Arthritis Australia

By O. Kurt. Roanoke College. 2018.

Because teeth consist largely of calcium and phosphate triamterene 75 mg low cost, the concentration of calcium and phosphate in saliva and plaque is thought to be important in determining the progression or regression of caries buy generic triamterene 75 mg. Although it may seem sensible to try to maximize the availability of calcium, phosphate, and fluoride in the environs of the tooth, in practice, fluoride is much the most important. Key Points Dental caries: • occurs in plaque-covered areas frequently exposed to dietary carbohydrates; • the initial lesion is subsurface before the thin surface layer collapses; • the initial or pre-cavitation lesion is reversible; • saliva plays an essential part in caries prevention; • if all plaque is removed from the surface the carious process stops. The dotted line represents a typical pH value below which enamel will dissolve (the critical pH). The body of the lesion shows marked radiolucency (loss of mineral) in contrast to sound enamel and the surface layer: ×70. One of the tasks of epidemiology is to record the level of disease and the variation between groups. A second task is to record changes in the levels of dental caries in populations over time, while a third task is to try to explain these variations. The United Kingdom has one of the best series of national statistics on dental caries. The dental health of adults and children has been recorded every 10 years, beginning with the Adult Dental Health Survey of 1968 (Table 6. They are national, using sound sampling methods to obtain representative samples of the populations. They include both clinical and sociological data, giving the interaction between knowledge, attitude, behaviour, and disease. The methods are well described and carefully standardized, resulting in meaningful longitudinal information. Data on children at the ages of 5, 12, and 14 are also available through the annual studies conducted under the auspices of the British Association for the Study of Community Dentistry. The ravages of dental caries were so severe in the past that the extent of disease in a population was measured by the proportion of the population with no natural teeth or edentulousness. A marked decrease in the per cent edentulous between 1968 and 1998 was recorded, especially in adults aged 35-54 years. For younger people, it is common to record the prevalence (the proportion of people affected), the severity (number of teeth affected per person) of dental caries and the percentage of carious teeth restored (Care Index). What is of concern is opinion that in the youngest age groups the improvement is not continuing, and indeed there are signs that caries experience is increasing in some areas. A decline in caries, first noticed during the 1970s, has been recorded in a large number of industrialized countries. The dental health of older children continued to improve in the 1980s but caries experience in primary teeth, measured at ages 5 or 6 years, had stayed fairly constant. The Nordic countries used to have very high caries experience and the drastic improvement in all five Nordic countries can be seen in Fig. Caries experience in Australian children has been well recorded indicating a dramatic improvement in dental health (Fig. Reports from North America indicate that caries prevalence and severity in the permanent dentition have continued to decline since 1982 in Canada and the United States, but that caries experience in the primary dentition may have stabilized since about 1986-7. While dental surveys of schoolchildren have been quite common, there is much less information on the dental health of preschool children mainly because access to them is more difficult (Table 6. The prevalence and severity of dental caries in British preschool children was reviewed by Holt (1990), and in preschool children around the world by Holm (1990). In most European countries, North America, and Australia, caries experience has declined in parallel with the increasing use of fluoride toothpastes, although this decline appears to have stopped in the United Kingdom. Caries experience of preschool children in South-East Asia, Central America, and parts of Africa is high and there are discernible trends of increasing prevalence in parallel with the rise in availability of sugar-containing snacks and drinks. While the state of the permanent dentition in children has improved dramatically in many countries, caries in primary teeth is still a considerable problem in preschool and school-aged children. In industrialized countries, caries experience is highest in the more deprived groups of society and often in ethnic minority groups. In developing countries, the reverse social trend is observed, with the well-off, urban children having the most caries experience. In adults, provision of dental services and patient preference for treatments can have a major effect on the state of the dentition, in addition to the aetiological and preventive roles of sugar, fermentable carbohydrates, and fluoride. Key Points Dental caries • Epidemiology indicates the size of the problem of caries and changes over time. Below the waterline lie the lesions which need the use of some form of additional aid to be identified. This can range from radiographs in the clinical situation to histopathology in the in vitro setting. The identification of caries depends on a systematic examination of clean dry teeth. The basic equipment consists of adequate lighting, compressed air for drying, dental mirror, and blunt or ball ended probe.

Verapam il should only be used w ith caution as it m ay w orsen the outflow obstruction (through the increased vasodilatation and consequent ventricular em ptying w ith contraction) buy 75 mg triamterene with visa. Supraventricular arrhythm ias including atrial fibrillation m ay be controlled w ith beta blockers generic triamterene 75mg free shipping, verapam il or am iodarone. Surgical septal m yectom y is long established and can be com bined w ith m itral valve replacem ent in patients w ith associated significant m itral regurgitation. W hen patients present w ith progressive ventricular dilatation and reduced systolic function, cardiac transplantation m ay need to be considered. O ral am iodarone and/or an im plantable cardiac defibrillator are the available options. Percutaneous translum inal septal m yocardial ablation in hypertrophic obstructive cardiom yopathy: acute results and 3-m onth follow -up in 25 patients. Niall G Mahon and W McKenna There are broadly tw o categories of indications for perm anent pace- m aker insertion in patients w ith hypertrophic cardiom yopathy: • Standard indications for pacing w hich apply to any patient. Indications for the use of dual cham ber pacing w ith a short program m ed atrioventricular delay for this purpose rem ain to be determ ined. Gradient reduction is thought to com e about through a variety of effects on septal and papillary m uscle m otion and contractility. In general outflow gradients can be reduced by approxim ately 50% but the translation of this benefit into clinical im provem ent is variable and unpredictable. A considerable placebo effect of the procedure has been observed in at least tw o random ised studies. The role of pacing in young patients is unclear and m ethods of identifying patients likely to benefit from the procedure have not been established. Dual cham ber pacing for hypertrophic cardiom yopathy: a random ised double blind crossover trial. Niall G Mahon and W McKenna Diagnostic criteria for the diagnosis of hypertrophic cardio- m yopathy in first degree relatives have been proposed as show n in Table 51. Relatives are considered affected in the presence of one m ajor criterion or tw o m inor echocardiographic criteria or one m inor echocardiographic plus tw o m inor electro- cardiographic criteria. These criteria do not apply w hen other potential causes such as athletic training, system ic arterial hyper- tension or obesity are present. Young children w ith no evidence of disease should be re-evaluated every 5 years until their teens and then annually until aged 21. Diagnosis in a child under 10 years requires a body surface area corrected left ventricular w all thickness of >10m m. Affected relatives should additionally undergo risk stratification, w hich includes 48 hour Holter m onitoring and exercise testing, looking especially for ventricular arrhythm ias and abnorm al blood pressure responses respectively. Niall G Mahon and W McKenna A protocol for the investigation of dilated cardiom yopathy should aim to confirm the diagnosis, rule out treatable causes, prevent potential com plications and determ ine prognosis. Cardiac dim ensions and systolic function are also of prognostic value, w ith an approxim ately 2-fold increase in relative risk of m ortality for every 10% decline in ejection fraction. Tw elve-lead electrocardiography and Holter m onitoring for arrhythm ias should be perform ed. O ccasionally a diagnosis of incessant tachycardia as a cause of the cardio- m yopathy m ay be m ade. Further investigation (such as for sarcoid or am yloid) should be guided by history and exam ination. O ther tests m ay also be perform ed, but are not indicated in every case: 1 Coronary angiography should be perform ed in patients over the age of 40 years, or w ho have risk factors or sym ptom s or signs suggestive of coronary disease. W hat is, how ever, clear is that a tissue histological diagnosis provides im portant prognostic inform ation w hich m ay (as in the case of sarcoidosis) have an im pact on treatm ent. In research centres, biopsy specim ens m ay be analysed by im m unohistochem ical and m olecular biological techniques to determ ine the presence or absence of low grade inflam m ation and viral persistence. Frequency of follow up w ill depend on the severity of involvem ent at initial presentation. The course of the disease at early follow up is a useful indicator of long term prognosis w ith im provem ent or deterioration occurring in m ost cases w ithin six m onths to one year of diagnosis. The possibility that the patient’s cardiom yopathy m ay be fam ilial should be explored by taking a detailed fam ily history, but incom plete and age-related penetrance m ake fam ily screening problem atic. The decision to evaluate (usually first degree) relatives should be individualised, based on the extent of disease w ithin a fam ily, the levels of anxiety am ong patients and relatives, the presence of suggestive sym ptom s and the extent of local experience in the evaluation of dilated cardiom yopathy. Predictive value of abnorm al signal-averaged electrocardiogram s in patients w ith non- ischem ic cardiom yopathy. Com parison of tim e dom ain and spectral turbulence analysis of the signal-averaged electrocardiogram for the prediction of prognosis in idiopathic dilated cardiom yopathy. Underlying causes and long- term survival in patients w ith initially unexplained cardiom yopathy. The survival advantages are consistent (m ortality reduction of about 20% ) and far outw eigh the relatively sm all risk of serious side effects. Calculations suggest that a reduction in m ortality could be achieved w ithout side effects after treating only 24 patients.

Using the Paste command for the above recode provides the following documentation buy triamterene 75 mg on line. After recoding discount triamterene 75 mg otc, the value labels for the three new categories of place2 that have been created can be added in the Variable View window. In this case, place of birth needs to be defined as 1 = Local, 2 = Regional and 3 = Overseas. This can be added by clicking on the Values cell and then double clicking on the grey domino box on the right of the cell to add the value labels. Similarly, gender which is also a string variable can be recoded into a numeric variable (gender2) with Male = 1 and Female = 2. After recoding variables, it is important to check that the number of decimal places is correct. Using the Dialog Recall button to obtain Frequencies for place 2, which is labelled ‘Place of birth recoded’, the following output is produced. Frequencies Place of Birth Recoded Frequency Per cent Valid per cent Cumulative per cent Valid Local 90 63. When the data are recoded as numeric, the nine babies who have missing data for birthplace are correctly omitted from the valid and cumulative percentages. By using the command Edit → Options → General you can select whether variables will be displayed by their variable names or 20 Chapter 1 their labels in the dialog command boxes. There is also an option to select whether variables are presented in alphabetical order, in the order they are entered in the file or in measurement level. Under the command Edit → Options → Output, there are options to select whether the variable and variable names will be displayed as labels, values or both on the output. The format of the frequencies table obtained previously can easily be changed by double clicking on the table and using the com- mands Format → TableLooks. To obtain the output in the format below, which is a classical academic format with no vertical lines and minimal horizontal lines that is used by many journals, highlight Academic under TableLooks. The column widths, font and other features can also be changed using the commands Format → Table Properties. By click- ing on the table and using the commands Edit → Copy, or by clicking on the table and right clicking the mouse and selecting ‘Copy’, the table can be copied and pasted into a word file. Place of birth (recoded) Frequency Per cent Valid per cent Cumulative per cent Valid Local 90 63. A data file can also be exported to Excel using the File → Save as → Save as type: Excel commands. By using the commands Help → Topics → Index, the index of help topics appears in alphabetical order. There is also another level of help that explains the meaning of the statistics shown in the output. For example, help can be obtained for the above frequencies table by doubling clicking on the left-hand mouse button to outline the table with a hatched border and then single clicking on the right-hand mouse button on any of the statistics labels. Clicking on Cumulative Percent opens up a dialog box providing the explanation that this is ‘The percentage of cases with non-missing data that have values less than or equal to a particular value’. When reporting data, it is important not to imply more precision than actually exists, for example, by using too many decimal places. Results should be reported with the same number of decimal places as the measurement, and summary statistics should have no more than one extra decimal place. A summary of the rules for reporting numbers and summary statistics is shown in Table 1. Results from studies in which out- liers are treated inappropriately, in which the quality of the data is poor or in which an incorrect statistical test has been used are likely to be biased and to lack scien- tific merit. Try and avoid starting a sentence with a number Numbers that represent statistical or Raw scores were multiplied by 3 and then mathematical functions should be expressed in converted to standard scores numbers In a sentence, numbers below 10 that are listed In the sample, 15 boys and 4 girls had diabetes with numbers 10 and above should be written as a number Use a zero before the decimal point when The P value was 0. Practical and statistical issues in missing data for longitudinal patient reported outcomes. If a variable has significant skewness or kurtosis or has univari- ate outliers, or any combination of these, it will not be normally distributed, that is, the distribution histogram will not conform to a bell shape. Information about each of these characteristics determines whether parametric or non-parametric tests need to be used and ensures that the results of the statistical analyses can be accurately explained and interpreted. A description of the characteristics of the sample also allows other researchers to judge the generalizability of the results. A typical pathway for beginning the statistical analysis of continuous data variables is shown in Box 2. Parametric tests assume that the continuous variable being analysed has a normal distribution in the population.

The lines of people are packed so tightly together that triamterene 75 mg on-line, from the air buy generic triamterene 75 mg, you only see the tops of many heads in a “sea of humanity. From this perspective, the height of the curve above any score reflects the number of people standing in line at that score. The height of the curve above any score reflects the number of people standing in line at f that score. Therefore, any portion of the parking lot— any portion of the space under the curve—corresponds to that portion of the sample. Now turn this around: If 50% of the participants obtained scores below 30, then the scores below 30 occurred 50% of the time. This logic is so simple it almost sounds tricky: if you have one-half of the parking lot, then you have one-half of the participants and thus one-half of the scores, so those scores occur. Or, if you have 25% of the parking lot, then you have 25% of the participants and 25% of the scores, so those scores occur. This is how we describe what we have done using statistical terminology: The total space occupied by the everyone in the parking lot is called the total area under the nor- mal curve. We identify some particular scores and determine the area of the correspon- ding portion of the polygon above those scores. We then compare the area of this portion to the total area to determine the proportion of the total area under the curve that we have selected. Then, as we’ve seen, The proportion of the total area under the normal curve that is occupied by a group of scores corresponds to the combined relative frequency of those scores. Of course, statisticians don’t fly around in helicopters, eyeballing parking lots, so here’s a different example: Say that by using a ruler and protractor, we determine that in Figure 3. Say that the area under the curve between the scores of 30 and 35 covers 2 square inches. Therefore, the scores between 30 and 35 occupy 2 out of the 6 square inches created by all scores, so these scores constitute 2>6, or. We could obtain this answer by using the formula for relative frequency if, using N and each score’s f, we computed the rel. However, the advantage of using the area under the curve is that we can get the answer without knowing N or the simple frequencies of these scores. Scores Computing Cumulative Frequency and Percentile 51 In fact, whatever the variable might be, whatever the N might be, and whatever the ac- tual frequency of each score is, we know that the area these scores occupy is 33% of the total area, and that’s all we need to know to determine their relative frequency. This is especially useful because, as you’ll see in Chapter 6, statisticians have created a system for easily finding the area under any part of the normal curve. Therefore, we can easily determine the relative frequency for scores in any part of a normal distribu- tion. If a score occurs 23% of the time, its relative fre- ■ The area under the normal curve corresponds to quency is. They make up of the 15% of people in the parking lot are standing at these area under the normal curve. For example, it may be most informative to know that 30 people scored above 80 or that 60 people scored below 80. When we seek such information, the convention in statistics is to count the number of scores below the score, computing either cumulative frequency or percentile. To compute a score’s cumulative frequency, we fies the scores, the center col- add the simple frequencies for all scores below the score to the frequency for the score, umn contains the simple to get the frequency of scores at or below the score. We add this f to the previous cf for 10, so the cf for 11 is 3 (three people scored at 11 or below 11). Next, no one Score f cf scored at 12, but three people scored below 12, so the cf for 12 is also 3. And so on, each time adding the frequency for a score to the cumulative frequency for the score 17 1 20 16 2 19 immediately below it. Computing Percentiles We’ve seen that the proportion of time a score occurs provides a frame of reference that is easier to interpret than the number of times a score occurs. Therefore, our final procedure is to transform cumulative frequency into a percent of the total. A score’s percentile is the percent of all scores in the data that are at or below the score. Thus, for example, if the score of 80 is at the 75th percentile, this means that 75% of the sample scored at or below 80. Score f cf Percentile This says to first divide the score’s cf by N, which transforms the cf into a proportion of the total sample. Then we multiply this times 100, which converts it into a percent of 17 1 20 100 the total. Thus, if a score has a cf of 5 and N is 10, then 15>10211002 5 50, so the score 16 2 19 95 15 4 17 85 is at the 50th percentile.