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 469 records · Page 26Linked to original sources
PubMed1988

An analysis of noise-induced hearing loss in Army helicopter pilots.

Hearing loss in the aviation environment has been attributed to a variety of factors ranging from aircraft noise exposure to the aging process. Consequently, this study was conducted to determine the relative contribution of age, total flight hours, type of aircraft, and use of hearing protection to hearing loss in U.S. Army aviators. Information from a survey of the aviators in an aviation brigade was combined with audiometric records to create the data file. The final study group, 83% of the unit aviators, was evaluated for hearing loss using two criteria: 1) existing U.S. army standards, and 2) four empirical categories of significant threshold shift. Data analysis suggests that hearing loss is primarily a function of noise exposure as measured by total flight hours. Age was found to be a less significant factor; aircraft type had no significant effect. The results indicate that combination hearing protection appears to significantly lower the risk of hearing loss.

Aerospace Medicine↗
PubMed1997

Inflammatory pseudotumor of spleen. Report of two cases and literature review.

OBJECTIVE: We report two new cases of inflammatory pseudotumor of the spleen and review the cases reported to date. We discuss the diagnostic value of the clinical manifestations, the modern image technics and the laboratory data and conclude that only pathological and immunohistochemical studies allow a reliable diagnosis of this disease. DATA SOURCES: We have obtained the cases for the review through a computer search with the system SilverPlatter 3.11 (SilverPlatter Software Copyright NU 1992). The new cases have been obtained from our files. DATA SYNTHESIS: 53% were random findings (47% in the workup of another disease and 5% at autopsy). In the remaining cases, the clinical signs were not specific and none of the image technics could establish diagnosis. Neither fine needle aspiration nor laboratory data rendered conclusive results. Only pathological and immunohistochemical study after splenectomy allowed diagnosis. The clinical signs disappeared in all the cases following splenectomy and none of the patients have had recurrences. CONCLUSIONS: Inflammatory pseudotumor is a benign disease of unknown etiology and pathogenesis. It consists of solitary or multiple tumors that can affect virtually any organ. Clinical signs are non-specific. This lesion can render diagnostic problems with neoplasms of the lymphoreticular system. Splenectomy is diagnostic and curative.

Aged↗
PubMed2000

Umbilical artery catheters in the newborn: effects of catheter design (end vs side hole).

BACKGROUND: This section is under preparation and will be included in the next issue. OBJECTIVES: To determine whether the design of an umbilical arterial catheter influences the frequency of ischemic events, aortic thrombosis, intraventricular hemorrhage, mortality or necrotising enterocolitis in newborn infants. SEARCH STRATEGY: Randomized and quasi randomized controlled trials of umbilical catheterization use were obtained from the following sources: 1. Effective Care of the Newborn Infant, edited by JC Sinclair and MB Bracken. 2. Medline Search using Melvyl Medline Plus and the keyword headings 'Umbilic#', 'Catheter#' and subject heading 'Infant, Newborn' 3. Search of personal data files SELECTION CRITERIA: Randomized trials in newborn infants of any birthweight or gestation. Comparison of end hole catheters with side hole catheters. Clinically important end points such as ischemic events or aortic thrombosis. DATA COLLECTION AND ANALYSIS: There appears to be only a single trial which has addressed this issue (Wesstrom 1979). MAIN RESULTS: End hole catheters are associated with a much decreased risk of aortic thrombosis compared to side hole catheters. RR = 0.27 (95% CI 0.11, 0.67) REVIEWER'S CONCLUSIONS: Side hole catheters should be avoided for umbilical arterial catheterisation in the newborn.

Catheterization↗
PubMed1994

A multidimensional spectrophotometer for monitoring thermal unfolding transitions of macromolecules.

We describe a multidimensional spectrometer that is capable of (nearly) simultaneous measurement of circular dichroism, steady-state fluorescence, and absorbance values on the same sample in a standard 1 x 1 cm cuvette. With a computer controlled thermoelectric cell holder, this instrument is capable of measuring the above types of spectral data at various wavelengths as a function of temperature. We have developed software to control the various acquisition functions and to convert the data files to a format appropriate for use with the nonlinear least squares program, NONLIN (Johnson and Frasier, 1985). We have tested various features of this instrument and we have applied this instrument and data analysis procedure to study the thermal unfolding of ribonuclease A, under conditions were the unfolding of this protein involves an intermediate state.

Biophysical Phenomena↗
PubMed1995

HLA -A, -B, -DR haplotype frequencies in France--implications for recruitment of potential bone marrow donors.

We have undertaken a study of the haplotypes among French potential bone marrow donors in order to define the geographical regions of France with the maximum of polymorphism and also to develop a strategy for optimal donor recruitment. A maximum likelihood estimator was used to calculate haplotype frequencies and their support limits for each region and for the whole of France. The observed differences between the regions were statistically significant. For each region, the minimum number of haplotypes necessary to explain 50% of the total frequency was calculated and compared with the equivalent values, and confidence intervals, obtained by repeated random samplings from the overall file. This approach shows that some regions (e.g., Provence) appear to be richer in terms of the numbers of haplotypes observed, and others (e.g., Bretagne) poorer. In the latter case, however, the frequencies of the most common haplotypes are greater. The haplotype frequencies of the whole sample were used to calculate the probability of finding a match for the next potential recipient for given sizes of the donor file, assuming random selection of donors. They were also used to calculate expected numbers of the major phenotypes, assuming Hardy-Weinberg equilibrium, and these were compared with those observed in the real data file. In this way, a large number of under-represented and nonrepresented phenotypes were identified. For each of these phenotypes, the most probable haplotypes and the regions in which these have the greatest frequencies have been identified. A search for donors with such particular phenotypes would be much more fruitful if directed towards these regions.

Alleles↗
PubMed1994

Improving report turnaround time: an integrated method using data from a radiology information system.

OBJECTIVE: In the face of a changing health care system and increased competition, radiology departments need to become more efficient. One measurement of efficiency is promptness in producing a final report. Many large radiology centers have radiology information systems (RIS) that track work flow, collecting tremendous amounts of data. Most, however, lack an appropriate analytic mechanism. We have developed an integrated system that allows continual monitoring of radiology work flow and thus of opportunities to apply interventions. This system can form an important component of the quality management process in the radiology department. MATERIALS AND METHODS: In developing the system, we identified seven key steps in the work-flow process. When left to chance, these steps occur out of sequence and large delays occur. A scheme was devised to improve the sequencing of the work flow by using the data collected from the RIS, sorted by radiology division and patient type. Biweekly, the appropriate data file is transferred to each division for analysis, via the department's computer network. A one-step process follows, using desktop Macintosh computers and a custom program written in Microsoft Excel. Extracted data are quickly converted into a tailored division summary, and a report is automatically generated. RESULTS: The result summary format is uniform throughout the department, allowing ease of review at divisional and departmental meetings. Problems can be immediately localized to a specific step in the work-flow process. Automation of much of the system allows continual, near-real-time review of work flow. Using this approach, we have seen a sustained reduction of average report turnaround time. CONCLUSION: This system allows continual monitoring of work flow. It is largely automated and lends itself well to inclusion in the quality management program of any radiology department.

Medical Records Systems, Computerized↗
PubMed2001

Comparability of cause of death between ICD-9 and ICD-10: preliminary estimates.

OBJECTIVES: This report presents preliminary results describing the effects of implementing the Tenth Revision of the International Classification of Diseases (ICD-10) on mortality statistics for selected causes of death effective with deaths occurring in the United States in 1999. The report also describes major features of the Tenth Revision (ICD-10), including changes from the Ninth Revision (ICD-9) in classification and rules for selecting underlying causes of death. Application of comparability ratios is also discussed. METHODS: The report is based on cause-of-death information from a large sample of 1996 death certificates filed in the 50 States and the District of Columbia. Cause-of-death information in the sample includes underlying cause of death classified by both ICD-9 and ICD-10. Because the data file on which comparability information is derived is incomplete, results are preliminary. RESULTS: Preliminary comparability ratios by cause of death presented in this report indicate the extent of discontinuities in cause-of-death trends from 1998 through 1999 resulting from implementing ICD-10. For some leading causes (e.g., Septicemia, Influenza and pneumonia, Alzheimer's disease, and Nephritis, nephrotic syndrome and nephrosis), the discontinuity in trend is substantial. The ranking of leading causes of death is also substantially affected for some causes of death. CONCLUSIONS: Results of this study, although preliminary, are essential to analyzing trends in mortality between ICD-9 and ICD-10. In particular, the results provide a means for interpreting changes between 1998, which is the last year in which ICD-9 was used, and 1999, the year in which ICD-10 was implemented for mortality in the United States.

Cause of Death↗
PubMed2004

Quantification methodology for peripheral quantitative computed tomography (PQCT) data using public domain software.

OBJECTIVE: To develop a method for viewing, processing and acquiring 3-dimensional volumetric data from existing ovine spinal peripheral quantitative computed tomography (PQCT) scans of posterior lateral fusion. DESIGN: An image processing development study. BACKGROUND: Existing medical image viewing software can be expensive and difficult to adapt to meet specific research needs. The goals of this study were to produce volume rendering of PQCT scans through processing, masking, and segmentation using public domain software with established source code. METHODS: Raw data files (DICOM format) of 32 PQCT scans from animals receiving spine fusion were obtained. Metal hardware was removed from the images by masks and image segmentation. Calculation of bone macro-architecture volumetric data was performed on right and left sides of spines to quantify fusion volume in normalized segments between transverse processes. RESULTS: Images were acquired and opened. Application of image processing techniques made it possible to remove surgical hardware from original images with minimal loss of original PQCT data. Volumes were calculated and normalized to gray-scale of total bone throughout individual selected segments. CONCLUSION: Using public domain software is a cost effective means to view, process, and manipulate PQCT data. Bone macro-architecture can provide quantitative volumetric contributions to ascertain the role of structure on mechanical function.

Algorithms↗
PubMed1985

An algorithm to count the number of repeated patient data entries with B tree.

An algorithm to obtain the number of different values that appear a specified number of times in a given data field of a given data file is presented. Basically, a well-known B-tree structure is employed in this study. Some modifications were made to the basic B-tree algorithm. The first step of the modifications is to allow a data item whose values are not necessary distinct from one record to another to be used as a primary key. When a key value is inserted, the number of previous appearances is counted. At the end of all the insertions, the number of key values which are unique in the tree, the number of key values which appear twice, three times, and so forth are obtained. This algorithm is especially powerful for a large size file in disk storage.

Computers↗
PubMed1984

Risk of skin tumors in psoralen- and ultraviolet A-treated patients.

From 1973 to 1981, the clinical data of 1,136 patients with psoriasis and another 1,210 with various skin tumors were accessioned with the aid of computerized data files. Skin tumors and psoriasis occurred in 48 patients. After psoralen plus 320-400 nm UV (PUVA) therapy for psoriasis was introduced in 1976, 381 patients with this disease were treated. Follow-up data revealed no change in the tumor incidence rate after this treatment began. Age-related calculations of the relative probabilities for the presence of skin cancer in patients with psoriasis after PUVA revealed a grossly normal pattern (which appeared to be unaffected by PUVA). We observed a skin tumor in 2 patients 5 years after PUVA therapy.

Adult↗
PubMed2003

Behavioral data management using Visual Basics for Applications to automate data capture and analysis.

Many researchers are familiar with the spreadsheet capabilities of Microsoft Excel, but have never explored using customized VISUAL BASIC FOR APPLICATIONS (VBA) macros embedded in the program. At the United States Army Medical Research Institute of Chemical Defense (USAMRICD), the implementation of VBA program code to carry out repetitive operations has resulted in a tremendous savings in both the time and manpower required to reliably capture, analyze, and plot data from research protocols. A set of "template" workbooks was developed and is used to organize data from different types of studies. At the heart of the concept is a "setup information" worksheet onto which the user enters information about the study (i.e. the number of subjects, groups, graphs). Clicking a control button on this worksheet launches the VBA code that creates worksheets for each subject, group and chart specified. A "pairmatch" function allows the user to create groups either randomly or by pair matching based on user-specified variables. Controls are provided that run VBA program code to parse subject data files into the proper worksheets and perform group averages. Charts are updated automatically whenever group averages change so that the researcher always has an up-to-date plot available. The ability to reformat the captured data onto a "statistical output" worksheet allows data to be imported easily to statistical software packages. The concept is being used for several different types of studies at USAMRICD and has significantly reduced not only amount of time spent on data management, but also the number of data entry errors. Readers interested in acquiring an electronic copy of the startle workbook example, which contains the complete VBA code, should send the request to the authors at reseco@erols.com or maurice.sipos@us.army.mil.

Acoustic Stimulation↗
PubMed2001

Cytochrome P450 database.

This paper describes a specialized database dedicated exclusively to the cytochrome P450 superfamily. The system provides the impression of superfamily's nomenclature and describes structure and function of different P450 enzymes. Information on P450-catalyzed reactions, substrate preferences, peculiarities of induction and inhibition is available through the database management system. Also the source genes and appropriate translated proteins can be retrieved together with corresponding literature references. Developed programming solution provides the flexible interface for browsing, searching, grouping and reporting the information. Local version of database manager and required data files are distributed on a compact disk. Besides, there is a network version of the software available on Internet. The network version implies the original mechanism, which is useful for the permanent online extension of the data scope.

Catalysis↗
PubMed1995

Information, intelligence, and interface: the pillars of a successful medical information system.

This paper addresses three key issues facing developers of clinical and/or research medical information systems. 1. INFORMATION. The basic function of every database is to store information about the phenomenon under investigation. There are many ways to organize information in a computer; however only a few will prove optimal for any real life situation. Computer Science theory has developed several approaches to database structure, with relational theory leading in popularity among end users [8]. Strict conformance to the rules of relational database design rewards the user with consistent data and flexible access to that data. A properly defined database structure minimizes redundancy i.e.,multiple storage of the same information. Redundancy introduces problems when updating a database, since the repeated value has to be updated in all locations--missing even a single value corrupts the whole database, and incorrect reports are produced [8]. To avoid such problems, relational theory offers a formal mechanism for determining the number and content of data files. These files not only preserve the conceptual schema of the application domain, but allow a virtually unlimited number of reports to be efficiently generated. 2. INTELLIGENCE. Flexible access enables the user to harvest additional value from collected data. This value is usually gained via reports defined at the time of database design. Although these reports are indispensable, with proper tools more information can be extracted from the database. For example, machine learning, a sub-discipline of artificial intelligence, has been successfully used to extract knowledge from databases of varying size by uncovering a correlation among fields and records[1-6, 9]. This knowledge, represented in the form of decision trees, production rules, and probabilistic networks, clearly adds a flavor of intelligence to the data collection and manipulation system. 3. INTERFACE. Despite the obvious importance of collecting data and extracting knowledge, current systems often impede these processes. Problems stem from the lack of user friendliness and functionality. To overcome these problems, several features of a successful human-computer interface have been identified [7], including the following "golden" rules of dialog design [7]: consistency, use of shortcuts for frequent users, informative feedback, organized sequence of actions, simple error handling, easy reversal of actions, user-oriented focus of control, and reduced short-term memory load. To this list of rules, we added visual representation of both data and query results, since our experience has demonstrated that users react much more positively to visual rather than textual information. In our design of the Orthopaedic Trauma Registry--under development at the Carolinas Medical Center--we have made every effort to follow the above rules. The results were rewarding--the end users actually not only want to use the product, but also to participate in its development.

Artificial Intelligence↗
PubMed2006

Exploring changes in middle-school student lunch consumption after local school food service policy modifications.

OBJECTIVE: This study assessed the impact of changes in school food policy on student lunch consumption in middle schools. METHODS: Two years of lunch food records were collected from students at three middle schools in the Houston, Texas area. During the first year, no changes occurred in the school food environment. After that school year was completed, chips and dessert foods were removed from the snack bars of all schools by the Food Service Director. Students recorded the amount and source of food and beverage items consumed. Point-of-service purchase machines provided a day-by-day electronic data file with food and beverage purchases from the snack bars during the 2-year period. Independent t-tests and time series analyses were used to document the impact of the policy change on consumption and sales data between the two years. RESULTS: In general, student consumption of sweetened beverages declined and milk, calcium, vitamin A, saturated fat and sodium increased after the policy change. Snack chips consumption from the snack bar declined in year 2; however, consumption of snack chips and candy from vending increased and the number of vending machines in study schools doubled during the study period. Ice cream sales increased significantly in year 2. CONCLUSIONS: Policy changes on foods sold in schools can result in changes in student consumption from the targeted environments. However, if all environments do not make similar changes, compensation may occur.

Adolescent↗
PubMed1996

Childhood family problems and current psychiatric problems among young violent and property offenders.

OBJECTIVE: The main objective was to examine whether young property and violent offenders would differ from each other in the prevalence of childhood abuse and neglect experiences, prevalence of various early family problems, and prevalence of disruptive behavior disorders, depression, and substance use. METHOD: Childhood abuse and neglect assessments and family problems were based on interview, questionnaire, and file data. Psychiatric diagnoses were made on the basis of a structured clinical interview. RESULTS: There were no statistically significant differences in the prevalence of childhood physical or psychological abuse, or neglect between the groups. According to the files, physical abuse was experienced by 57.5% of the violent offenders compared with 37% of the property offenders (p = .10). The prevalence rates of family problems were not different in the groups. Seventy-one percent of the violent group abused street drugs compared with 51% of the property group (p < .05), but the groups did not differ in disruptive behavior disorders, alcohol abuse/dependence, or depression. CONCLUSIONS: The property and violent offenders were surprisingly similar to each other in childhood experiences, family problems, and psychiatric diagnoses. The prevalence of childhood family and psychiatric problems was high in both groups.

Adolescent↗
PubMed2006

The utility of an automated electronic system to monitor and audit transfusion practice.

BACKGROUND AND OBJECTIVES: Transfusion laboratories with transfusion committees have a responsibility to monitor transfusion practice and generate improvements in clinical decision-making and red cell usage. However, this can be problematic and expensive because data cannot be readily extracted from most laboratory information systems. To overcome this problem, we developed and introduced a system to electronically extract and collate extensive amounts of data from two laboratory information systems and to link it with ICD10 clinical codes in a new database using standard information technology. MATERIALS AND METHODS: Three data files were generated from two laboratory information systems, ULTRA (version 3.2) and TM, using standard information technology scripts. These were patient pre- and post-transfusion haemoglobin, blood group and antibody screen, and cross match and transfusion data. These data together with ICD10 codes for surgical cases were imported into an MS ACCESS database and linked by means of a unique laboratory number. Queries were then run to extract the relevant information and processed in Microsoft Excel for graphical presentation. We assessed the utility of this data extraction system to audit transfusion practice in a 600-bed adult tertiary hospital over an 18-month period. RESULTS: A total of 52 MB of data were extracted from the two laboratory information systems for the 18-month period and together with 2.0 MB theatre ICD10 data enabled case-specific transfusion information to be generated. The audit evaluated 15,992 blood group and antibody screens, 25,344 cross-matched red cell units and 15,455 transfused red cell units. Data evaluated included cross-matched to transfusion ratios and pre- and post-transfusion haemoglobin levels for a range of clinical diagnoses. Data showed significant differences between clinical units and by ICD10 code. CONCLUSION: This method to electronically extract large amounts of data and linkage with clinical databases has provided a powerful and sustainable tool for monitoring transfusion practice. It has been successfully used to identify areas requiring education, training and clinical guidance and allows for comparison with national haemoglobin-based transfusion guidelines.

Adult↗
PubMed1999

Outcome following acute myocardial infarction: are differences among physician specialties the result of quality of care or case mix?

BACKGROUND: Studies to determine whether care by cardiologists improves the survival of patients with acute myocardial infarction (MI) have produced conflicting results, and it is not known what accounts for differences in patient outcome by physician specialty. OBJECTIVES: To evaluate whether cardiologists provide more recommended therapies to elderly patients with acute MI and, if so, to determine whether variations in processes of care account for differences in patient outcome. DESIGN: Retrospective cohort study using medical chart data and administrative data files. SETTING: All nonfederal acute care hospitals in California. PATIENTS: A cohort of 7663 Medicare beneficiaries 65 years and older directly admitted to the hospital with a confirmed acute MI from April 1994 to July 1995 with complete data regarding potential contraindications to recommended therapies. MAIN OUTCOME MEASURES: Percentage of "good" and "ideal" candidates for a given acute MI therapy who actually received that therapy, percentage who received exercise stress testing or coronary angiography, percentage who underwent revascularization, and 1-year mortality, stratified by specialty of the attending physician. RESULTS: During hospitalization, good candidates for aspirin were more likely to receive aspirin if they were treated by cardiologists (87%) than by medical subspecialists (73%; P<.001), general internists (84%; P = .003), or family practitioners (81%; P<.001). Cardiologists were also more likely to treat good candidates with thrombolytic therapy (51%) than were medical subspecialists (29%; P<.001), general internists (40%; P<.001), or family practitioners (27%; P<.001). Patients of cardiologists were 2- to 4-fold more likely to undergo a revascularization procedure. Despite these differences in utilization, we found similar 30-day mortality rates across physician specialties. However, 1-year mortality rates were greater for patients treated by medical subspecialists (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.6-2.3), general internists (OR, 1.4; 95% CI, 1.3-1.6), and family practitioners (OR, 1.7; 95% CI, 1.4-1.9) than for those treated by cardiologists. Adjusting for differences in patient and hospital characteristics markedly reduced the ORs for those treated by medical subspecialists (OR, 1.2; 95% CI, 0.9-1.4), general internists (OR, 1.1; 95% CI, 1.0-1.3), and family practitioners (OR, 1.3; 95% CI, 1.1-1.6), whereas further adjustment for medication use and revascularization procedures had little effect. CONCLUSIONS: Differences in the use of recommended therapies by physician specialty are generally small and do not explain differences in patient outcome. In comparison, differences among patients treated by physicians of various specialties (case mix) have a large impact on patient outcome and may account for the residual survival advantage of patients treated by cardiologists. With the exception of the in-hospital use of aspirin, recommended MI therapies are markedly underused, regardless of the specialty of the physician.

Aged↗
PubMed1985

Rat medulla oblongata. IV. Topographical distribution of catecholaminergic neurons with quantitative three-dimensional computer reconstruction.

We examined serial 40 micron vibratome, immunoperoxidase-stained sections of the medulla with tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH), and phenylethanolamine N-methyltransferase (PNMT) antisera followed by Nissl staining to locate catecholaminergic neurons in cytoarchitectonic regions followed by a three-dimensional (3D) computer reconstruction of these cell groups to determine their spatial organization. Overlay drawings of low and high power photomicrographs showing cell bodies and nuclear boundaries were entered into a digital computer storage system. Every section in the series was plotted to yield an accurate representation of regional densities of cells and location of nuclei, as revealed by two-dimensional plots of individual sections as well as three-dimensional plots of groups of sections. Data files were scanned in a number of ways to obtain total cell counts of TH-, DBH-, and PNMT-immunoreactive cells within a designated area or cell counts of only one type of immunoreactive cell. This combination of data manipulation produced the following results: (1) A1 group is a homogeneous population of noradrenergic neurons at levels caudal to the obex, and at the obex it is mixed with adrenergic cells. The dimensions of the A1 cell group are 1.3 X 2.7 mm, extending from -2.5 to +0.2. Part of this cell group lies in the lateral reticular nucleus. (2) A2 group is not purely noradrenergic as previously suspected. It is a very mixed cell group containing mainly dopaminergic neurons in the area postrema (periventricular region) and the dorsal motor nucleus of the vagus, mainly noradrenergic neurons in the medial subnucleus of the nucleus of the tractus solitarius (nTS), mainly adrenergic neurons in the dorsal strip and dorsal subnucleus of the nucleus of the tractus solitarius, and a mixture of all three catecholaminergic neurons in the other subnuclei of the nTS. The dimensions of this group are 0.4 X 3 mm extending from -2.7 to +0.3. (3) C1 group is a homogeneous population of adrenaline cells extending from +1 to +2.5 with dimensions of 1.5 X 1.5 mm and consisting of scattered neurons some of which occupy the gigantocellular reticular nucleus. (4) C2 group is a homogeneous population of adrenaline neurons extending from +1 to +3 with dimensions of 2.5 X 3 mm. Accurate visual imaging and quantitation of the spatial organization of medullary catecholaminergic neurons within the classical anatomical framework of cytoarchitecture provides an enhanced comprehension of the organization of this region of the central nervous system.

Animals↗