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At least 73 records · Page 4Linked to original sources
PubMed1989

[Cause od death statistics and death certificate documentation. 1. Historical development of cause of death statistics of fetal death, infants and children and current regulations in the GDR].

After having described the beginnings of documentation and statistics of causes of death of newborns and children the development of this branch of medical statistics in the GDR and the introduction of a special death certificate in 1961 is dealt with. To help obstetricians, perinatologists and pediatrists to tackle the problem of documentation of the causes of death of stillborns and newborns the 9th revision of ICD, the nowadays valid death certificate and special rules of signing are explained to avoid mistakes, which are often met with in the daily practice.

Cause of Death↗
PubMed1995

Conventional statistics and useful statistics.

Differences between conventional statistical methods and more useful, modern methods are demonstrated using a statistical analysis of data from therapeutic research in rheumatology. The conventional methods, t-test and graphs of mean values and the boxplot, detect almost no differences between treatment groups. A more recent procedure for analysing group differences is the Wilcoxon-Mann-Whitney test. The associated graphs are based on the cumulative distribution function of the two treatment groups and the synthetic Receiver Operating Characteristic (ROC). Special differences, namely baseline dependencies, can be visualized in this way.

Adjuvants, Immunologic↗
PubMed1999

[Clinical statistics at the urological clinic of Sanjukai Hospital--statistics on new outpatients over the last five years].

We herein report the clinical statistics on new outpatients over five years from 1994 at our hospital. The average number of new outpatients per year was 8,534.4 (8,366-8,658) and there was only a slight variation in the number over the last five years. The male to female ratio was 1.61:1. Twenty-one percent of the outpatients were referred to us by other sources. The representative operations on outpatients were circumcision, vasectomy, resection of condylomas and resection of caruncles. A statistical study was made on new outpatients according to the international classification of disease. There were 197.0 (2.3%) malignant urogenital tumors per year. There was a tendency for sexually transmitted diseases to increase over the last five years. In males, the major diseases were upper urinary tract stones (23-27%), benign prostatic hypertrophy (19-26%) and prostatitis (15-24%). In females, they were cystitis (57-59%), upper urinary tract stones (17-18%) and neurogenic bladder (3-4%). We conclude that our hospital plays a major role as a private urological hospital.

Adult↗
PubMed1998

International comparative analysis of injury mortality. Findings from the ICE on injury statistics. International Collaborative Effort on Injury Statistics.

OBJECTIVE: This report investigates international differences in injury mortality rates among 11 of the countries participating in the International Collaborative Effort on Injury Statistics. METHODS: The cause, intent, and age-specific injury mortality rates are calculated and presented from Australia, Canada, Denmark, England & Wales, France, Israel, New Zealand, The Netherlands, Norway, Scotland, and the United States. Data are presented by cause (or mechanism) and intent (or manner of death) according to the matrix framework for presenting injury mortality statistics published in August 1997. The benefits of this matrix approach to investigating injury mortality are explained with numerous examples. RESULTS: Injury death rates are higher in France and Denmark and lower in England & Wales, Israel, and The Netherlands than elsewhere. New Zealand, the United States, and Norway had similar average annual injury death rates of 56-57 per 100,000 population. As an example of the benefit of presenting data in the matrix framework, the total poisoning death rate in Denmark for all categories of intent (13 per 100,000) is about twice the rate in the United States. Unintentional poisoning death rates, however, are similar in the United States and Denmark (about 4 per 100,000) and are higher than elsewhere. However, the suicide poisoning death rate in Denmark is 3 times the rate in the United States. CONCLUSION: Using these results, the ICE on Injury will be investigating death registration practices in each of the countries to better understand international variation in injury mortality due to reporting or registration procedures.

Accidents↗
PubMed1998

Statistical Inference (Part 3): Statistical Hypothesis Testing and Confidence Interval Estimation.

An association between an independent and a dependent variable found in a study may have several explanations, including chance (i.e., random error). This article presents two approaches to assess the role played by chance in an association: confidence interval estimation and statistical hypothesis testing. Statistical hypothesis testing estimates the probability (i.e., the P value) of getting a difference as large or larger than the one observed in a specific study assuming the absence of association. Confidence intervals are estimates of the range of values that are expected to include the actual parameter with a certain probability, or confidence level (often 0.95 or 95%).

Journal Article↗
PubMed1995

[Clinical statistics at the urological clinic of Sanjukai Hospital--statistics on new outpatients during the last five years].

We report the clinical statistics of new outpatients for five years since 1989 at our hospital. The average total number of new outpatients in a year was 8309.8 (8122-8691) and new outpatients tended to show little change. The male to female ratio was 1.57:1, and 24.3% of the outpatients were referred to us by others sources. The representative operations on outpatients were circumcision, vasectomy, resection of condyloma and resection of caruncle. A statistical study was made on new outpatients according to the international classification of disease. There were 140.6 (1.97%) malignant urogenital tumors per year. Sexually transmitted diseases showed a tendency to increase for the last five years. In males the major disease was upper urinary tract stone (21-24%), prostatistis (21-24%) and benign prostatic hypertrophy (17-20%) and in females they were cystitis (58-61%), upper urinary tract stone (15-17%) and pyelonephritis (3-4%). We conclude that our hospital plays a major role as a private urological hospital.

Female↗
PubMed1996

The statistical analysis of kappa statistics in multiple samples.

Methods are presented for assessing and comparing the results of k > or = 2 independent samples of measured agreement or concordance, where in each sample a given member of a pair of observations is classified according to the presence or absence of a binary trait. Examples include the assessment of interobserver agreement across different groups of patients in a clinical study, investigations of sibling concordance across different genetic groups, and meta-analyses of observer agreement across different studies. The methodology described is based on application of goodness-of-fit theory to testing hypotheses concerning kappa statistics. Partitioning methods allow a variety of hypotheses to be tested, including an assessment of the degree of agreement within each sample, a testing procedure based on the pooled data, and a test of heterogeneity that may be used to assess the validity of pooling across samples. Three examples are given.

Humans↗
PubMed1990

Statistical significance and statistical power in hypothesis testing.

Experimental design requires estimation of the sample size required to produce a meaningful conclusion. Often, experimental results are performed with sample sizes which are inappropriate to adequately support the conclusions made. In this paper, two factors which are involved in sample size estimation are detailed--namely type I (alpha) and type II (beta) error. Type I error can be considered a "false positive" result while type II error can be considered a "false negative" result. Obviously, both types of error should be avoided. The choice of values for alpha and beta is based on an investigator's understanding of the experimental system, not on arbitrary statistical rules. Examples relating to the choice of alpha and beta are presented, along with a series of suggestions for use in experimental design.

Research Design↗
PubMed1998

Statistical methods in epidemiology: a comparison of statistical methods to analyze dose-response and trend analysis in epidemiologic studies.

Evaluation of various statistical methods to describe accurately associations between exposures and disease are constantly being explored. Spline regression has been suggested as an alternative to using categorized variables in studies of disease etiology, as it uses all data points to estimate the shape of the association between a given exposure and disease outcome. It has been proposed that this method is especially beneficial when associations are concentrated in a small range of the overall distribution of the exposure. In this study, we use data from a large case-control study of colon cancer to evaluate associations obtained from logistic regression models that use spline regression for main exposure and confounder effects with those that use categorized variables for main exposure. Our results show that for variables for which the association appears to be linear, such as body size and dietary intake of calcium, fiber, and cholesterol, associations are similar when estimates are generated from spline or categorized variable models. For other variables, such as total energy intake, for which associations appear to be strongest in the upper end of the distribution, estimates of association appear to be conservative when using categorized variables. The data also suggest that selection of cut points for the categorized variables may have an impact on the associations observed. Spline regression appears to be useful to estimate the shape of the association between a given exposure and disease and may provide guidance as to the appropriateness of using categorized variables. The risk estimates from spline regression appear to be similar to those from traditional categorical methods. When effects are large or rapidly changing, spline models may more appropriately describe the association.

Adult↗
PubMed2003

Statistical approaches for assessing the relative validity of a food-frequency questionnaire: use of correlation coefficients and the kappa statistic.

OBJECTIVE: To compare different statistical methods for assessing the relative validity of a self-administered, 150-item, semi-quantitative food-frequency questionnaire (FFQ) with 4-day weighed diet records (WR). DESIGN: Subjects completed the Scottish Collaborative Group FFQ and carried out a 4-day WR. Relative agreement between the FFQ and WR for energy-adjusted nutrient intakes was assessed by Pearson and Spearman rank correlation coefficients, the percentages of subjects classified into the same and opposite thirds of intake, and Cohen's weighted kappa. SUBJECTS: Forty-one men, mean age 36 (range 21-56) years, and 40 women, mean age 33 (range 19-58) years, recruited from different locations in Aberdeen, Scotland. RESULTS: Spearman correlation coefficients tended to be lower than Pearson correlation coefficients, and were above 0.5 for 10 of the 27 nutrients in men and 17 of the 27 nutrients in women. For nutrients with Spearman correlation coefficients above 0.5, the percentage of subjects correctly classified into thirds ranged from 39 to 78%, and weighted kappa values ranged from 0.23 to 0.66. CONCLUSIONS: Both Spearman correlation coefficients and weighted kappa values are useful in assessing the relative validity of estimates of nutrient intake by FFQs. Spearman correlation coefficients above 0.5, more than 50% of subjects correctly classified and less than 10% of subjects grossly misclassified into thirds, and weighted kappa values above 0.4 are recommended for nutrients of interest in epidemiological studies.

Adult↗
PubMed2003

Advanced statistics: applying statistical process control techniques to emergency medicine: a primer for providers.

Emergency medicine faces unique challenges in the effort to improve efficiency and effectiveness. Increased patient volumes, decreased emergency department (ED) supply, and an increased emphasis on the ED as a diagnostic center have contributed to poor customer satisfaction and process failures such as diversion/bypass. Statistical process control (SPC) techniques developed in industry offer an empirically based means to understand our work processes and manage by fact. Emphasizing that meaningful quality improvement can occur only when it is exercised by "front-line" providers, this primer presents robust yet accessible SPC concepts and techniques for use in today's ED.

Emergency Medicine↗
PubMed1983

Statistics for diagnostic procedures. II. The significance of "no significance": what a negative statistical test really means.

Statistical tests are often used to compare two or more groups. When the tests show "no significant difference," many authors/readers conclude that this means that the groups are identical. Often this outcome is merely the result of inadequate sample size. The adequacy of sample size depends on well established mathematical principles, not on the investigator's intuition. The real meaning of "no significant difference" is discussed.

Diagnosis↗
PubMed1985

[Clinical statistics of the Urological Clinic of Higashi Sapporo Sanjukai Hospital. IV. Clinical statistics on patients admitted from Nov. 1, 1978 to Dec. 31, 1983].

A clinical statistic survey was carried out on the patients admitted, diseases and operations experienced at our urological clinic during 1978-1983. The total number of inpatients was 4,070. (The male to female ratio was 2.93:1) Major diseases of the inpatients were urolithiasis (982 cases, 24.1%), and BPH (923 cases, 22.7%). Among the operations, TUR-P (32.7%), TUR-BT (10.4%) and ureterolithotomy (7.7%) were predominant.

Adolescent↗
PubMedDate not supplied

Re-examination of the ED01 study. Review of statistics: the need for realistic statistical models for risk assessment.

The statistical analyses of the ED01 study leave us with the following conclusions: 1) To be realistic, risk assessment using chronic animal studies should be based on time-to-response data and models. 2) Simple standards such as a virtual safe dose and simple models such as the one-hit model or linear extrapolation seem ill-suited as scientific means for risk assessment for such extensive data sets as the ED01 study. 3) The development of new methods for analysis, modeling and risk assessment should be encouraged if future decisions are to be realistically based on chronic animal studies.

2-Acetylaminofluorene↗
PubMed1996

[Examples of pitfalls in statistical analysis--1. Summarizing your data before statistical analysis].

When conducting studies, it is important to summarize the gathered data before beginning calculations for statistical analysis. If the methods used to summarize the data are inadequate for purposes of the analysis you want to perform, many misleading or unreasonable discussions that are normally avoidable arise. If there is any uncertainty in the way data are handled, for example, confusion as to whether comparison of mean (parametric analysis) or comparison of median (nonparametric analysis) is used, or whether the data are paired or unpaired, it is impossible to make good charts that show us the features of the data at a glance. In this article, I will address several frequently asked questions about summarizing data, and discuss making suitable charts by presenting a typical example.

Data Collection↗