Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Data Files”

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 829 records · Page 46Linked to original sources
PubMed2001

HbAlc in an unselected population of 4438 people with type 2 diabetes in a Danish county.

OBJECTIVE: To describe the use and level of HbA1c in a large unselected Type 2 diabetic population in Denmark. In addition, to describe the characteristics of the patients and the general practitioners in relation to the monitoring of HbA1c. DESIGN: Data were collected from public data files for the period January 1993 to December 1997. SETTING: The County of Vejle with a background population of 342,597 citizens, 303,250 of whom were listed with participating general practitioners. PATIENTS: The Type 2 diabetic population alive and resident in the county on 1 January 1997. RESULTS: In a population of 4438 Type 2 diabetics, 73% had a minimum of one annual HbA1c measurement in 1997. No HbA1c measurement was associated with a long history of diabetes, diet treatment or old age. Poor glycaemic regulation was found in 65% of the Type 2 diabetics in 1997. Poor glycaemic regulation was associated with tablet or insulin treatment, age under 70 years and long history of diabetes. The interpractice variation was huge. CONCLUSION: The quality of HbA1c monitoring of Type 2 diabetics needs to be improved. Possibilities for improvement seem to be present.

Aged↗
PubMed2005

2D versus 3D radiation therapy for prostate carcinoma: a direct comparison of dose volume parameters.

That three dimensional (3D) planning for radiation therapy (RT) of carcinoma of the prostate (CaP) improves radiation dosimetry to the tumour and reduces dose to the rectum and bladder compared with 2D planning, has not been properly evaluated. We addressed this by downloading the CT data files of twenty-two patients who had completed 2D planned RT for CaP onto a 3D planning system and re-planning RT using the same four field technique and dose prescription as the 2D technique. The radiation dose at 100%, 90%, 50% and 0% volumes (D100, D90, D50 and D0) of the Dose Volume Histograms (DVH's) of the GTV, PTV, rectum and bladder, the area under the curves of each DVH and the field sizes were evaluated and compared between the two sets of plans. Repeated measured t-tests were used to compare the means of the different measurements. The D100, D90 and D50 of the GTV, PTV and rectum were increased for the 3D versus the 2D plans (p < 0.05 for each parameter). The area under the rectal DVH was also greater for the 3D plans (p < 0.05). These changes are attributable to the larger field sizes, particularly the length in the 3D compared with the 2D plans.

Aged↗
PubMed2003

Causes of death in polymyalgia rheumatica. A prospective longitudinal study of 315 cases and matched population controls.

OBJECTIVE: To determine causes of death in patients with pure polymyalgia rheumatica (PMR) compared to matched population controls. METHODS: In a population based study from 1987-1997, 315 patients were diagnosed with PMR. The patients were each randomly assigned four population controls, totally 1,260 controls. The date and causes of death were identified from the data files at Statistics Norway up to the end of 1997. RESULTS: A total of 65 cases (20.6%) with PMR died compared to 338 (26.8%) among the controls (mortality rate ratio (MRR) = 0.73, 95% CI 0.56-0.97, p = 0.03). No statistically significant difference was found between patients and controls with regard to mortality from coronary heart disease or stroke (MRR=0.78, 95% CI 0.52-1.18), cancer (MRR = 0.59, 95% CI 0.30-1.17), and other causes (MRR=0.75, 95% CI 0.48-1.17). CONCLUSION: The increased survival found in patients with PMR could not be explained by reduction in any particular cause of death.

Aged↗
PubMed2002

Recipients in need of ancillary services and their receipt of HIV medical care in California.

For many individuals with access to quality medical care, HIV disease is no longer a critical short term illness but a chronic condition giving rise to more clients requiring ongoing medical care. Programs funded by the federal Ryan White Comprehensive AIDS Resources Emergency Act not only provide essential medical care for these individuals but also facilitate access to medical care services. These programmes fund services, including case management, transportation, and translation assistance, that feature ongoing assistance and enable individuals to remain in the health care system. Because of the importance of maintaining the strict drug regimen, retention in care is also an important part of the overall HIV care component. This study analyzed the relationship of ancillary services and a federal health programme client's receipt of medical care and retention in the health care system. We defined a cohort in need of ancillary services in part by a questionnaire designed to identify factors relating to need. These factors included education, language, and substance use. By merging client level data files we were able to identify medical service utilization trends among the individuals in the cohort who received a high number of ancillary services (more than 11 ancillary service visits in the two-year study period, n = 138) and those who received few services (fewer than six ancillary service visits in the two-year study period, n = 132). Results suggest that the receipt of ancillary services is associated with receipt of and retention in primary medical care. We found that for federal health programme clients in need of ancillary services, a positive relationship existed between their receipt of ancillary services and their access to primary medical care (p </= 0.001). This observation held constant when age, race, gender, and insurance coverage were controlled for. Also, these clients were more likely to be seen by a medical doctor at least once in three consecutive six-month periods when they received needed ancillary services (p </= 0.01).

Adult↗
PubMedDate not supplied

Relation of genotypes of alcohol metabolizing enzymes and mortality of liver diseases in patients with alcohol dependence.

The aim of this study was to investigate the relationship between alcohol metabolizing enzyme genotypes and mortality risk of liver diseases among patients with alcohol dependence. A total of 130 male patients with a DSM-III-R diagnosis of alcohol dependence (mean age 40+/-10 years) were recruited consecutively to the study from 1994 to 1995. Blood biochemistry and hepatitis B viral surface antigen (HBsAg) were measured. The genotypes of ADH2, ADH3 and ALDH2 were determined by polymerase chain reaction and restriction fragment-length polymorphism. The mortality cases were identified by matching data files of the death certification system of the National Department of Health issued from 1994 to 2001. Mortality analysis revealed that 58 of 130 cases (45%) died during the follow-up period. Among them, 21 cases died of liver diseases. Mortality was not higher in HBsAg positive than in negative subjects. The genotypes of alcohol metabolizing enzymes are not associated with the mortality risk of liver diseases. The small sample size was a limitation of this study. How functional genetic polymorphism of the alcohol metabolizing enzymes causes liver damage is still not clear. Continuous study of this topic is necessary.

Adult↗
PubMedDate not supplied

Family networks in prenatal and postnatal health.

This paper examines the effects of kin access on prenatal health practices, birth outcome, and postnatal health practice for infants born to black and white mothers ages 21 to 28 in the U.S. during 1984-86. The data used for this research were compiled from three sources: (1) The National Longitudinal Survey of Youth; (2) The Children of the National Longitudinal Survey of Youth; (3) special kin access data files, which were created specifically for this study. Logistic regression procedures are used to assess the effects of kin proximity, maternal grandmother proximity, and presence of the child's father on health practices (N = 1,030) and birth outcome (N = 1,385), controlling for the mother's educational attainment, work experience, poverty, presence of the child's father, and birth order of the child. We find no evidence supporting the notion that kin access positively affects the prenatal and postnatal health practices of young mothers. The results suggest that young mothers who reside with their mothers or other adult kin, and those who are in close proximity to them, are no more likely to seek prenatal care during the first trimester, or to avoid smoking or drinking during pregnancy. Mothers who live with a sexual partner or husband are, however, somewhat more likely to seek prenatal care and to avoid alcohol use during pregnancy. Closer kin access is associated with a lower probability of breastfeeding. These results suggest that it will not be adequate to rely on kin networks or kin assistance to improve the prospect of healthy birth outcomes.

Female↗
PubMedDate not supplied

Effect of maternal age on birth outcomes among young adolescents.

This study examined the effect of maternal age on birth outcomes among young adolescents, ages 10 through 15. All records representing single births of primipara, Black or White adolescents, were selected for analysis from the 1983-1986 National Center for Health Statistics' Public Use Linked Live Birth-Infant Death Data File (n = 127,668). Logistic regression analyses controlled for effects of maternal race, marital status, prenatal care, gravidity, education, and metropolitan/nonmetropolitan residency. Univariate analyses indicated that the youngest adolescents were at greatest risk for negative birth outcomes including very preterm and preterm delivery, low birth weight, small for gestational age (SGA), and neonatal mortality. Logistic analyses showed similar results, with the exception that differences in SGA were insignificant. This study indicates the importance of examining age-specific birth outcomes among a population that has traditionally been studied in aggregate and underscores the need for increased prevention efforts.

Adolescent↗
PubMedDate not supplied

Migration and substance use: evidence from the U.S. National Health Interview Survey.

Representative data from the U.S. National Health Interview Survey are used to investigate the substance use patterns of immigrants and compare them to those of the native born populations. The information examined is from the 1991 supplementary Drug and Alcohol Use Data File, which examined the self-reported substance use behaviors of approximately 21,000 adults aged 18-44. Findings indicate that immigrants to the U.S. in the late twentieth century are less likely to use alcohol and other drugs than are native born citizens. Additional findings suggest assimilation processes by which exposure to mainstream American society leads to patterns of alcohol and illicit drug use among long term immigrants that approximates that of the native born population. The patterns of substance use observed among immigrants, however, are not consistent with acculturative stress mechanisms. These findings provide an important and representative profile of the substance use patterns of one of the largest international migration streams of the past one hundred years.

Acculturation↗
PubMed1990

Cross sections and partial kerma factors for elastic and inelastic neutron scattering from nitrogen, oxygen and calcium at En = 21.6 MeV.

The Studsvik high-resolution, low-background time-of-flight facility has been used to measure differential neutron scattering cross sections for nitrogen, oxygen and calcium at a neutron energy of 21.6 MeV. Angular distributions in the range 10 degrees-160 degrees have been measured for both elastic and inelastic scattering from some low-lying levels in the three nuclei. Angle-integrated cross sections have been determined by fitting Legendre polynomial expansions to the differential data. Partial kerma factors for elastic and inelastic scattering have been deduced from these fits. Analyses in terms of the spherical optical model and the distorted-wave Born approximation have provided information on potential parameters and deformations, which have been used to calculate cross sections and partial kerma factors. Comparisons have been made with other recent data sets and model predictions, as well as with the evaluated neutron data file ENDF/B-V.

Calcium↗
PubMed2002

Energy spectra, angular spread, fluence profiles and dose distributions of 6 and 18 MV photon beams: results of monte carlo simulations for a varian 2100EX accelerator.

The purpose of this study is to provide detailed characteristics of incident photon beams for different field sizes and beam energies. This information is critical to the future development of accurate treatment planning systems. It also enhances our knowledge of radiotherapy photon beams. The EGS4 Monte Carlo code, BEAM, has been used to simulate 6 and 18 MV photon beams from a Varian Clinac-2100EX accelerator. A simulated realistic beam is stored in a phase space data file, which contains details of each particle's complete history including where it has been and where it has interacted. The phase space files are analysed to obtain energy spectra, angular distribution, fluence profile and mean energy profiles at the phantom surface for particles separated according to their charge and history. The accuracy of a simulated beam is validated by the excellent agreement between the Monte Carlo calculated and measured dose distributions. Measured depth-dose curves are obtained from depth-ionization curves by accounting for newly introduced chamber fluence corrections and the stopping-power ratios for realistic beams. The study presents calculated depth-dose components from different particles as well as calculated surface dose and contribution from different particles to surface dose across the field. It is shown that the increase of surface dose with the increase of the field size is mainly due to the increase of incident contaminant charged particles. At 6 MV, the incident charged particles contribute 7% to 21% of maximum dose at the surface when the field size increases from 10 x 10 to 40 x 40 cm2. At 18 MV, their contributions are up to 11% and 29% of maximum dose at the surface for 10 x 10 cm2 and 40 x 40 cm2 fields respectively. However, the fluence of these incident charged particles is less than 1% of incident photon fluence in all cases.

Electrons↗
PubMed2004

The modelling of positron emitter production and PET imaging during carbon ion therapy.

At the carbon ion therapy facility of GSI Darmstadt in-beam positron emission tomography (PET) is used for imaging the beta+-activity distributions which are produced via nuclear fragmentation reactions between the carbon ions and the atomic nuclei of the irradiated tissue. On the basis of these PET images the quality of the irradiation, i.e. the position of the field, the particle range in vivo and even local deviations between the planned and the applied dose distribution, can be evaluated. However, for such an evaluation the measured beta+-activity distributions have to be compared with those predicted from the treatment plan. The predictions are calculated as follows: a Monte Carlo event generator produces list mode data files of the same format as the PET scanner in order to be processed like the measured ones for tomographic reconstruction. The event generator models the whole chain from the interaction of the projectiles with the target, i.e. their stopping and nuclear reactions, the production and the decay of positron emitters, the motion of the positrons as well as the propagation and the detection of the annihilation photons. The steps of the modelling, the experimental validation and clinical implementation are presented.

Carbon↗
PubMed2006

X-ray imaging optimization using virtual phantoms and computerized observer modelling.

This study develops and demonstrates a realistic x-ray imaging simulator with computerized observers to maximize lesion detectability and minimize patient exposure. A software package, ViPRIS, incorporating two computational patient phantoms, has been developed for simulating x-ray radiographic images. A tomographic phantom, VIP-Man, constructed from Visible Human anatomical colour images is used to simulate the scattered portion using the ESGnrc Monte Carlo code. The primary portion of an x-ray image is simulated using the projection ray-tracing method through the Visible Human CT data set. To produce a realistic image, the software simulates quantum noise, blurring effects, lesions, detector absorption efficiency and other imaging artefacts. The primary and scattered portions of an x-ray chest image are combined to form a final image for computerized observer studies and image quality analysis. Absorbed doses in organs and tissues of the segmented VIP-Man phantom were also obtained from the Monte Carlo simulations. Approximately 25,000 simulated images and 2,500,000 data files were analysed using computerized observers. Hotelling and Laguerre-Gauss Hotelling observers are used to perform various lesion detection tasks. Several model observer tasks were used including SKE/BKE, MAFC and SKEV. The energy levels and fluence at the minimum dose required to detect a small lesion were determined with respect to lesion size, location and system parameters.

Computer Simulation↗
PubMed2004

The effect of the Family Case Management Program on 1996 birth outcomes in Illinois.

OBJECTIVES: The purpose of this study was to determine if birth outcomes for Medicaid recipients were improved with participation in the Illinois Family Case Management Program. METHODS: Health program data files were linked with the 1996 Illinois Vital Records linked birth-death certificate file. Logistic regression was used to characterize the variation in birth outcomes as a function of Family Case Management participation while statistically controlling for measurable factors found to be confounders. RESULTS: Results of the logistic regression analysis show that women who participated in the Family Care Management Program were significantly less likely to give birth to very low birth weight infants (odds ratio [OR] = 0.86, 95% confidence interval [CI] = 0.75, 0.99) and low birth weight infants (OR = 0.83, CI = 0.79, 0.89). For infant mortality, however, the adjusted OR (OR = 0.98, CI = 0.82, 1.17), although under 1, was not statistically significant. CONCLUSIONS: These results suggest that the Family Case Management Program may be effective in reducing very low birth weight and low birth weight rates among infants born to low-income women.

Adult↗
PubMed2005

The extended Kalman filter for continuous glucose monitoring.

Glucose monitoring is a problem with evolving solutions using sensors and data processing techniques that are continually improving. This paper presents the development and application of the extended Kalman filter to the problem of real-time estimation of blood glucose levels and is consistent with sensors based on optical, electrical, or chemical processes. The structure of the extended Kalman filter provides the capability to systematically accommodate new information as it develops. This flexibility and the potential for performance improvement are demonstrated by processing patient data files generated using the Medtronic (Northridge, CA) MiniMed continuous glucose monitoring system (CGMS).

Algorithms↗
PubMed2004

Spectral quality assessment for high-throughput tandem mass spectrometry proteomics.

Current techniques in tandem mass spectrometric analyses of cellular protein contents often produce thousands to tens of thousands of spectra per experiment. This study introduces a new algorithm, named SPEQUAL, which is aimed at automated tandem mass spectral quality assessment. The quality of a given spectrum can be evaluated from three basic components: (i) charge state differentiation, (ii) total signal intensity, and (iii) signal-to-noise estimates. The differentiation between single and multiple precursor charge states (i) provides a binary score for a given spectrum. Components (ii) and (iii) provide partial scores which are subsequently summarized and multiplied by the first score. SPEQUAL was applied to over 10,000 data files derived from almost 3,000 tandem mass spectra, and the results (final cumulative scores) were manually verified. SPEQUAL's performance was determined to have high sensitivity and specificity and low error rates for both spectral quality estimates in general and precursor charge state differentiation in particular. Each of the partial scores is controlled by adjustable thresholds to fine-tune SPEQUAL's performance for different analysis pipelines and instrumentation. This spectral quality assessment tool is intended to act in an advisory role to the researcher, assisting in filtration of thousands of spectra typically produced by high throughput tandem mass spectrometric proteome analyses. Lastly, SPEQUAL was implemented as Java GUI-based and command-line-based interfaces freely available for both academic and industrial researchers.

Mass Spectrometry↗
PubMed1980

Pathology accessioning and retrieval system with encoding by computer (PARSEC). A microcomputer-based system for anatomic pathology featuring automated SNOP coding and multiple administrative functions.

A pathology accessioning and retrieval system with encoding by computer (PARSEC) has been developed, employing a relatively inexpensive microcomputer. PARSEC performs a variety of administrative functions for anatomic pathology, including accessioning of surgical specimens, storage of patient demographic information, editing, retrieval, and archiving of patient data, as well as CAP (college of American Pathologists) workload units, billing, and inventory functions for histopathology. In addition, appropriate gross and microscopic descriptions and pathologic diagnoses can be entered into the system by a text editor. Automatic assignment of SNOP (Systematized Nomenclature of Pathology) codes, is accomplished via an online SNOP lexicon, allowing the ultimate generation of completed surgical pathology reports. The data base management system employed makes optimum use of disk storage space, while permitting rapid data retrieval. Data file maintenance is automatically accomplished by the system, requiring no user intervention.

Computers↗
PubMed1981

Microcomputer reporting and information system for microbiology.

A computerized reporting and information system for microbiology employing a relatively inexpensive microcomputer is described. A comprehensive approach to accessioning and result entry for microbiology is presented. A daily laboratory worklist is generated for each work area, providing the responsible technologist with information on previously processed specimens. Manipulation of patient and specimen information permits the performance of various functions, including the generation of billing reports, workload statistics, quality-control summaries, epidemiologic surveys, and cumulative reports. The employment of many user-definable data lexicons allows optimal use of disk space while affording rapid information retrieval. Data file maintenance is automatically accomplished by the system, requiring no user intervention.

Computers↗
PubMed2002

Validity of self-rated health among Latino(a)s.

The authors investigated whether self-rated health (SRH) had differential mortality risks for Latino(a) adults of various acculturation statuses living in the United States. They used cumulative National Health Interview Survey data from 1989 to 1994 (n = 37,713) linked with the National Health Interview Survey Multiple Cause of Death data files (1,364 deaths) that match records from the National Death Index through 1997. The authors specified survival models to estimate the effect of SRH on mortality and further stratified their model by birth and duration in the United States as proxies for acculturation. These estimates were compared across strata. Poor SRH was found to be a weaker predictor of subsequent mortality risk among the less acculturated, although the overall risk among the aggregated sample is similar to the risk reported in previous studies. The relation between poor SRH and mortality risk increases with United States acculturation among Latinos. While poor SRH was significantly associated with short-term mortality among the least acculturated, this association did not persist beyond 2-year mortality risk. Health researchers wishing to use SRH to assess the physical health of multiethnic populations should at least control for levels of acculturation among respondents.

Acculturation↗