients with non-rheum atic atrial fibrillation: anticoagulant therapy versus control. An em pirical study of the possible relation of treatm ent differences to quality scores in controlled random ized clinical trials. Assessing the quality of random ized controlled trials: current issues and future directions. The Cochrane Collaboration: preparing, m aintaining, and dissem inating system atic reviews of the effects of health care. The D elphi list: a criteria list for quality assessm ent of random ized clinical trials for conducting system atic reviews developed by D elphi consensus. Assessing the quality of reports of random ised trials: im plications for the conduct of m eta-analyses. The m iracle of D ICE therapy for acute stroke: fact or fictional product of subgroup analysis?
Objects in static equilibrium: the Pisa tower (a) hytrin 2mg generic pulse pressure graph, and a ballerina (b) holding a delicate balance on the toes of her one foot order hytrin 1 mg mastercard prehypertension 23 years old. The symbol W usually denotes the weight of a body and N is the ground force exerted on the body. The magnitude of acceleration will be equal to the magnitude of the resultant (unbalanced) force divided by the mass of the object. If an object is at rest or moving with constant velocity, the resultant force act- ing on the object must be equal to zero. Could the gravitational force acting on an object depend on the mo- tion of the object? These are some of the pertinent questions physicists had to consider before formulating the laws of motion. In his famous book Principia (1687), Newton wrote that he considered forces mathematically and not physically. But later on, he was compelled to admit their physical reality, for no true physics could be constructed without them. Newton’s third law states that for every action, there is an equal and opposite reaction. That is, a force on object 1 caused by interactions with object 2 is equal and opposite to the force on object 2 caused by the in- teractions with object 1. It is difficult to imagine, when a boxer hits a slender person half his weight, that he is automatically hit back with the same intensity of force (Fig. Newton’s third law states that the force of reaction is equal in mag- nitude and opposite in direction to the force of action. A boxer who hits an ordi- nary man is hit back with a force of the same intensity but opposite in direction, regardless of the size and the strength of the man (a). Two people who are arm wrestling exert on one another forces of equal magnitude but opposite direction (b). When two pendulums collide, they exert on each other forces of equal mag- nitude (c). When a person beats another in arm wrestling, the force he exerts on the opposing party has the same level of intensity as the force the losing party exerts on him (Fig. It is just that the winning party is able to continue to contract his biceps muscles while the biceps of the opposing person is yielding to the external load. The third law may be counterintuitive also because we rarely observe equality in nature—things are either bigger or smaller, heavier or lighter, and so on. Newton arrived at this counterintuitive law by considering the data on the impact of two pendulums (Fig. Hence, the discovery that in our universe equality exists, at least within the realm of contact forces. Magnificent structures built by men thousands of years ago suggest that ancient civilizations were at least intuitively aware of many of the subtle features of the laws of motion. However, it took many millennia for a human to state these laws in an explicit and concise manner. Greek philosophers, among them Aristotle, had attempted to formulate the physical laws of motion but they all failed. They had held to the belief that the fundamental principles of nature could be deduced only by ra- tional thinking and not by experimentation. As a result, they did not re- alize that quantities such as force, velocity, and acceleration have both magnitude and direction and as such they differ fundamentally from scalar entities such as mass and temperature. The importance of empirical observation in the discovery of physical laws was appreciated much later during the Renaissance Period by Galileo and others. It was Galileo in the seventeenth century who first formu- lated the parallelogram law for combining vectors such as forces acting on a particle. It was Kepler who first observed a clear illustration of New- ton’s third law while investigating the motion of stars. Kepler concluded that gravitational force between two stars was proportional to the mass of each star and inversely proportional to the square of the distance be- tween them. The gravitational force had to be aligned on the straight line connecting the centers of the two stars. And, regardless of their mass, any two stars exerted on each other the same amount of force, with direction reversed. Development of calculus and vector differentiation in the sev- enteenth century led finally to the emergence of the branch of science that we call today classical mechanics.
A method that allows the clinician to assess the temporal relationship between pain and psycho- The clinical interview can take either a structured or logical factors is a pain diary hytrin 1mg mastercard blood pressure chart in pdf. With structured interviews hytrin 1 mg for sale arteria hypogastrica, ment of the actual occurrence of target behaviours, in a set number of questions are asked, which assess core addition to helping reduce response bias and error in elements of interest. Information is collated and used to produce the clinician usually has a set of speciﬁc objectives (e. For example, ascertain pain behaviours), but also has much greater diaries are used to help ascertain uptime/downtime. Clinical interviews can also focus such diaries on more than one occasion during the speciﬁcally on certain areas of interest. Cardiovascular events, such • Emotions, behaviour and cognition should be included as heart rate and blood pressure, are also believed in the evaluation of pain patients. Subjective measures of pain evaluation include self- to reﬂect changes in underlying emotional states. Interestingly, blood pressure is inversely related to • Objective measures include behavioural observation pain sensitivity, in that hypertensives and normoten- and psychophysiological methods. Other cardiovascular-related indices key information at speciﬁed times during the day. One of the most basic methods of measuring pain behaviours is to observe what people actually do. People Key points in pain will often communicate their pain experiences in a non-verbal manner, whether this is through body • Pain is a subjective multidimensional construct. Such non-verbal • Psychological processes, such as emotions, cogni- behaviours are particularly useful for the clinician tion and behaviour, inﬂuence the perception and working with groups that are unable to easily verbally experience of pain. However, observation can be a time- logical processes is critical to our understanding consuming exercise, in that some effort is needed to and ultimate management of pain. There are also important issues associated with measurement; in an ideal situa- tion patients are videotaped engaging in various behav- Further reading iours, which are then rated by trained observers. Psychological Mechanisms of Pain and of the individual can be measured via objective physi- Analgesia. Fear-avoidance and measures is skin conductance, which varies wit its consequences in chronic musculoskeletal pain: a state of changes in sweat gland activity in response to emotional the art. PART PAIN IN THE CLINICAL SETTING 3 3a CLINICAL PRESENTATIONS 97 14 EPIDEMIOLOGY OF PAIN 99 W. Macrae Introduction inability to deﬁne the population from which the patients are drawn. Surveys based in general practice Epidemiology is the study of the distribution and give a better indication of the size of the problem, but determinants of diseases and the application of the have been hampered by an inability to agree standard ﬁndings to the control of health problems. One study showed that 63% of patients ing the distribution of a disease we can learn about: who attended general practitioners (GPs) for whatever reason had pain. However, the results vary from 7% to 82%, Epidemiology has various applications: mainly because different deﬁnitions were used. The problem of pain suffered by patients in hospital • Planning and evaluating services. In a third of these the pain was present – Tertiary: minimising impairment and disability. In over 40% of cases, patients had to request analgesia and the drugs did not arrive immediately. Epidemiological studies of pain Gender, age and pain The ﬁrst step in the study of a disease is to deﬁne the population group and develop a valid set of diagnostic There is no simple relationship between gender and criteria. Not only does the pattern vary across different on the general problem of pain as a whole and of conditions, but also across different age groups. Surgery and other painful proce- Prevalence is the number of cases of a given disease dures were routinely performed on neonates and • in a given population at a designated time (e. Thanks to the tireless efforts of a small group of basic scientists and clinicians the position has improved in recent years.
Before using the scale see if they can grasp the concept of sensing the exercise responses (breath- ing 2mg hytrin with visa blood pressure medication drug interactions, muscle movement/strain purchase 1 mg hytrin blood pressure 210 over 110, joint movement/speed). Anchor the perceptual range, which includes relating to the fact that no exertion at all is sitting still, and maximal exertion is a theoretical concept of pushing the body to its absolute physical limits. Patients should then be exposed to differing levels of exercise intensity (as in an incremental test or during an exercise session) so as to understand what the various levels on the scale feel like. Just giving them one or two points on the scale to aim for will probably result in a great deal of variability. Use the above points to explain the nature of the scale and explain that the patient should consider both the verbal descriptor and the numerical value. They should ﬁrst concentrate on the sensations arising from the activity, look at the scale to see which verbal descriptor relates to the effort they are experiencing and then link it to the numerical value. Make sure the patient is not just concentrating on singular sensations, known as differentiated ratings (see Figure 3. Differentiated ratings can be used during muscular strength activity or where exercise is limited more by breathlessness or leg pain, and not cardiac limitations, as in the case pulmonary or peripheral vascular disease, respectively. There are three important cases where the patient may give an incorrect rating: a. When the patient already has a preconceived idea about what exertion level is elicited by a speciﬁc activity (Borg, 1998). He/she is not aware that what is required is to rate the amount of effort at this very moment, not what they think a typical level of exertion is for that activity. Similar to heart rate, RPEs should be taken while the patient is actually engaged in the movements, not after they have ﬁnished or in the break between stations. Simply pleasing the exercise practitioner by stating what should be the appropriate level is a regular observation in the author’s experience. In the early stages of rehabilitation, the patient’s exercise inten- sity should be set by HR or workrate (e. Once it has been established that the patient’s rating concurs with the target heart rate or MET level reliably, moving them on to production mode can be considered. It is known that endurance athletes in a race situation work very hard mentally to concentrate (cognitively associate) on their sen- sations in order to regulate their pace effectively (Morgan, 2000). ESTIMATED METABOLIC EQUIVALENTS The metabolic equivalent (MET) is widely used in cardiovascular population exercise guidelines as a means of quantifying the energy demands of physical activity. It relates the rate of the body’s oxygen uptake (VO2) for a given activ- ity as a multiple of an individual’s resting VO2. It is important to recog- nise that these values are estimates, which means that each individual patient could be working above or below this estimate. The variability of the estimate depends on the simplicity or complexity of the movements. For example, the variability of pedalling an exercise cycle ergometer will likely be less than that of stepping or walking. The motor skill involved in cycle ergometry is ﬁxed by the motion of the pedal crank and mainly involves the legs. Stepping and walking require the individual to balance and use arm and trunk motions, which can vary much more than cycling. In cardiac rehabilitation, the MET values from the patients’ exercise ECG stress test are typically reported. These data provide the exercise leader with information of both intensity and functional capacity. It should be noted, if the ETT is carried out using a motorised treadmill, how much the MET value can be altered by the patient holding on to the handrail. Astrand (1982) reported that when walking on the treadmill with hands on the rail, the VO2 was as much as 9ml. Most patients attending an exercise ECG stress test will hold on to the rail because 82 Exercise Leadership in Cardiac Rehabilitation they are typically unfamiliar with treadmill exercise and are not used to a moving platform. In addition treadmill walking mechanics are very different from ﬂoor walking, making direct comparison of ﬂoor to treadmill walking questionable. For box-stepping exercise performed in healthy young individuals, the vari- ability (based on the 95% limits of agreement) in the estimated versus actual MET (VO ) values was found to be up to 1.
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