PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “data analysis”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 703 records · Page 39Linked to original sources
PubMed2002

[The AIRE Study: data analysis of 753 European children with asthma].

PROBLEM: To analyse the paediatric data from the AIRE study (Asthma insights and reality in Europe) describing the standard of asthma control in Europe. MATERIAL AND METHODS: Among the 73,880 households contacted by telephone in 7 countries 753 children under the age of 16 were identified. An interview was conducted with a close relative to determine the frequency and severity of symptoms during the recent month, visits to casualty and hospital admissions during the past year, the medications used, the effects on the lives of the children, the opinions of the parents on the level of control of asthma and the monitoring methods used. RESULTS: 38.2% of children reported diurnal symptoms and 28% disturbance of sleep at least once a week. The consequences were important: limitation of sporting activities (29.5%) and absence from school (42.7% in the past year). Treatment was inadequate: 26% of children used inhaled steroids yet 45.9% had persistent asthma. The level of control was overestimated: 61% of parents of children with severe persistent asthma considered the asthma to be well controlled. CONCLUSION: European asthmatic children are poorly controlled, under-treated and rarely followed up. The consequences, particularly absence from school, should stimulate an improvement in their therapeutic and educational management.

Absenteeism↗
PubMed1994

Data analysis.

Explore the source record for details and available documents.

Data Interpretation, Statistical↗
PubMed2002

Software and methods for oligonucleotide and cDNA array data analysis.

Two HTML-based programs were developed to analyze and filter gene-expression data: 'Bullfrog' for Affymetrix oligonucleotide arrays and 'Spot' for custom cDNA arrays. The programs provide intuitive data-filtering tools through an easy-to-use interface. A background subtraction and normalization program for cDNA arrays was also built that provides an informative summary report with data-quality assessments. These programs are freeware to aid in the analysis of gene-expression results and facilitate the search for genes responsible for interesting biological processes and phenotypes.

Computational Biology↗
PubMed2005

Comprehensive post-genomic data analysis approaches integrating biochemical pathway maps.

Post-genomic era research is focusing on studies to attribute functions to genes and their encoded proteins, and to describe the regulatory networks controlling metabolic, protein synthesis and signal transduction pathways. To facilitate the analysis of experiments using post-genomic technologies, new concepts for linking the vast amount of raw data to a biological context have to be developed. Visual representations of pathways help biologists to understand the complex relationships between components of metabolic networks, and provide an invaluable resource for the integration of transcriptomics, proteomics and metabolomics data sets. Besides providing an overview of currently available bioinformatic tools for plant scientists, we introduce BioPathAt, a newly developed visual interface that allows the knowledge-based analysis of genome-scale data by integrating biochemical pathway maps (BioPathAtMAPS module) with a manually scrutinized gene-function database (BioPathAtDB) for the model plant Arabidopsis thaliana. In addition, we discuss approaches for generating a biochemical pathway knowledge database for A. thaliana that includes, in addition to accurate annotation, condensed experimental information regarding in vitro and in vivo gene/protein function.

Computational Biology↗
PubMed1993

Exploratory data analysis of three sexual behaviour surveys: implications for HIV-1 transmission in the U.K.

Recently, the number of European and North American heterosexually transmitted AIDS cases has begun to increase. It appears that injecting drug users may be acting as an important infection source for heterosexual transmission, and that the HIV-1 epidemic may be slowly diffusing out into the general population. Therefore, the question arises, as to whether there will be an extensive heterosexually transmitted epidemic in Europe or North America. The possibility of such an epidemic occurring depends upon three factors: sexual mixing patterns, the prevalence and the distribution of specific risk factors, and changes in risk behaviours. To assess the potential for an extensive sustained heterosexually transmitted epidemic it is necessary to estimate these three factors by conducting large-scale linked behavioural and seroprevalence surveys. Unfortunately, such surveys have yet to be conducted in any country. However, a limited amount of sexual behaviour data are available from three small studies that have been conducted in the U.K. Although each of the studies suffers from methodological imperfections, together they may be used as the basis for a preliminary assessment of the potential effects of heterosexual transmission in the U.K. In this paper I discuss the results from an exploratory analysis of these data; the results are organized into five sections: (i) assessment of the prevalence and distribution of specific risk behaviours; (ii) determination of covariates of risk behaviours (and hence characterization of the subgroups that may be at risk); (iii) assessment of age-dependent sexual mixing patterns; (iv) assessment of sexual behaviour changes; and (v) calculation of epidemiological parameters. The validity and the reliability of the data from the three studies are assessed. The analysis suggests that it is possible that a heterosexually transmitted HIV-1 epidemic could occur in the U.K. Hence, it is essential to conduct longitudinal surveys that collect linked seroprevalence and behavioural data.

Adolescent↗
PubMed2026

Identification of Critical Genes for Recurrent Aphthous Ulcer by Transcriptome Data Analysis and Mendelian Randomization.

PURPOSE: Recurrent aphthous ulcer (RAU) is a common oral mucosal disorder with a poorly understood etiology, significantly affecting patients' quality of life. This study aims to investigate critical genes linked to RAU and explore their biological mechanisms using transcriptomic data and Mendelian randomization (MR) analysis. MATERIALS AND METHODS: RAU-related gene expression data from the GEO database (GSE37265) were analyzed to identify differentially expressed genes (DEGs). A two-sample MR approach was used to assess the causal impact of expression quantitative trait loci (eQTL) on RAU. Critical genes were identified by intersecting DEGs with significant MR findings. GO and KEGG pathway enrichment analyses were performed, along with GSEA and immune cell infiltration analysis, to investigate the functions and mechanisms of these genes in RAU. RESULTS: A total of 184 differentially expressed genes (DEGs) were identified, while 339 RAU-associated genes were screened through MR analysis. Cross-validation further identified 7 critical genes. Among these, CCR1, ERP27, HCK, MICB, and SLC2A3 showed protective associations with RAU risk, whereas CD177 and IFITM1 were positively associated with increased risk. Enrichment analysis revealed that these genes are involved in specific biological processes, including cell migration, immune response, and metabolic regulation, which are closely linked to RAU pathogenesis. CONCLUSION: This systematic study comprehensively investigates the critical causative genes underlying RAU, emphasizing the intricate relationships between immune regulation and metabolic disturbances in its pathology. These findings lay a solid foundation for the development of novel biomarkers and may inform future research on targeted therapeutic strategies for RAU.

Stomatitis, Aphthous↗
PubMed1996

The use of sampling weights for survey data analysis.

The use of the sampling weights when fitting models to complex survey data is considered. It is shown that when the sample is selected with unequal selection probabilities that are related to the values of the response variables even after conditioning on all the available design information, ignoring the sample selection scheme in the inference process, can yield misleading results. Probability weighting of the sample observations yields consistent estimators of the model parameters and protects against model misspecification, although in a limited sense. Other methods of incorporating the sampling weights in the inference process are discussed and compared to the use of probability weighting.

Health Surveys↗
PubMed1983

Trends in peptic ulcer related diseases from 1972 to 1980. Hospital activity analysis data and general practice cimetidine prescribing levels.

Between 1972 and 1980 Hospital Activity Analysis from 5 Northern Ireland Hospitals demonstrated a gradual increase in the number of patients discharged for all diagnoses whilst there was a decline in discharges for peptic ulcer related disease, (duodenal ulcer, gastric ulcer, gastrojejunal ulcer, peptic ulcer site unspecified and hiatal hernia). The mean number of peptic ulcer related disease discharges per year for 1977-80, when cimetidine became generally available, was 10% lower than that of 1972-76, mainly due to a decline in male patient numbers. The mean annual number of male patients with a duodenal ulcer fell significantly by 18% (U = 1, p less than or equal to 0.025) during the 1977-80 period, whereas female discharges decreased by only 4%. Between 1972-76 and 1977-80 the mean annual number of duodenal ulcer perforations decreased significantly by 21% in males but only by 4% in females. Surgery for peptic ulcer related disease was 47% less in 1977-80 period, with significant decreases in duodenal ulcer, gastric ulcer and hiatal hernia procedures. From 1977 to 1980 there was considerable growth in Northern Ireland general practice cimetidine prescribing with 300,000 prescriptions being dispensed over the period. Apart from male duodenal ulcer cases, hospitalisation for peptic ulcer related diseases did not decrease substantially after the introduction of cimetidine but duodenal ulcer perforation and conditions warranting surgery did decline.

Cimetidine↗
PubMed2005

ParPEST: a pipeline for EST data analysis based on parallel computing.

BACKGROUND: Expressed Sequence Tags (ESTs) are short and error-prone DNA sequences generated from the 5' and 3' ends of randomly selected cDNA clones. They provide an important resource for comparative and functional genomic studies and, moreover, represent a reliable information for the annotation of genomic sequences. Because of the advances in biotechnologies, ESTs are daily determined in the form of large datasets. Therefore, suitable and efficient bioinformatic approaches are necessary to organize data related information content for further investigations. RESULTS: We implemented ParPEST (Parallel Processing of ESTs), a pipeline based on parallel computing for EST analysis. The results are organized in a suitable data warehouse to provide a starting point to mine expressed sequence datasets. The collected information is useful for investigations on data quality and on data information content, enriched also by a preliminary functional annotation. CONCLUSION: The pipeline presented here has been developed to perform an exhaustive and reliable analysis on EST data and to provide a curated set of information based on a relational database. Moreover, it is designed to reduce execution time of the specific steps required for a complete analysis using distributed processes and parallelized software. It is conceived to run on low requiring hardware components, to fulfill increasing demand, typical of the data used, and scalability at affordable costs.

Algorithms↗
PubMed2005

[Linking quantitation of electrophoresis pattern and data analysis in AFLP for Oncomelania hupensis].

OBJECTIVE: To search into a method for analyzing the quantitative data in amplified fragment length polymorphism (AFLP) electrophoresis. METHODS: Oncomelania snails collected from the field were screened. Forty snails found uninfected with schistosomiasis were divided randomly into two groups and used to isolate genomic DNA. AFLP electrophoresis pattern was first transformed into quantitative data by Glyko BandScan software, and the bands were read according to different standards of band-reading to acquire the corresponding data. These data sets were analyzed by genetic statistics to get an inference set, and the analysis of this inference set was performed to reach a summary description. RESULTS: The results of genetic variation from different standards of band-reading were different With the increase of the standard value of band-reading, the indices indicating the genetic polymorphism of Oncomelania hupensis population (e.g. Shannon's information index) also increased. When the standard value reached at certain level, the values of these indices began to decrease. Compared with the above indices, the change for gene flow turned out contrary to the genetic identity. The distributions of inference results from different standards of band-reading all showed significant normal distribution. The mean value of genetic variation based on total grey was very close to that on the proportion of total grey. The average genetic identity between the "subpopulations" was 0.956 according to proportion of total grey or 0.958 from the total grey with an average genetic distance between the "subpopulations" of 0.045 and 0.043 respectively. CONCLUSION: It seems to be a reasonable and accurate method by quantifying the AFLP electrophoresis pattern followed by analyzing the data through the use of the different standards of band-reading.

Animals↗
PubMed2004

Microarray data analysis: a hierarchical T-test to handle heteroscedasticity.

The analysis of differential gene expression in microarray experiments requires the development of adequate statistical tools. This article describes a simple statistical method for detecting differential expression between two conditions with a low number of replicates. When comparing two group means using a traditional t-test, gene-specific variance estimates are unstable and can lead to wrong conclusions. We construct a likelihood ratio test while modelling these variances hierarchically across all genes, and express it as a t-test statistic. By borrowing information across genes we can take advantage of their large numbers, and still yield a gene-specific test statistic. We show that this hierarchical t-test is more powerful than its traditional version and generates less false positives in a simulation study, especially with small sample sizes. This approach can be extended to cases where there are more than two groups.

Algorithms↗
PubMedDate not supplied

Multidimensional statistical data analysis of viral hepatitis report records.

The internal connections between the variables defined by the data obtained from viral hepatitis (VH) report records completed ih a Romanian county durihg 1973 are analysed. The mathematical model for linear factorial analysis allowed a simultaneous processing of all variables and the distinction of representative factors. The conclusions of the study suggest new possible approaches by the introduction of supplementary questions in the VH report records.

Factor Analysis, Statistical↗