OBJECTIVETo explore several numerical methods of ordinal variable in one-way ordinal contingency table and their interrelationship, and to compare corresponding statistical analysis methods such as Ridit analysis and rank sum test.

METHODSFormula deduction was based on five simplified grading approaches including rank_r(i), ridit_r(i), ridit_r(ci), ridit_r(mi), and table scores. Practical data set was verified by SAS8.2 in clinical practice (to test the effect of Shiwei solution in treatment for chronic tracheitis).

RESULTSBecause of the linear relationship of rank_r(i) = N ridit_r(i) + 1/2 = N ridit_r(ci) = (N + 1) ridit_r(mi), the exact chi2 values in Ridit analysis based on ridit_r(i), ridit_r(ci), and ridit_r(mi), were completely the same, and they were equivalent to the Kruskal-Wallis H test. Traditional Ridit analysis was based on ridit_r(i), and its corresponding chi2 value calculated with an approximate variance (1/12) was conservative. The exact chi2 test of Ridit analysis should be used when comparing multiple groups in the clinical researches because of its special merits such as distribution of mean ridit value on (0,1) and clear graph expression. The exact chi2 test of Ridit analysis can be output directly by proc freq of SAS8.2 with ridit and modridit option (SCORES =).

CONCLUSIONThe exact chi2 test of Ridit analysis is equivalent to the Kruskal-Wallis H test, and should be used when comparing multiple groups in the clinical researches.

PURPOSE: The purposes of this study were to assess the trend of use of statistical methods including parametric and nonparametric methods and to evaluate the use of complex statistical methodology in recent periodontal studies. METHODS: This study analyzed 123 articles published in the Journal of Periodontal & Implant Science (JPIS) between 2010 and 2014. Frequencies and percentages were calculated according to the number of statistical methods used, the type of statistical method applied, and the type of statistical software used. RESULTS: Most of the published articles considered (64.4%) used statistical methods. Since 2011, the percentage of JPIS articles using statistics has increased. On the basis of multiple counting, we found that the percentage of studies in JPIS using parametric methods was 61.1%. Further, complex statistical methods were applied in only 6 of the published studies (5.0%), and nonparametric statistical methods were applied in 77 of the published studies (38.9% of a total of 198 studies considered). CONCLUSIONS: We found an increasing trend towards the application of statistical methods and nonparametric methods in recent periodontal studies and thus, concluded that increased use of complex statistical methodology might be preferred by the researchers in the fields of study covered by JPIS.
Data Interpretation, Statistical ; Periodontal Diseases ; Statistics, Nonparametric

Conventional statistical tests are usually called parametric tests. Parametric tests are used more frequently than nonparametric tests in many medical articles, because most of the medical researchers are familiar with and the statistical software packages strongly support parametric tests. Parametric tests require important assumption; assumption of normality which means that distribution of sample means is normally distributed. However, parametric test can be misleading when this assumption is not satisfied. In this circumstance, nonparametric tests are the alternative methods available, because they do not required the normality assumption. Nonparametric tests are the statistical methods based on signs and ranks. In this article, we will discuss about the basic concepts and practical use of nonparametric tests for the guide to the proper use.
Data Interpretation, Statistical ; Investigative Techniques ; Statistics, Nonparametric

OBJECTIVE: To compare dentoalveolar and skeletal changes produced by the pendulum appliance (PA) and the distal screw appliance (DS) in Class II patients. METHODS: Forty-three patients (19 men, 24 women) with Class II malocclusion were retrospectively selected for the study. Twenty-four patients (mean age, 12.2 +/- 1.5 years) were treated with the PA, and 19 patients (mean age, 11.3 +/- 1.9 years) were treated with the DS. The mean distalization time was 7 months for the PA group and 9 months for the DS group. Lateral cephalograms were obtained at T1, before treatment, and at T2, the end of distalization. A Mann-Whitney U test was used for statistical comparisons of the two groups between T1 and T2. RESULTS: PA and DS were equally effective in distalizing maxillary molars (4.7 mm and 4.2 mm, respectively) between T1 and T2; however, the maxillary first molars showed less distal tipping in the DS group than in the PA group (3.2degrees vs. 9.0degrees, respectively). Moreover, significant premolar anchorage loss (2.7 mm) and incisor proclination (5.0degrees) were noted in the PA group, whereas premolar distal movement (1.9 mm) and no significant changes at the incisor (0.1degrees) were observed in the DS group. No significant sagittal or vertical skeletal changes were detected between the two groups during the distalization phase. CONCLUSIONS: PA and DS seem to be equally effective in distalizing maxillary molars; however, greater distal molar tipping and premolar anchorage loss can be expected using PA.
Bicuspid ; Humans ; Incisor ; Male ; Malocclusion ; Molar* ; Retrospective Studies ; Statistics, Nonparametric

To identify the genetic factors influencing complex diseases is a challenging problem. With the development of several technologies, such as large-scale genome sequencing, gene chips and mass spectrometry, and the successful completion of the first phase of International HapMap Project, it is feasible to explore the associations between hundreds of polymorphisms in the human genome, even the whole genome, and complex diseases in populations with large number of samples. The present paper briefly describes the results of the International HapMap Project, the merging whole-genome association study, and some new methods applicable to data including multiple loci.
Bayes Theorem ; Computational Biology ; methods ; Genetic Predisposition to Disease ; Haplotypes ; Human Genome Project ; Humans ; Statistics, Nonparametric

UNLABELLEDTo introduce the application of a multifactor dimensionality reduction-genotype pedigree disequilibrium test (MDR-PDT) for detecting gene-gene interactions in the etiology of complex disease. A brief overview on the basic theory, implementing steps and features of MDR-PDT were described, and a practical research case was demonstrated to application of MDR-PDT in nuclear family studies. The MDR-PDT approach was the extension or development of conventional MDR method which could be used for detecting gene-gene interactions in families of diverse structure.

CONCLUSIONMDR-PDT was a new nonparametric and model-free method which might use additional family members in the nuclear families and had a good power to identify gene-gene interactions.

Missing data represent a general problem in many scientific fields, especially in medical survival analysis. Dealing with censored data, interpolation method is one of important methods. However, most of the interpolation methods replace the censored data with the exact data, which will distort the real distribution of the censored data and reduce the probability of the real data falling into the interpolation data. In order to solve this problem, we in this paper propose a nonparametric method of estimating the survival function of right-censored and interval-censored data and compare its performance to SC (self-consistent) algorithm. Comparing to the average interpolation and the nearest neighbor interpolation method, the proposed method in this paper replaces the right-censored data with the interval-censored data, and greatly improves the probability of the real data falling into imputation interval. Then it bases on the empirical distribution theory to estimate the survival function of right-censored and interval-censored data. The results of numerical examples and a real breast cancer data set demonstrated that the proposed method had higher accuracy and better robustness for the different proportion of the censored data. This paper provides a good method to compare the clinical treatments performance with estimation of the survival data of the patients. This pro vides some help to the medical survival data analysis.
Algorithms ; Breast Neoplasms ; epidemiology ; Female ; Humans ; Probability ; Statistics, Nonparametric ; Survival Analysis

OBJECTIVETo establish a non-parametric probabilistic model for evaluation of Chinese dietary exposure and to improve the assessment accuracy while integrating into the global risk assessment on food safety.

METHODSContamination data was from the national food contamination monitoring program during 2000 - 2006, including heavy metals, pesticides and mycotoxins, amounting to 135 contaminants with 499 commodities and 487 819 samples. Food consumption data was obtained from the national diet and nutrition survey conducted in 2002 with three consecutive days by 24-hour recall method, and 66 172 consumers were included. Monte Carlo simulation was applied to derive the intake distribution, and the uncertainty of each percentile was estimated using the Bootstrap sampling.

RESULTSDifferent non-parametric probabilistic models for dietary exposure evaluation on heavy metals, pesticides and some of the toxins were established for Chinese people, and intake distributions with 95% confidence intervals of these contaminants were estimated. Taking acephate as an example, the results of its model shows that, for the 7 - 10 year-old children, the median dietary exposure in urban and rural areas were 1.77 microg x kg(-1) x d(-1) and 2.48 microg x kg(-1) x d(-1) respectively, with a 95% confidence interval of (1.59 - 2.06) microg x kg(-1) x d(-1) and (2.33 - 2.80) microg x kg(-1) x d(-1) respectively.

CONCLUSIONThe non-parametric probabilistic model can quantify the variability and uncertainty of exposure assessment and improve the assessment accuracy.

PURPOSE: The purpose of this study was to identify effects of a self-management program on self-efficacy and compliance in patients with CHF. Hypothesis: 1) Patients with CHF who are provided with a self-management program will show higher self-efficacy scores than a control group. 2) Patients who are provided with a self-management program will show higher compliance scores than a control group. METHOD: This study was designed as a nonequivalent non-synchronized pre-posttest control group. There were eight patients in the experimental group, and twelve in the control group. According to NYHA classification, all patients belonged under the classesl to lV. Data were collected using the instruments developed by the researchers. Data were analyzed using descriptive statistics and Mann Whitney U test. RESULT: There were significant differences in self-efficacy scores and compliance scores between the experimental and control group. CONCLUSION: By utilizing the program, patients were able to monitor their symptoms routinely, comply with therapeutic regimen, and feel better able to positively influence their disease. Therefore, better compliance means fewer readmissions of patients with CHF.
Classification ; Compliance* ; Decision Trees* ; Heart Failure* ; Heart* ; Humans ; Self Care* ; Statistics, Nonparametric ; Surveys and Questionnaires

PURPOSE: This study was done to assess effects of women focused relapse prevention program on abstinence self-efficacy and depression in alcoholic women. METHODS: This study was a non-equivalent control group non-synchronized design with two groups, an experimental group (13 patients) and a control group (16 patients). The instruments were the Situational Confidence Questionnaire (SCQ-39) and the Beck depression Inventory (BDI). Data collection was done between July and December, 2008, during which a pre-test, the total of 8 group sessions for four weeks, and a post-test were given to alcoholic women who were admitted to K hospital in U city and D hospital in G city. The collected data were analyzed using descriptive statistics, Fisher's exact test, Mann-Whitney U test and ANCOVA with SPSS/WIN program. RESULTS: The scores for abstinence self-efficacy were significantly higher and for depression lower, for the experimental group after the women focused relapse prevention program. CONCLUSION: This study shows that the women focused relapse prevention program can be applied as an effective nursing intervention by clinical nurses.
Alcoholics* ; Data Collection ; Depression* ; Female ; Humans ; Nursing ; Questionnaires ; Recurrence* ; Statistics, Nonparametric