bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prescribing and formularies
Authors: Reilly Philip 
Published: November 2023

Abstract
There is no longer any doubt that audits of general practice prescribing in the UK will happen. The introduction of an indicative prescribing budget for each practice means that a crude form of external audit of prescribing is now in place. In such monitoring, cost is, of course, an immediate and important concern. The steeply rising expenditure on medications over recent years ensured that cost above all else would be considered in the health service reforms as they affect prescribing. UK prescribers are parsimonious in comparison to other similarly developed countries, but the large variation in the cost and frequency of prescribing by practices which were otherwise similar has interested the Government, which naturally sees the financial advantages of all practices behaving in the same way as the cheapest. The fact that such variations were and remain difficult to explain is only now being addressed. Little in medical education prepares the doctor for prescribing in general practice. Young doctors have been thoroughly prepared theoretically and pharmacologically, but are unprepared either for the range of pathology or for some of the apparently irrational pressures to prescribe which occur in primary health care. Many older doctors fail to stay in touch with the rapidly changing field of modern therapeutics.
Problem-solving audits
Authors: Lawrence Martin 
Published: November 2023

Abstract
‘Problems’, writes Baker (1990), ‘can be thought of as deficiencies that those in the practice think are so important that corrective action must be taken’. He goes on to express the view that audits done in response to acknowledged problems usually result in change, those done for curiosity or under compulsion are less likely to do so. Since the prime aim of audit is to improve care, this implies that problem-solving audits are likely to be the most fruitful. Significant event analysis and problem solving have a great deal in common. The former can be construed as formal review of a specific incident, seeking changes which might enable a similar situation to be handled better in future; the latter as an investigation set up to analyse a problem—which may indeed have been revealed by an event.
Access, availability, and continuity
Authors: Freeman George 
Published: November 2023

Abstract
General practice should offer both accessibility and continuity. The patient should find it an easy matter to see the doctor or other primary care team member at a convenient time. Care should be as continuous as required, that is consistent and uninterrupted. Since so much of general practice is based on interpersonal relationships, continuity tends to mean seeing the same person—any alternative implies a very high degree of communication between members of the care team, including the keeping of excellent records. In the archetypal single-handed practice the practitioner was available for long hours and access was by corning and queuing. The patients always saw the same person, so continuity was only limited by the doctor’s memory. Nowadays doctors work in groups with paramedical colleagues. Availability is negotiated through receptionists who operate an appointments system for most contacts with health team members. Although this was originally an attempt to eliminate queuing, appointments systems are also used to even out demand over a number of consulting sessions. The effect may limit both availability and continuity.
Assessment of patients’ views in primary care
Authors: Fitzpatrick Ray 
Published: November 2023

Abstract
The new contract requires family practitioner committees to carry out surveys to assess patients’ views of their general practice services. At the same time it is now expected that patients’ views should be included in medical audit in primary care. This chapter considers some of the methods involved. Whilst indicating the potential value and scope of consumer surveys, the chapter also discusses the potential pitfalls and problems that are frequently encountered. First, it is important briefly to clarify the different reasons why the importance of patients’ views has been so much emphasized in recent policy documents about the health service. One factor is the growing acceptance that the patient provides an important indicator of the quality of care. Indeed, in many aspects of primary care, such as the accessibility of the practice, the receptionist’s manner, or the availability of out of hours care, the patient’s views may be one of the main indicators of quality.
The same equations, different model
Authors: Cruickshank Steven 
Published: November 2023

Abstract
The gas laws are empirically derived descriptions of the behaviour of real gases, They are only approximately true for real gases and the laws break down seriously at extremes of temperature and pressure, They can be explained in terms of the kinetic theory of gases and thermodynamics, and modifications of the fundamental model have been made to improve the correspondence with reality; for exam,, ple, Van der Waals’ equation. The purpose of introducing them here is that they give rise to a model which is identical to that which we have just developed from first principles in describing the relationship of VA and Paco2.
Q by dye-dilution
Authors: Cruickshank Steven 
Published: November 2023

Abstract
The Fick methods for cardiac output determination involving 02 uptake and CO2 output are clearly steady state methods. The universally applied method in clinical practice now is thermodilution using a cardiac output computer. This is a development of the older dye-dilution method in which a dye is injected rapidly into the pulmonary artery and its concentration in blood drawn intermittently from a peripheral artery over the ensuring minute or so is determined. Alternatively, blood was drawn at constant rate from the artery and passed through a densitometer charnber. A typical (simulated) record of the dye-dilution method is shown and it is evident that dye concentration is not in steady state.
The Kety-Schmidt method for cerebral blood flow (CBF)
Authors: Cruickshank Steven 
Published: November 2023

Abstract
The measurement of cerebral blood flow (CBF) is accomplished using the same flux principles as cardiac output. The classical method is that of Kety and Schmidt, using N2O uptake into the brain. More modern methods using radioactive isotopes such as Xenon are merely modifications of the earlier method. The fluxoid idea should make this easy to understand.
Pre-oxygenation: washing out the nitrogen
Authors: Cruickshank Steven 
Published: November 2023

Abstract
As we have already seen, the technique of pre-oxygenation can be of literally vital importance. The process involves replacing the nitrogen in the lung with oxygen so that the oxygen store is augmented, and we have already seen the effectiveness of this. But how rapidly do we expect to be able to achieve the replacement of nitrogen with oxygen? We can model this as an extension of the models that we have already encountered. Although details of technique (e.g. the ability to maintain an air-tight seal with a face mask) will have an important influence, it is useful to have a semi-quantitative idea of how rapidly changes in concentration occur under ideal conditions. This turns out to be a simple matter requiring only application of a ‘rule of thumb’ (and some mild mental arithmetic) if the underlying processes are understood; and, very importantly, the ideas are transferable to many other analogous circumstances.
Standardizing the rate
Authors: Cruickshank Steven 
Published: November 2023

Abstract
The rate of the exponential process in the N2 washout was determined entirely by the ratio of flow ( VA) to volume ( VFRC). No other factors are important in the simple model. We can standardize any simple wash-in or washout exponential process in which there is a flow Q into a container of volume V, by a device, the time constant T. The time constant is the time required for the flow to fill the container. What constitutes the flow and what the container is will vary from circumstance to circumstance, but the principle remains intact. The time constant enables us to use a ‘rule of thumb’ to estimate the magnitude of the change that has occurred.
Invasive blood pressure measurement
Authors: Cruickshank Steven 
Published: November 2023

Abstract
We have spent some time modelling naturally oscillating systems, and we have seen how they respond to a displacement from their equilibrium position in the face of various levels of damping. We now need to look at how such systems respond to an applied vibration from outside. We will concentrate on the implications for invasive blood pressure measurement, but there are many circumstances in which we apply an oscillating force to a real system-high-frequency ventilation is another example.
Constant function
Authors: Cruickshank Steven 
Published: November 2023

Abstract
This is the graph of a function whatever TCP we choose, the graph gives a (constant) unique value for the CSF production. The reality of control of CSF flow will, of course, be more complex. The rule for a constant A function may have different rules for different parts of its input. The CSF uptake is modelled as constant for part of its input and by a linear function for the rest. CSF uptake is a variable. We shall see plenty of examples of the use of constants. Often, these will be constant functions of time. By definition modelling of steady states produces constant functions with respect to time. Other quantities are constant only under specified conditions:
Numerical methods for differential equations
Authors: Cruickshank Steven 
Published: November 2023

Abstract
We have studied some models which have given us ODEs that we have been able to solve. ‘Solve’ here means we were able to find a function the rate of change of which is given by the ODE. We cannot always find a function that satisfies the ODE and the pulmonary air embolism (1.12) problem was an example of this; the problem was real enough, and we would like to know the solution-but we cannot find one. All is not lost, however; if we know the rate of change (from the ODE) and a starting value (an initial condition), we can produce an approximate graph of the function that we require. We demonstrate this with a known uncomplicated function, so that we can compare the real and approximate solution.
Probability models and simulation
Authors: Cruickshank Steven 
Published: November 2023

Abstract
Probability distributions are functions and are used as models for problems involving random processes in exactly the same way as the other functions in the deterministic physiological models that we have developed. Just as we saw certain patterns arising in the physiological modelling, in probabilistic models certain patterns turn up frequently. Modelling assumptions are made which lead to probability models. These can then be used to make rational decisions about proble111s in which chance plays a part, or to make estimates of quantities with defined levels of certainty.
Waiting times in a Poisson process
Authors: Cruickshank Steven 
Published: November 2023

Abstract
We are beginning to feel more familiar with Poisson processes, so let us stay with them a little longer but look now at a different aspect. If we return yet again to the anaphylaxis example, we might ask how long we would expect to wait between one reaction and the next. Again it is simple to state that, since the expected number annually is five, then we expect to wait 0.2 years-about 73 days on average. Since the process is random, however, we know that there will be a spread of waiting times. We have exactly the same circumstance, but we are asking a different question about the situation. Whereas previously we were counting events in a given time, now we are measuring times between those same events. The distinction between counting and measuring is an important one.
Passing the fellowship examination
Authors: Cruickshank Steven 
Published: November 2023

Abstract
Suppose that we have eight candidates taking the fellowship exam and there is a published pass rate of about 30%. Each individual’s exam is a ‘trial’ and passing the test is a ‘success’. ‘Success’ and ‘trial’ are technical terms in probability theory and are obviously very appropriate here. We suppose that one candidate’s success is independent of another’s-no cheating. We expect 2.4 candidates to pass, but obviously the realization will be different-only a whole number can pass. We would probably say that two was the most likely number, since this is the integer closest to 2.4.
Measuring SVP: the normal distribution
Authors: Cruickshank Steven 
Published: November 2023

Abstract
A pharmaceutical manufacturer has produced a new volatile anaesthetic agent and, in order to deliver it by vaporizer, needs to establish a value for the saturated vapour pressure (SVP) at 20°C. The SVP of a substance at any fixed temperature is a physical constant-it has no inherent variability. Unfortunately, the measurement method itself is subject to error, and even though the laboratory might control the experimental conditions as well as possible, there is always some variability in the measurement. The manufacturer has been using the same method for a long while, and knows that on average 95% of the SVP measurements fall within 8 mmHg to either side of the mean value.
Modelling with random variables
Authors: Cruickshank Steven 
Published: November 2023

Abstract
We have seen examples of a number of situations in which random factors are operating and we have introduced four different patterns of variability-the Poisson, exponential, binomial, and normal distributions. These distributions are expressions of the behaviour of probability models. The real-life examples have all been typical random variables. A random variable (RV) is simply any quantity that varies according to some random process, and our first task is to choose an appropriate probability model to parallel the real situation, if we can. Sometimes this is easy-the result of the throw of a fair die calls for a very simple model-but some times it is impossible to produce a plausible probability model.
Sums and differences of random variables (RVs)
Authors: Cruickshank Steven 
Published: November 2023

Abstract
The die is an example of the uniform distribution which is almost as simple as a distribution can get. But if our RV is the sum of two throws of a die, what distribution do we get then? The range of outcomes is now 2, 3, … , 12, but is the distribution still uniform? Each throw of the die is independent and each possible combination-six for the first throw and six for the second-occur with equal probability; 36 possibilities in all.
Conditional probability and Bayes’ theorem
Authors: Cruickshank Steven 
Published: November 2023

Abstract
We have now encountered the idea of a conditional probability, where the test result is conditional on the presence or absence of a condition-here difficulty in intubation, D. Before we perform a test, there is a probability of D, p(D), which is dependent upon the extent of prior information. If the patient is unselected, then p(D) is that of the prevalence in the general population, 2%. If we already know that the patient has ankylosing spondylitis,
The normal distribution
Authors: Cruickshank Steven 
Published: November 2023

Abstract
It seems to be true that, however little students know about probability and statistics, they will be familiar with the essential features of the ‘bell-shaped’ normal distribution. The normal distribution made a short appearance as a model of measurement error when we were considering estimation of the SVP of a new anaesthetic agent (3.5.1). This model was essentially an empirical one, in that the pattern of measurement error had the same ‘shape’ as the normal.
Statistical inference
Authors: Cruickshank Steven 
Published: November 2023

Abstract
Two key concepts that we shall need repeatedly are those of population and sample. A population may be some circumscribed group-the number of children under eight years admitted to a particular ITU in in a particular year, for example-or some more abstract collection. In the anaphylactoid reaction example, the random variable was the observed number of severe reactions annually. The observed values of the RV form a sample from all the possible observations that we might make-the population. Although we can actually only make a limited number of observations, we view these observations as arising from some larger collection, the population. It is usually quite clear what the population comprises in any given problem.
Sample variance
Authors: Cruickshank Steven 
Published: November 2023

Abstract
The SVP example was quite easy to deal with because the manufacturer knew the precision of the measurement method, a-= 4 mmHg; he was attempting to determine the unknown mean of a normal distribution of known variance. If he had no information on the value of a-, then he could still make a point estimate ofμ from the sample mean x, but he could not quote a CI because he would need to know the precision a- to calculate the SEM (3.13.2). Such prior knowledge of the variability of the parent population is very unusual indeed in practical studies; it is far more common to have no information about either mean or variance.
Significance testing
Authors: Cruickshank Steven 
Published: November 2023

Abstract
Suppose that we are investigating the release of a plasma peptide after administration of an intravenous induction agent. We have a sample of ten patients and for each we have a pre-administration and a post-administration plasma peptide level. Thus we have a collection of ten data pairs. How can we decide whether there is evidence of release of the peptide by the agent? We shall see later one method-the paired t-test (3.16.3) but first let us look at the simulated data with a rough and ready method-the sign test. This demonstrates all of the important features of significance testing in a simple setting.
Categorical data
Authors: Cruickshank Steven 
Published: November 2023

Abstract
Suppose that we have a new intravenous anaesthetic agent Zapidate. This causes pain on injection in some patients and an investigation is conducted to examine the effect of the addition of local anaesthetic, ‘Wondercaine’, on the incidence of this. 261 patients are randomly allocated to one of two groups to receive Zapidate with or without addition of Wondercaine. We count the number of patients who experience pain on injection in each of the two groups. Suppose that the incidence of pain is lower in the Wondercaine group. How do we decide whether the effect of Wondercaine is significant?
Related variables: correlation
Authors: Cruickshank Steven 
Published: November 2023

Abstract
The Paco2 regression on duration of apnoea is an example in which it is clear that the response variable is dependent upon the predictor variable and not the other way round; we know that time is independent of Paco2 There are many circumstances in which variables are related but the predictor/response relation is less clear. For instance, we know that tall people tend to have larger feet than short people, so that knowledge of height enables us to predict shoe size better than if we have no information on height. The concept of correlation is based upon the ability to predict from one variable to another in a similar way to regression but where we may have no way of independently controlling a ‘predictor’ variable-the related variable is itself normally distributed.
Distribution-free methods
Authors: Cruickshank Steven 
Published: November 2023

Abstract
Imagine that we are conducting a study to compare the effectiveness of two analgesics in pain relief after minor surgery. Suppose that we have randomly allocated seven patients to two groups; three to receive drug A and four to dnig B. Pain relief can be measured by asking patients to use an analogue pain score. It is not obvious how results of individual pain scores might be distributed, so we will use a technique which does not make any assumptions about the distributional origin of the data. Since we have no postulated distribution, we shall not be able to estimate parameters, but we can decide whether there is evidence of a difference in the effectiveness of the two analgesics. Of course, with such pathetically small numbers, we could not reach any very firm conclusions, but we can more easily see how the test works.
Reference intakes, dietary goals and nutrition labelling of foods
Authors: Bender David A , Bender Arnold E 
Published: November 2023

Abstract
There is a 20-30 per cent range of individual variation around the mean requirement for most nutrients. For the planning of diets for populations, specific groups of the population or institutions, it is necessary to ensure that the intakes of nutrients provided are sufficient to ensure that no-one suffers deficiency or inadequacy. For any parameter that is statistically normally distributed, a range of ± 2SD around the mean includes 95 per cent of the values. Although there is little evidence, it is generally assumed that individual nutrient requirements are normally distributed around the mean-the only nutrient for which there is clear evidence that this is not so is iron, which shows a markedly skewed distribution of requirements (see section 24.2). Therefore, an appropriate level of intake for all nutrients, but not for energy, is considered to be 2 standard deviations above the mean requirement, as determined experimentally. Because energy intake in excess of requirements to meet expenditure leads to the development of obesity (see Chapter 11), appropriate levels of energy intake are considered to be the mean requirement, not a level 2 x SD above the mean.
Carbohydrates
Authors: Bender David A , Bender Arnold E 
Published: November 2023

Abstract
Carbohydrates provide some 35-45 per cent of the energy intake in most developed countries, with a desirable level of intake being 55 per cent of energy, to compensate for the desirable reduction in fat intake (see section 4.2); in less developed countries carbohydrate may provide as much as 75 per cent of energy intake. Average and desirable levels of carbohydrate intake are shown in Table 7.1, and major sources in the average diet in Table 7.2.
Alcohol and alcoholic beverages
Authors: Bender David A , Bender Arnold E 
Published: November 2023

Abstract
Alcoholic beverages, made by fermenting fruit juices, sugars and other fermentable carbohydrates with yeast to form alcohol, have a long history, and are widely consumed in most countries, except where religious observance prohibits their consumption. Moderate consumption of alcohol is associated with lower mortality from cardiovascular disease, but persistent heavy consumption is associated with physiological addiction-alcoholism. In addition to the addiction, there may be damage to the liver (cirrhosis), stomach (gastritis) and pancreas (pancreatitis), as well as behavioural changes and peripheral nerve damage. Both general malnutrition and more specifically deficiency of thiamin (see section 17.5.5), niacin (see section 19.5), and zinc (see section 25.26.2) are associated with alcoholism.
Vitamin E and selenium
Authors: Bender David A , Bender Arnold E 
Published: November 2023

Abstract
Unlike the other vitamins, vitamin E seems not to have a specific enzymic function; rather it is the major lipid-soluble, free radical-trapping antioxidant in membranes, and many of its functions can be met by synthetic antioxidants. However, some of the effects of vitamin E deficiency in experimental animals do not respond to synthetic antioxidants. The metabolic roles of vitamin E and the trace element selenium are closely related, and to a very great extent each can compensate for a deficiency of the other. The sulphur amino acids (methionine and cysteine) also have a vitamin Esparing effect.