Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Data Analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 937 records · Page 52Linked to original sources

[Use of multidimensional data analysis in the processing of results from a gerontological study].

Relationship between the examined signs were searched for in a group of 428 persons selected in retirement dormitories in the East-Bohemian Region by means of cluster analysis of variables and factor analysis of chosen quantities. The stage of physical health, self-sufficiency, activity, adaptation, idea of the stay in the dormitory and cooperation with the staff are associated one with another. The age and data concerning social situation prior to entering the pensioners' dormitory (living conditions, education, occupation) have probably no direct effect on main characteristics of persons living there.

Aged↗

The use of catheter-tipped pressure transducers for chronic measurement of genital tract pressures in the ewe. I. Implantation technique, catheter performance and data analysis.

A computerised system for chronic in vivo monitoring of genital tract pressure in the ewe is described. Solid-state, catheter-tipped pressure transducers were surgically implanted in the uterine tube (ampulla), ipsilateral uterine horn and abdomen of five non-pregnant parous ewes. The catheters were connected to a portable computer which recorded the pressure at each location once per second and was programmed to analyse the data as mean pressure and area under the contraction curve over given periods. The catheters remained implanted for up to 129 days and 252 daily recordings were made. Analysis of spontaneous activity showed little variation in mean pressure of work done over four successive ten-minute periods. Although the amplitude of uterine contractions varied quite dramatically, chiefly in relation to variation in the plasma progesterone concentration, ampullary activity was unaffected by such changes. Genital tract pressures did not appear to be influenced by abdominal events. The catheters provoked minimal tissue reaction, and it is suggested that the system is suitable for chronic in vivo recording of genital tract pressure in the ewe.

Journal Article↗

Artefacts in 24-h pharyngeal and oesophageal pH monitoring: is simplification of pH data analysis feasible?

BACKGROUND: Ambulatory 24-h dual-channel pharyngeal and oesophageal pH monitoring is the standard test for measuring gastro-oesophageal and gastropharyngeal reflux. Artefacts caused by the intake of food may result in falsely positive gastropharyngeal reflux, which necessitates a manual review of 24-h pH data. The purpose of the study was to investigate the influence of meals and whether leaving out meals affected the reliability of the test. METHODS: Patients referred for otolaryngological complaints, suspected to have been caused by gastro-oesophageal reflux, underwent 24-h dual-channel pH monitoring. The raw unprocessed pH data were corrected by visual inspection of the 24-h tracings (corrected data), by leaving out meals or meals plus a 2-h postprandrial period. RESULTS: The raw pH data were substantially influenced by artefacts of food intake and pseudoreflux. Data obtained by leaving out meals agreed best with manually corrected data. Many of the falsely positive reflux episodes could be removed, thereby inducing a 9%-18% chance of undetected reflux. When examining the fraction of time supine, manually corrected data and data leaving out meals were fully concordant and detected 79% of patients with gastropharyngeal reflux. However, leaving out meals plus a 2-h postprandrial period resulted in 21%-50% falsely negative tests. CONCLUSION: Leaving out the period of intake of meals and beverages from the raw pH data might be the second best test after the time-consuming visual correction with a small chance of undetected gastropharyngeal reflux. For scientific purposes and when in doubt, it remains necessary to review the computer-generated data manually to discover every gastropharyngeal reflux event.

Adult↗

[Data analysis on the causes of death through disease surveillance program in Gansu province in the early 1990's].

In order to observe the changes of the causes of death among the residents in Gansu, mortality and years of porential life lost (YPLL) are used in this article to analyse the data of causes of death in 1990-1994. Data indicates that the average mortality of residents was 591.98 per 100,000. The main sequence were as below: respiratory diseases, cardiorasculor and cerebrovascalar diseases, neoplasms, injuries and pediatric diseases. Chronic diseases take up 74.4% of an mortalities. Average YPLL was 55.84/1000. YPLL sequence was as follows: injuries, neoplasms, respiratory system diseases, infectious diseases, cardiorascular diseases.

Accidents↗

CyDAS: a cytogenetic data analysis system.

For statistical analyses in cancer cytogenetics, the genomic changes encoded by the karyotype must be translated into numerical codes. We developed a program, which extracts chromosomal gains and losses as well as breakpoints from the karyotype. The changes are compiled in tables according to the chromosome bands involved and/or depicted in projection to the respective chromosome ideogram. The data are ready to be integrated into further statistical analyses. The program may be run as desktop or Internet application.

Chromosome Aberrations↗

[Intraoperative blood requirements and allogeneic blood transfusion in cardioanesthesia. Data analysis of 7729 patients in 12 cardiac surgical clinics].

UNLABELLED: Allogeneic blood requirements in cardiac surgery shows a wide variation even for comparable procedures. The aim of the present study was to compare the intraoperative allogeneic blood requirement in defined cardiac operations among 12 cardiac centers in Germany. METHOD: A data set with 25 variables concerning the intraoperative course in adult cardiac patients with myocardial revascularization, valve replacement (aortic or/and mitral valve) or combined procedures was distributed to the participating centers. The data of all patients between January 1th 1998 and June 30th 1998 were included. Besides demographic data, the intraoperative transfusion of allogeneic and autologous blood, fresh frozen plasma and the concomitant hematocrit values were registered. Data were analyzed for all centers and separated for each center. RESULTS: The data of 7,729 patients were analyzed. The intraoperative allogeneic blood requirement was 0.6 +/- 1.3 units for all patients. It varied among the centers from 0.25 +/- 0.6 units to 0.97 +/- 1.6 units (P < 0.05). The percentage of patients receiving allogeneic blood was 27% and differed among the centers from 17% to 35%. Female patients were transfused in 53% (36-39%) compared to male patients with 16% (9-20%) (P < 0.05). The rate of autologous blood predonation varied from 0.5% to 23%. Patients without autologous predonation were transfused in 28% compared to 4% in patients with predonation (P < 0.05). In patients with autologous predonation the intraoperative transfusion of allogeneic blood was significantly reduced (0.1 +/- 0.39 vs 0.6 +/- 1.4 units, P < 0.05). However, some centers with a high percentage of autologous predonation also demonstrated a high rate of perioperative allogeneic transfusion. CONCLUSION: The incidence of allogeneic blood transfusion in cardiac surgery depends on the institution and not on the surgical procedure. A common threshold value of hemoglobin for the transfusion of blood trigger even for comparable procedures could not be detected among the centers. Especially in female patients, there was a wide variation in allogeneic blood transfusion. Autologous blood predonation reduces blood requirement significantly, however, it is practiced with variing intensity. The data set did not include information about transfusion regimen in the postoperative period, thus, these data do not allow to draw conclusions for the whole perioperative period.

Adult↗

The epidemiology of breast cancer in Maori women in Aotearoa New Zealand: implications for ethnicity data analysis.

AIM: To describe the methods used to estimate breast cancer incidence and mortality in Maori and non-Maori women using multiple adjustors to assign ethnicity. METHODS: Age-specific incidence and mortality rates for breast cancer in Maori and non-Maori were calculated using registration and deaths data obtained from New Zealand Health Information Service (NZHIS) for 1996-2000. Four different methods were used to assign total and sole ethnicity: New Zealand Census Mortality Study (NZCMS)-adjusted, ever Maori-adjusted, National Health Index (NHI)-adjusted, and unadjusted source information. RESULTS: Unadjusted and NHI-adjusted estimates were least similar to the NZCMS-adjusted estimate used as the 'gold standard' in this study. Ever Maori-adjusted results closely approximated NZCMS-adjusted results in both incidence and mortality data. Sole Maori breast cancer incidence and mortality estimates were generally higher than total Maori estimates. DISCUSSION: Using four different estimates to assign ethnicity confirms previous findings showing poor quality of ethnicity data in routinely collected datasets. Future calculations of breast cancer incidence and mortality rates should assign total and sole ethnicity and reduce ethnicity misclassification by using NZCMS or ever Maori-adjusted estimates. This paper supports the need to collect better quality ethnicity data in order to identify and monitor Maori vs non-Maori cancer inequalities.

Breast Neoplasms↗

Large-scale gene expression data analysis: a new challenge to computational biologists.

The use of high-density DNA arrays to monitor gene expression at a genome-wide scale constitutes a fundamental advance in biology. In particular, the expression pattern of all genes in Saccharomyces cerevisiae can be interrogated using microarray analysis where cDNAs are hybridized to an array of each of the approximately 6000 genes in the yeast genome. In this survey I review three recent experiments related to transcriptional regulation and discuss the great challenge for computational biologists trying to extract functional information from such large-scale gene expression data.

Animals↗

Two-level Haseman-Elston regression for general pedigree data analysis.

The Haseman-Elston (HE) (Haseman and Elston [1972] Behav Genet 2:3-19) method is widely used in genetic linkage studies for quantitative traits. We propose a new version of the HE regression model, a two-level HE regression model (tHE) in which the variance-covariance structure of family data is modeled under the framework of multiple-level regression. An iterative generalized least squares (IGLS) algorithm is adopted to handle the varying variance-covariance structures across families in a simple fashion. In this way, the tHE can compete favorably with any current version of HE in that it can naturally make use of all the trait information available in any general pedigree, simultaneously incorporate individual-level and pedigree-level covariates, marker genotypes for linkage (i.e., the number of allele shared identically by descent [IBD]), and marker alleles for association. Under the assumption of normality, the method is asymptotically equivalent to the usual variance component model for detecting linkage. For the situation where the assumption of normality is critical, a robust globally consistent estimator of the quantitative trait locus (QTL) variance is available. Complex genetic mechanisms, including gene-gene interaction, gene-environmental interaction, and imprinting, can be directly modeled in this version of HE regression.

Genetic Diseases, Inborn↗

Using voxel-specific hemodynamic response function in EEG-fMRI data analysis: An estimation and detection model.

Research groups who study epileptic spikes with simultaneous EEG-fMRI have used mostly the general linear model (GLM). A shortcoming of the GLM is that the specification of a simple hemodynamic response function (HRF) may lead to biased results. Other methods, which predict the hemodynamic response from the measured data, have been termed "recognition models". The merit of recognition models lies in the power of estimating the region-specific or voxel-specific HRF. We propose an approach that merges these two models in a general framework: estimate the HRF on the training data sets, and applying the estimated HRF on the other part of the data sets. The merit of this framework is that it can utilize the advantages of both models. A comparison of performance is made between the GLM with three fixed HRFs and the new model with voxel-specific HRFs. The main results are as follows: (1) in 18 of the 21 patients, the new model has a higher adjusted coefficient of multiple determination than the GLM with fixed HRF; (2) in some subjects, with the new model, we found areas of activation that had not been detected with the three fixed HRFs at our threshold of significance. The results suggest that the new model can do better than the fixed HRF GLM for the analysis of epileptic activity with EEG-fMRI.

Electroencephalography↗

Outcomes associated with initiation of different controller therapies in a Medicaid asthmatic population: a retrospective data analysis.

BACKGROUND: Outcomes in asthmatic patients may vary depending on the controller medication used. Observational studies of outcomes of asthma therapy are needed to understand the implications of choice of controller in different populations. OBJECTIVES: To determine whether there are differences in health care use and costs of asthma treatment in asthma patients treated with montelukast compared with fluticasone proponiate 44 microg. METHOD: Using data from the North Carolina Medicaid program, we compared continuously enrolled asthmatic patients starting either fluticasone propionate 44 microg (FP44), an inhaled corticosteroid (ICS) (n = 312), or montelukast 5 and 10 mg, an oral leukotriene modifier (LM) (n = 398) between the years 1998 and 1999. A secondary analysis compared continuously enrolled asthmatic patients already using ICS as controller therapy initiating either salmeterol (long-acting beta-agonist) (n = 97) or montelukast (n = 101) in the year 1998. Patients were followed for 1 year pre- and postcontroller or additional controller initiation for health care service use, medication refill patterns, and costs. RESULTS: There were no significant differences in the adjusted asthma-related health care costs between the montelukast and FP44 groups. In both groups, physician visits were significantly higher in year 2 (p < 0.01) than in year 1. We found montelukast users to be more adherent with prescription refills (using measures of medication possession) even after allowing for a wider adherence range for FP (RR = 2.53; 95% CI = 1.50-4.26), although patients using montelukast were more likely than patients with fluticasone to switch controller pharmacotherapy (RR = 1.53; 95% CI = 1.12-2.09). Similarly, there were no differences in health care service use and costs between the montelukast and salmeterol groups, with the exception of a 33% reduction (p < 0.01) in number of inhaled corticosteroid refills in the second year in the salmeterol group. CONCLUSION: There were no cost and major health care use differences between the two primary or secondary controller therapies in the postinitiation year. Although FP was associated with lower rate of controller switch, montelukast use was associated with significantly better treatment adherence in patients with treatment persistence in this population of Medicaid-enrolled asthmatic patients. The addition of salmeterol as additional controller was associated with a significant decrease in inhaled corticosteroid use, suggesting decreased adherence in patients on the two-drug regimen.

Acetates↗

Breast cancer: critical data analysis concludes that estrogens are not the cause, however lifestyle changes can alter risk rapidly.

BACKGROUND: The theory that estrogens are causally associated with increased risk of breast cancer and the question of whether lifetime cumulative exposure is necessary are critically reviewed. METHODS: Systematic search was made of published epidemiological and clinical data relating to estrogen concentrations at different times and situations, and of breast cancer incidence with age and after lifestyle changes. RESULTS: Breast cancer incidence increases with age, although the rate of increase slows. Reproductive factors are known to affect risk, but data that do not fit the theory of estrogen causation include low estradiol levels and decline of estrogen excretion postmenopausally, rates in HRT-takers, absence of increased rate during or after pregnancy, and breast cancer in men. Breast cancer risk can be altered by external factors within a few years, as shown by studies in both Norway and England during World War II, by changing rates in migrant populations, and by the effect on rates of recent adiposity. CONCLUSIONS: It is probable that estrogens act as promoters rather than being directly causal. Even as promoters, lifetime exposure to estrogens is not necessary. The cause is most probably a lifestyle factor, changes in which can rapidly alter risk. This has important implications in the search for a causative factor.

Animals↗

Pulmonary abnormalities and PET data analysis: a retrospective study.

PURPOSE: To assess methods of standard uptake ratio (SUR) calculation with 2-deoxy-2-[fluorine-18]fluoro-D-glucose (FDG) positron emission tomography (PET) in indeterminate focal pulmonary abnormalities. MATERIALS AND METHODS: One hundred ninety-seven adult patients with indeterminate pulmonary abnormalities had complete FDG PET data, consistent methods of data acquisition, and definitive diagnosis with tissue biopsy or negative 2-year follow-up findings. PET studies were evaluated by using SURs calculated with the average or maximum region-of-interest pixel value in the numerator and with weight, lean body mass, or body surface area in the denominator. RESULTS: One hundred twenty malignant lesions and 77 benign processes were identified. Receiver operating characteristic (ROC) curve areas were statistically significantly larger with the average rather than the maximum pixel value in the calculation of the SUR for any of the three denominators (P < or = .05). SURs calculated with weight versus lean body mass versus body surface area in the denominator showed no statistically significant difference in ROC curve areas. CONCLUSION: SURs determined by using average pixel values provide statistically significant improvement in ROC curve areas over those determined by using maximum pixel values. Weight, lean body mass, and body surface area in the denominator of the SUR calculation provide equivalent ROC curve areas and are therefore equivalent in accuracy in this population.

Adult↗

Relationship Between Number of Acute Pancreatitis Episodes and Risk of New-onset Diabetes in the U.S.: A Real-world Data Analysis.

INTRODUCTION: Acute pancreatitis (AP) is a common inflammatory disorder that is associated with increased risk for diabetes mellitus (DM). It remains unclear whether recurrent acute pancreatitis (RAP) is associated with further increased risk of incident DM. This study aims to investigate the association between RAP and incident DM using real-world data. METHODS: We conducted a retrospective cohort study using the MerativeTM MarketScan&#xae; claims database (2016-2023), identifying patients with AP and no prior history of DM at baseline. The primary exposure of interest, RAP, was defined as one or more episodes of AP occurring &#x2265;90 days after the index AP diagnosis, whereas one episode of AP referred to a single episode of AP (SAP) with no subsequent recurrence within 90 days following the index event. A multivariable stratified Cox proportional hazards regression models were used to determine the association between RAP and incident DM, identified using ICD-10 codes. RESULTS: In total, 16,184 individuals with AP (mean [SD] age: 45.8 [12.3]) contributed 40,712 person-years of follow-up, during which 1,477 incident cases of DM were documented. Individuals with RAP had an increased risk of incident DM compared with those with a SAP(adjusted HR, 1.92; 95% CI, 1.61-2.29). The risk increased significantly with the frequency of RAP. In comparing the modifying effect of patient demographics and comorbidities, a stronger association between RAP and incident DM was observed in females (adjusted HR, 2.44; 95% CI, 1.87-3.19) than in males (adjusted HR, 1.64; 95% CI, 1.30-2.07; Pinteraction=0.03). Also, stronger associations were observed among younger patients (18-46&#xa0;y) (adjusted HR=2.56; 95% CI, 1.97-3.31) and among non-tobacco abuse (adjusted HR=2.19; 95% CI, 1.81-2.65), with significant interactions for all comparisons (Pinteraction<0.05. CONCLUSIONS: In this real-world study, RAP was associated with an increased risk of incident DM. Our findings highlight an opportunity for glycemic monitoring and proactive management of patients with RAP to mitigate their risk of developing DM.

AP↗

Canadian heart health surveys: a profile of cardiovascular risk. Survey methods and data analysis. Canadian Heart Health Surveys Research Group.

OBJECTIVE: To describe the methods used in nine provincial surveys carried out as part of the Canadian Heart Health Initiative. DESIGN: Population-based cross-sectional surveys, following a core standardized protocol, implemented by provincial departments of health in collaboration with Health and Welfare Canada. Data were obtained through a home interview and a clinic visit. A standard manual of field operations and standardized training procedures were used in all provinces. SETTING: Nine Canadian provinces during the period 1986 to 1990. PARTICIPANTS: A probability sample of 26,293 men and women aged 18 to 74 years was selected from the health insurance registries in each province. Over 30% of the participants had post-secondary education. About 50% were 18 to 34 years old. OUTCOME MEASURES: Data on sociodemographic characteristics, hypertensive and diabetic status, knowledge and awareness of the causes and consequences of cardiovascular disease and two blood pressure measurements were obtained in a home interview. During a clinic visit, data were collected on height, weight (waist and hip circumferences in four provinces), two blood pressure measures and a blood sample. Total plasma cholesterol, triglycerides and high- and low-density lipoprotein cholesterol were measured in the Lipid Research Laboratory, University of Toronto and St. Michael's Hospital. MAIN RESULTS: Of the subjects invited to participate in the survey, 78% were interviewed, 69% attended the clinic and 64% provided a fasting specimen (8 hours or more). The response rates were slightly lower for men aged 18 to 34, for women aged 65 to 74 and for those with fewer years of education. Data from the provincial surveys (Ontario will complete the survey in 1992) are being compiled in the Canadian Heart Health Database. CONCLUSION: The process followed in the implementation of the provincial heart health surveys is a model of how provincial departments of health may carry out epidemiologic investigations in support of their mandate. The approach illustrates how a country-wide database can be built through partnerships among different levels of government. The use of community health nurses was instrumental in the efficient implementation of the surveys and in the realization of the relatively high rates of response attained.

Adult↗

[Hematological data analysis in children with thalassemia trait or hemoglobin H disease in Taiwan].

In the past several years, we have collected 91 cases diagnosed as beta-thalassemia trait, 94 cases as alpha-thalassemia trait and 43 cases as hemoglobin H disease. The ages ranged from 6 months to 15 years. The hematological data were analyzed. We calculated the mean +/- SD for each item of the erythrocyte indices (RBC, Hgb, Hct, MCV, MCH, MCHC, +/- RDW) and the Hb electrophoretic results (Hb A, Hb A2, Hb F, Hb H & Bart's) in each group, and tabulated them. Then, comparisons were made between beta and alpha-thalassemia traits or between the thalassemia trait and hemoglobin H disease. We found that each of the mean values for Hgb, Hct, MCV and MCH for children with the beta-thalassemia trait was significantly lower than that for children with the alpha-thalassemia trait. The mean MCV value of the beta-thalassemia trait group was 60.7 +/- 3.4 fl, and 87% of the MCV values in this group ranged from 55 to 65 fl. The mean MCV value for the alpha-thalassemia trait group was 63.3 +/- 3.3 fl, and 56% of the MCV values in this group ranged from 60-65 fl. The MCV values for all of the 185 children studied with either the beta- or alpha-thalassemia trait ranged from 54 to 71 fl, and were far below the normal ranges for MCV values for each age-specific group. The mean percentage of deviation of MCV from normal was greater than that of Hgb in both the beta- and alpha-thalassemia trait groups. A comparison of those with beta-thalassemia trait 6 years old and under and those over 6 years showed that both the mean values of RBC and Hgb were higher in the older subgroup, while the mean MCV values did not show any significant differences between these 2 subgroups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗