A study of red and white light on the chart table for navigation at sea.
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Authors often find it difficult to develop effective tables and charts for their research manuscripts. Tables often include too many columns or rows, have too much data, and use too many lines. Charts often have poor design, too much content, numbers carried out too far, and other problems. This author describes how to avoid these problems to develop quality tables and charts to enhance your research manuscript.
OBJECTIVE: To create reliable reference ranges and calculate Z scores for fetal abdomen and femur ultrasound biometry using a large sample size which is evenly distributed from 12 to 42 weeks of pregnancy. DESIGN: A prospective, cross-sectional study. SETTING: Obstetric clinics (outpatient and delivery units) at the University Hospital of Zurich. SAMPLE: The study data were obtained from 6557 pregnant women. METHODS: Only the first ultrasound examination between 12 and 42 weeks of each fetus with certainly established gestational age was used for analysis. No exclusions were made on the grounds of small-for-date birthweight, prematurity or other events several weeks after the examination. Separate regression models were fitted to estimate the mean and standard deviation at each gestational age for each parameter. RESULTS: A total of 5807 mean abdominal diameters and abdominal circumferences were derived from fetal transverse and anterio-posterior fetal abdominal diameter measurements. Fetal femur length was measured in 5860 instances. The charts, tables and regression formulae of the biometrical measurements are presented. A comparison of our charts with others showed no significant difference. Only Merz's centiles for abdominal biometry were lower and for femur length higher than ours. An application to calculate Z scores was developed using Excel (Microsoft Corporation, USA); the macros are presented in detail in the Figure 6 footnote. CONCLUSIONS: We have presented centile charts, tables and formulae for fetal abdominal diameter and circumference and femur length derived from a large and minimally selected sample size in a carefully designed cross-sectional study. Complete tables and regression formulae to calculate reference ranges and Z scores are presented to use in computer-aided evaluation of fetal ultrasound biometry.
OBJECTIVE: To create reliable reference ranges and calculate Z scores for fetal head ultrasound biometry using a large sample size which is evenly distributed from 12 to 42 weeks of pregnancy. DESIGN: A prospective, cross-sectional study. SETTING: Obstetric clinics (outpatient and delivery units) at the University Hospital of Zurich. SAMPLE: The study data were obtained from 6557 pregnant women. METHODS: Only the first ultrasound examination between 12 and 42 weeks of each fetus with exactly established gestational age was used for analysis. No exclusions were made on the grounds of small-for-date birthweight, prematurity or other events several weeks after the examination. Separate regression models were fitted to estimate the mean and standard deviation at each gestational age for each parameter. RESULTS: A total of 6217 fetal head biparietal diameters and 5510 occipito-frontal diameters were measured. Both head circumference and cephalic index were derived in 5462 cases where both biparietal diameter and occipito-frontal diameter could be measured on the same fetus. The centile charts, tables and regression formulae for biparietal and occipito-frontal diameters, head circumference and cephalic index are presented. An application to calculate Z scores was developed using Excel (Microsoft Corporation, USA) and macros are presented in detail in the Figure 8 footnote. The comparison of our charts with those of the two most recent studies revealed almost no differences in biparietal diameter centiles. In one publication, occipito-frontal diameter charts, and in another, head circumference charts were different from the current study. CONCLUSIONS: We have presented centile charts, tables and regression formulae for fetal head ultrasound biometry derived from a large and minimally selected sample size in a carefully designed cross-sectional study. Complete tables and regression formulae to calculate reference ranges and Z scores are presented for use in computer-aided evaluation of fetal ultrasound biometry.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
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Explore the source record for details and available documents.
For the first time in Italy, the results of a multicentre study of the Study Group into Juvenile Hypertension of the Italian Society of Paediatrics in 16.772 subjects from 0 to 18 years, are presented. Percentile charts (tables) of juvenile blood pressure (BP) levels according respectively to age and height of the subjects divided by sex, have been elaborated. Also pressure curves have been calculated and drawn that are based on standard deviations (DS). Normal levels are between + and -2DS. The relationship of BP levels with age permits the comparison with the Task force Tables, whilst the relationship with height permits comparison with the European data.
OBJECTIVES: Health service managers and other decision-makers are required to act on the basis of data. Little attention has been paid to the effects of data presentation on the decisions taken. This study uses a randomized controlled trial design to investigate the effects of two forms of data presentation--league tables and control charts--on health service decision-makers. METHODS: Directors of public health in 122 health authorities in the UK were mailed three case studies and a questionnaire. The case studies showed data on variations in mortality by health service provider. The questionnaire asked them to indicate whether they would take action as a result of the data and to identify the health service providers on whom they would take action. Participants were randomly allocated to receive the same data in the form of ranked histograms (league tables) or control charts. MAIN OUTCOME MEASURE: The percentage of participants who would take action on health service providers. RESULTS: Fifty-seven questionnaires were returned. For each case study, respondents receiving data as league tables stated they would take action on significantly more health service providers than those receiving data as control charts: for the first case study, the percentages were 3.3% versus 1.8% (P < 0.001) for league tables and control charts, respectively; for the second case study, 15.9% versus 6.7% (P = 0.029), respectively; and for the third, 5.9% versus 0.7% (P = 0.002), respectively. Respondents receiving data as league tables were significantly more likely to request further information on case mix. CONCLUSIONS: Compared with league tables, health service decision-makers identify fewer outliers for further action when performance data are presented as control charts. They also reduce the tendency to request further information. Using control charts rather than league tables for the routine presentation of comparative data would reduce over-investigation of unusual performance.
A collective, analytic review was undertaken of all available published scientific papers that reported data about risks, hazards, adverse effects, or complications from augmentation of blood gas exchange by means of intensive closed system positive pressure mechanical ventilation. On the basis of the data collected, the adverse effects of intensive positive pressure mechanical ventilation were classified into the following groups: oxygen toxicity; adverse effects from excessive ventilatory pressures, volumes, and flow rates; adverse effects from tracheal intubation; dangers from adjuvant drugs; stress-related sequelae; altered enzyme and hormone systems; nutritional problems; and psychologic trauma. A bibliography pertaining to each group of adverse effects has been prepared. In addition, the reported incidence of adverse effects resulting from intensive mechanical ventilation in patients in clinical intensive care is shown. Clinical and laboratory observations of patients who receive intensive positive pressure mechanical ventilation in respiratory intensive care units have yielded some data, and findings from experimental studies in normal volunteers and laboratory animals have also been collected and reviewed. Tables, charts, and graphs that summarize the pertinent findings are presented and discussed. The following conclusions are drawn from critical evaluation of the collected data: (1) Closed system positive pressure mechanical ventilation applied at mild to moderate levels of intensity is a safe and effective method for augmenting deficient blood gas exchange in most patients who are in acute respiratory failure. (2) On the other hand, intensive levels of mechanical ventilator support or inappropriate methods of applying mechanical ventilation may be accompanied by a variety of risks, hazards, adverse effects, and complications that may further injure the failing lungs or may add significantly to the morbidity and mortality rates of patients in whom it is applied. (3) Because of the unfavorable risk/benefit ratio of intensive positive pressure mechanical ventilation, physicians should consider the use of alternative methods that are now available for augmenting blood gas exchange in patients in acute respiratory failure who are not adequately treated by safe (mild to moderate) levels of positive pressure mechanical ventilation instead of electing to increase the intensity of positive pressure mechanical ventilation to more dangerous (intensive) levels.
OBJECTIVES: The objectives of this prospective study were (i) to establish new reference values of peak systolic blood flow velocity measurement in the fetal middle cerebral artery (MCA-PSV) following validated methodological guidelines and (ii) to develop a method to calculate Z-scores of MCA-PSV. PATIENTS AND METHODS: Cross-sectional data were obtained from 331 pregnant women between 19 and 40 weeks' gestation. Reference ranges for MCA-PSV were constructed and for each measurement linear regression models were fitted separately to the mean and standard deviations (SD) as a function of gestational age. An application to calculate Z-scores was developed. A comparison was made between the reference ranges produced in our study and those of a previous one. RESULTS: A new chart, table of centiles and regression equations of MCA-PSV are presented. Comparison of our reference ranges with ones produced in a previous study showed similar 5th centile values. However, the values for the 50th and 95th centiles between 19 and 28 gestational weeks were lower in our study. CONCLUSIONS: We have constructed reference ranges for MCA-PSV which, because they are derived from a larger number of examinations in the 15-20-week period and because the methodological flaws of the previously published study have been eliminated, we consider to be more accurate and therefore more useful for clinical practice.
The purpose of the Centre for Operational Research in Public Health (CORPH) is to optimize the accessibility to health information, thus making it possible to measure and follow up the health status of the Belgian population. The Standardized Procedures for Mortality Analysis (SPMA) software was developed in order to facilitate the use of vital statistics for health policy-makers and scientific researchers. Nowadays, SPMA is available on the Internet, because accessibility to health information is crucial. SPMA serves via a system of menus as the interface between databases (population, birth, and mortality) on one hand and statistical procedures on the other hand. Users can choose the parameters such as year, cause of death, geographical level, and statistical indicator, and so dynamic reports are produced 'on demand'. These procedures are available for the following modules: overall mortality, specific cause mortality, and perinatal statistics. Analysis can be carried out for one specific year or for a period over time. Pre-defined procedures accessible through menus make SPMA user-friendly, as it can be used without any preliminary knowledge of the statistical package. Tables, charts, or maps display the results. Users need only an Internet browser to access the application.
The calculations required to evaluate the thermal environment can be tedious and time consuming. To reduce this effort to a minimum, a computer program is presented that requires only five basic measurements to calculate and print out a complete evaluation of the thermal environment at a specific location. These are the dry bulb, natural wet bulb, psychrometric wet bulb and black globe temperatures, and the air velocity. Any reference to charts, tables and nomographs is unnecessary, since all other quantities are contained within, or computed by, the program.
Graphical representation of changes in epidemiologic or clinical parameters over time is difficult when a large amount of data is involved. The traditional methods either cannot incorporate all necessary information (bar graphs, pie charts, tables) or are unable to depict information on more than a limited number of individuals (scattergrams). We have designed an effective way of visual presentation of the changes a variable demonstrates over time. The percentage scattergram provides accurate and complete depiction of any number of data points, allowing comprehensive and rapid analysis.