SEARCH · PubMed Health

Results for “Data Aggregation”

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 145 records · Page 8Linked to original sources

PubMed1994

An information model for medical events.

Information gathered during the healthcare process is lost when forced into rigidly structured record-oriented databases. By contrast, content can be difficult to manipulate if stored as unstructured text. Spurred by the requirements of electronic publishing, military procurement and the Internet, new robust standards for structuring documents have been developed and deployed. These standards can provide a foundation for a document-based Electronic Medical Record System. In order to fully exploit this added flexibility, an information model is necessary to define both the direct and contextual content of documents. Once context, as well as fact, are recorded in formal structures, inferential techniques can either selectively extract knowledge and data from documents or aggregate data to create summaries so that all interested and authorized parties have a better chance of meeting their information needs from a single, permanent data source.

Humans↗

PubMed2005

Bayesian spatio-temporal modelling of national milk-recording data of seasonal-calving New Zealand dairy herds.

A spatio-temporal analysis was undertaken with the aim of identifying the dynamics of herd mean individual cow SCCs (MICSCC) in seasonally calving New Zealand dairy herds. Two datasets were extracted from the Livestock Improvement Corporation's extensive national dairy recording database: (1) milk-recording data aggregated at the herd-level and (2) sales questionnaire data containing information on the size, location and infrastructure of each farm. A Bayesian spatio-temporal modelling approach was applied to the analysis. The data were aggregated by 10 km(2) grid cells and linear regression models were developed with spatially structured and unstructured random effects, a linear temporal trend random effect and spatial-temporal interactions for log-transformed median MISCC (ln(median MISCC)). Significant associations were found between ln(median MISCC) and milk yield, milk fat, milk protein, farm area and number of cups in the dairy. This led us to suggest that SCCs should be adjusted for volume and constituents prior to determining a threshold MISCC for identification of subclinical mastitis (SCM) problem herds. Part, or all, of the temporal trend in MISCC in the spatio-temporal model was accounted for by inclusion of yield and milk constituents as independent variables. This supports the hypothesis of a dilution effect with potential consequences for misdiagnosis of SCM, particularly in late lactation. Unmeasured covariates were similarly likely to be spatially structured and unstructured.

Animals↗

PubMed2004

Eformoterol n-of-1 trials in chronic obstructive pulmonary disease poorly reversible to salbutamol.

AIMS: Benefits of long acting beta 2 agonists are unclear for severe chronic obstructive pulmonary disease (COPD) patients with poor response to short acting bronchodilators. We aimed to evaluate 1) effects of eformoterol in such patients using a 'n-of-1' double crossover study design, and 2) aggregate data as a double-blind, double crossover randomized control trial. METHODS: Subjects with forced expiratory volume in one second (FEV1) < 60% predicted, and poor response to short acting bronchodilators were studied six times over 18 weeks. During that time they were prescribed four weeks of either eformoterol or placebo, followed by the alternate, and then a second crossover. Four-weekly measures included six minute walk distance (6MWD), FEV1, previous two weeks of symptoms, and chronic respiratory questionnaire (CRQ) including treatment goal items. RESULTS: Of 27 original subjects (21 male, mean age of 70 years, five smokers, mean prebronchodilator FEV1 36% predicted), one subject had clinically significant concordant improvement in the CRQ dyspnoea domain and 6MWD (by 51 metres), but not for other outcomes. There were no concordant improvements in any other subjects. Aggregate double crossover data analysis demonstrated no improvement in any outcome measures. CONCLUSIONS: The 'n-of-1' study design and aggregate data analysis demonstrated lack of benefit from eformoterol in COPD patients with poor response to short acting bronchodilators.

Adrenergic beta-Agonists↗

PubMed2001

Monitoring and ensuring safety during clinical research.

Increased numbers of clinical trials, many of which are large, multicenter, and sometimes international, and the marked shift of funding for clinical trials to industry have made apparent the inadequacy of mechanisms for protecting human subjects that were developed when clinical research was generally carried out on a small scale at single institutions. To address concerns regarding the protection of human subjects, a group of professionals with expertise in various aspects of clinical trials was assembled in May 2000. Participants described and evaluated the mechanisms by which clinical trials are monitored, focusing on adverse event reporting and the processes by which various parties with oversight responsibilities interact in the course of these trials. In this article, we describe the manner in which adverse event reporting might function to enhance safety and the role of data monitoring committees in using aggregate data from these reports, outline the problems that now exist for institutional review boards as they are faced with multiple adverse event reports from clinical trials while conducting continuing review, and offer recommendations for improving the current approach.

Clinical Trials as Topic↗

PubMed2003

Coding accuracy for endophthalmitis diagnosis and cataract procedures in Western Australia. The Endophthalmitis Population Study of Western Australia (EPSWA): second report.

As an initial phase of the Endophthalmitis Population Study of Western Australia (EPSWA), this paper reports the results from an intensive comparative validation of all possible surgery-related endophthalmitis cases identified for the period from 1980 to June 1999 from the Hospital Morbidity Data System (HMDS) of the WA Record Linkage Project with external sources. The external sources were the microbiology and anaesthetic databases from Royal Perth Hospital (where most of the cases of endophthalmitis were treated) and surgeon logbooks of two vitreoretinal surgeons treating endophthalmitis in Perth over the study period. As it was discovered that a large proportion of all cases coded with endophthalmitis did not have any ocular surgery, the validation also included a sample from these cases. The purpose of validating these cases was to ensure that our count of post-operative endophthalmitis had not excluded any cases whose surgery might not have been recorded in the HMDS database. It was also intended to provide an estimate of all miscoded endophthalmitis cases as a first step towards future improvement of coding accuracy. Since we suspected that phaco-emulsification was under-coded, we also examined a sample of cataract procedures. Of all surgery-related endophthalmitis cases coded in the HMDS, only 50.9% (274 of 538) were found to be valid cases. External sources identified 83 cases of endophthalmitis, 49 did not have endophthal-mitis codes but were in the HMDS file with an associated code. Of the remaining externally identified cases, 13 were missing altogether from the HMDS file, 7 of which were correctly coded in the notes while the other 6 were coded with associated codes, and 21 were diagnosed after the date the HMDS file was extracted. The validation of a random sample of the non-surgery-related cases coded with endophthalmitis suggested that the vast majority of them were miscoded (88%, 139 of 158 sampled from 1474 cases). The systematic coding errors reported in this paper may be attributed to both the clinical and the coding departments of the hospital. In any case, coding inaccuracy itself is a serious concern for data quality of any linked database systems and for epidemiological researchers using such data. The increased use of aggregated data in epidemiological research further underscores the importance of coding accuracy and thus data validation. The use of external sources for case identification and case validation are two ways of ensuring data completeness/quality and validity of results.

Cataract↗

PubMed2006

Understanding widely scattered traffic flows, the capacity drop, and platoons as effects of variance-driven time gaps.

We investigate the adaptation of the time headways in car-following models as a function of the local velocity variance, which is a measure of the inhomogeneity of traffic flow. We apply this mechanism to several car-following models and simulate traffic breakdowns in open systems with an on-ramp as bottleneck and in a closed ring road. Single-vehicle data and one-minute aggregated data generated by several virtual detectors show a semiquantitative agreement with microscopic and flow-density data from the Dutch freeway A9. This includes the observed distributions of the net time headways for free and congested traffic, the velocity variance as a function of density, and the fundamental diagram. The modal value of the time headway distribution is shifted by a factor of about 2 under congested conditions. Macroscopically, this corresponds to the capacity drop at the transition from free to congested traffic. The simulated fundamental diagram shows free, synchronized, and jammed traffic, and a wide scattering in the congested traffic regime. We explain this by a self-organized variance-driven process that leads to the spontaneous formation and decay of long-lived platoons even for a deterministic dynamics on a single lane.

Journal Article↗

PubMed1996

A longitudinal study of veterinary students and recent graduates. 1. Backgrounds, plans and subsequent employment.

OBJECTIVE: To examine factors that influence career choices by veterinary graduates. DESIGN: Longitudinal study. POPULATION: Students-77 female and 77 males-who began studying veterinary science at The University of Queensland in 1985 and 1986. PROCEDURE: Questionnaires were completed in the first and fifth year of the course, and in the second year after graduation. The data were arranged into an aggregated data set, then analysed using the SAS System for Windows. RESULTS: These students chose veterinary science, in many cases at an early age, because of their attitudes towards animals rather than advice from other people. Most had extensive experience with animals, and many gained this in cities rather than on farms. Between half and two-thirds of them looked forward to a career in private-practice when they were in first year. The proportion planning a career in private practice was highest for those who chose veterinary science before they were 12 years old. One-quarter of those in first year were undecided about what they would do after graduation. When they were surveyed in fifth year, most planned to enter mixed private practice at least initially. In fact, 59% entered mixed practice and 28% small animal practice. there were no significant relationships between prior experience with animals and either career plans or success in the job market. When asked in their second year after graduation, about half planned to continue in private practice over the longer term, and a quarter were undecided. CONCLUSIONS: The decision to study veterinary science is often made at a young age, and is influenced mainly by attitudes towards animals. The career path planned by the majority involves private practice, but for about a quarter the future is unclear, both when they enter the course and after they have worked as veterinarians.

Age Factors↗

PubMed2004

Health status and health services utilization among US Chinese, Asian Indian, Filipino, and other Asian/Pacific Islander Children.

OBJECTIVE: This study examines the health status and health services access and utilization characteristics of US Chinese, Asian Indian, Filipino, other Asian/Pacific Islander (API), and non-Hispanic white children by using nationally representative data. METHODS: We analyzed the aggregated data file from the National Health Interview Survey from 1997 to 2000 including 334 Chinese, 287 Asian Indian, 292 Filipino, 696 "other API," and 29,016 non-Hispanic white children <18 years old. Bivariate and multivariate analyses were conducted to examine the relationship between Asian ethnicities and dependent variables including components of health status, health services access, and utilization. RESULTS: Logistic regression reveals that all Asian American children were less likely to miss school because of illness or injury or have learning disabilities compared with non-Hispanic whites. Other APIs were less likely to be taking prescription medication for at least 3 months, and Asian Indian children were half as likely to have chronic conditions. Chinese, Filipino, and other API children were more likely to be without contact with a health professional within the past 12 months. Citizenship/nativity status, maternal education attainment, and poverty status were all significant independent risk factors for health care access and utilization. CONCLUSIONS: Asian ethnicities and being foreign-born are generally associated with more favorable health status measures such as school absence, learning disability, use of prescription medications, and chronic conditions. However, these attributes are negatively associated with health care access and utilization, suggesting the need for outreach to Asian immigrant populations to educate them on accessing the US health care system.

Adolescent↗

PubMed2003

TSN Database Australia, a new tool to monitor antimicrobial resistance in Australia.

An electronic network of Australian microbiology laboratories was established to monitor the emergence and occurrence of antimicrobial resistance among clinically relevant bacteria. It is believed that the data network collected approximately 42 per cent of all antibacterial susceptibility test results generated by Australian laboratories. The network comprised 94 hospitals and 9 private commercial laboratories. Selected data elements were extracted and electronically transmitted to a central location. Upon receipt, all data were first normalised and thereafter examined for errors. Duplicate results for the same patient were identified to prevent skewing of the data toward resistance. All data passing quality assessment was staged for release of a new database release that occurred monthly. Unusual test results were first validated prior to their inclusion into the database. Using an Internet-based query tool, individual institutions could query their own data, but could only query aggregated data for other regional or national analyses. Individual patient results could be examined nor could the results of any individual institution other than their own. As of March 2002, TSN Database Australia contained 14,648,752 test results, from 2,000,394 strains (453 different taxa) and 1,213,605 patients. Since the same database concept has been established in 10 other countries (United States of America, Europe, and Canada), observations made in Australia may be compared to those observed elsewhere in the world. This article will describe TSN in greater detail, describe the query tool and some of the analyses that are possible.

Anti-Bacterial Agents↗

PubMed2001

Nonlinear parameters estimation from sequential short time data series.

Procedures of nonlinear parameter estimation require large samples of data. In stationary physiological situations, usually short time series are available. The method of dynamics-dependent windowing and data aggregation procedure are proposed. This technique was tested on chaotic signal generated by Lorenz model and applied to investigate beat-to-beat control of the cardiovascular system in 10 healthy volunteers. Nonivasively recorded blood pressure, respiratory activity and blood oxygen saturation were digitized and saved for further off-line analysis. The experimental procedure consisted of 10 min control--C, 20 voluntary apneas 1 min each-A, interapnea 20 periods of 1 min spontaneous breathing--B, and 10 min free-breathing recovery--R. Respiration signal served as a reference for apnea and interapnea free-breathing identification period. Correlation dimension-CD, according to Grassberger and Procaccia, and recurrence plot strategy, according to Webber and Zbilut, were applied to check dynamical properties of the signals. Results of numerical experiment on Lorenz model, original and transformed by segmentation and aggregation, support our assumption of similarity of their dynamics. Error in CD and recurrence parameters estimation strongly depended on segment length and was about 5% for 600 to 1,200 data points. However, even for segments of 75 to 100 samples, it did not exceed 10% for all, but one, periodic testing signal. Segmentation and aggregation applied to interbeat interval (IBI) and total peripheral resistance (TPR) data showed that CD and recurrence variables estimated separately for apneic and interapneic period and those calculated for mixed (apneic and interapneic) intervals were different. Average CD and recurrence parameters of IBI and TPR for 10 subjects during apnea and interapnea intervals were significantly different than during control and recovery. The lowest CD (mean +/- S.D.) of 6.38 +/- 0.4, 5.62 +/- 0.2 and %recurrence 10.35 +/- 0.8, 6.62 +/- 0.6 (highest ratio 4.95 +/- 0.2, 5.13 +/- 0.3) were observed in apnea for IBI and TPR, respectively. Low values of the estimates computed for mixed periods may suggest the influence of slowly varying, quasiperiodic driving force due to experimental procedure regime. Signal dynamics-dependent windowing and data aggregation regardless of the sequence of data could be a practical solution for nonlinear analysis of very short repeatable time series.

Adult↗

PubMedDate not supplied

Accumulating evidence from independent studies: what we can win and what we can lose.

When asking 'what is known' about a drug or therapy or program at any time, both researchers and practitioners often confront more than a single study. Facing a variety of findings, where conflicts may outweigh agreement, how can a reviewer constructively approach the task? In this discussion, I will outline some questions that can only be answered by examining a group of independent studies. I will also discuss some pitfalls that sometimes swamp the benefits we can gain from synthesis. Most of these pitfalls are avoidable if anticipated early in a review. The benefits of a quantitative review include information about how to match a treatment with the most promising recipients; increasing the statistical power to detect a significant new treatment; telling us when 'contextual effects' are important; helping us to assess the stability and robustness of treatment effectiveness; and informing us when research finds are especially sensitive to investigators' research design. The pitfalls include aggregating data from studies on different populations; aggregating when there is more than one underlying measure of central tendency; and emphasizing an average outcome when partitioning variance gives far more useful information.

Bibliographies as Topic↗

PubMed1983

Computerized medical records. A new resource for clinical decision making.

A computerized medical record changes the way a clinician practices medicine by presenting data about patients in multiple organized formats. A computerized record can be used to make it more difficult to overlook important findings. The computer can improve communication by informing both the patient and referring physicians of new data as they become available. Computer graphics or algorithms can be used to emphasize subtle trends. A computer data base can be used to aggregate data about selected patients to provide information about the natural history of disease and effect of treatment.

Computers↗

PubMed2002

Why has postal prescriber feedback no substantial impact on general practitioners' prescribing practice? A qualitative study.

OBJECTIVE: To better understand the reasons for lack of impact of sending feedback on prescribing pattern to general practitioners (GPs). METHODS: Semi-structured interviews with GPs who had all participated in intervention studies addressing effects of prescriber feedback. Interviews were audiotaped and fully transcribed. Transcripts were studied repeatedly and coded into categories in order to produce meaningful patterns. RESULTS: None of the GPs believed they altered prescribing practice after they received prescriber feedback. Unsolicited prescriber feedback was perceived as violating the GPs' autonomy. The GPs wanted to decide for themselves what data should be sent to them. Aggregated data were difficult to interpret, and GPs did not regard it as a problem that their practice pattern deviated from that of other practices. There was a mistrust of the validity of data, and the GPs wanted to be able to identify the patients with a need for optimised therapy directly from the information provided in the prescriber feedback. In addition they wanted advice on how to optimise therapy. CONCLUSION: Postal prescriber feedback (not revealing the patients' identities) is not effective because it does not motivate GPs to change nor does it address the barriers to change. Prescriber feedback requested by the GPs may be more effective, however, if it includes identities of inappropriately treated patients combined with relevant advice on how to optimise prescribing.

Attitude of Health Personnel↗

PubMed2025

Utility of genome sequencing and group-enrichment to support splice variant interpretation in Marfan syndrome.

PURPOSE: To quantify the impact of noncanonical FBN1 splice site variants in undiagnosed Marfan syndrome (MFS), a connective tissue disorder associated with skeletal abnormalities and familial thoracic aortic aneurysm disease (FTAAD). METHODS: A systematic analysis of ultrarare FBN1 variants was performed using genome sequencing data from the 100,000 Genomes Project. Variants were annotated with SpliceAI and the significance of enrichment among individuals with FTAAD was assessed using Fisher's exact test. Experimental validation used RNA sequencing, reverse transcriptase polymerase chain reaction, minigene constructs, and replication analysis was with data from UK Biobank. RESULTS: Using aggregate data for 78,195 individuals, we identified 13,864 singleton single-nucleotide variants in FBN1 of which 21 were predicted to affect splicing (SpliceAI > 0.5). Incidence of candidate splice variants in individuals recruited with FTAAD (9/703) was significantly elevated compared with that seen in non-FTAAD participants (12/77,492; odds ratio = 84, P = 9.7 × 10-14). Additional analysis uncovered a further 14 families harboring 11 different FBN1 splice variants. A total of 20 candidate splice variants in 23 families were identified, of which 70% lay beyond the ±8 splice regions. RNA testing confirmed the predicted splice aberration in 16 of 20 and for 9 of 20, pseudoexonization was the likely splicing anomaly. CONCLUSION: Our findings indicate that noncanonical splice variants may account for approximately 3% of families with undiagnosed FTAAD, highlighting the importance of incorporating analysis of introns and confirmatory RNA testing into genetic testing for Marfan syndrome.

Humans↗

PubMed2002

The Eden Alternative: findings after 1 year of implementation.

BACKGROUND: This study examines the effects of the Eden Alternative (EA), a systematic introduction of pets, plants, and children into a nursing home, on the quality of life of nursing home residents. METHODS: Two nursing homes run by the same organization participated. The study site began implementing the EA in November 1998. The control site continued traditional care. Patient-level data from the Minimum Data Set (MDS), Version 2.0, and aggregate data based on staff reports were used to compare the residents at the two sites in terms of cognition, survival, immune function, functional status, and cost of care after 1 year. RESULTS: After adjusting for baseline differences, follow-up MDS data indicated that the Eden site had significantly greater proportions of residents who had fallen within the past 30 days (p =.011) and residents who were experiencing nutritional problems (p <.001). Staff report data indicated that, during the study period, the Eden site had significantly higher rates of residents requiring skilled nursing and hypnotic prescriptions, and more staff terminations and new hires. The control site had significantly higher rates of residents requiring anxiolytic prescriptions. CONCLUSIONS: The findings from this study indicate no beneficial effects of the EA in terms of cognition, functional status, survival, infection rate, or cost of care after 1 year. However, qualitative observations at the Eden site indicated that the change was positive for many staff as well as residents, suggesting that it may take longer than a year to demonstrate improvements attributable to the EA.

Aged↗

PubMed2001

DIABCARE Quality Network in Europe--a model for quality management in chronic diseases.

The DIABCARE Q-Net project developed a complete and integrated information technology system to monitor diabetes care, according to the gold standards of the St Vincent Declaration Action Program. This is the first Telematic platform for standardized documentation on medical quality and evaluation across Europe, which will serve as a model for other chronic diseases. Quality development starts from the comparison of diabetes services, based on the key data on diabetes care in the basic information sheet. This is a 141 field form, which is to be completed once a year for each patient under the care of the diabetes team. The system performs an analysis of the local data and compares the data with peer teams by means of telecommunication of anonymous data. These data are collected regionally. At the next level these regional data are compared on a national basis across Europe using dedicated communication lines. National data can be compared transnationally by the use of the Internet and the DIABCARE benchmarking servers. These different lines are used according to the necessary security standards. Medical data are transferred via dedicated lines, aggregated data via the Internet. The architecture follows the open-platform concept in order to allow for heterogeneous technical environments. Already at the start of the project, the necessity for expanding the quality approach to telemedicine methodology was identified and included. For each level, specific programs are available to improve the performance of diabetes care delivery: DIABCARE data as client and DIABCARE server as regional and DIABCARE 'international server' as transnational server. Functioning pilots were established across all levels. The clients have been linked to the servers on a routine basis. According to the open architecture design, the various countries decided on different systems at the entry point: full system--Portugal; fax systems--Italy, Bavaria; implementation into doctor's office systems--Norway; paper forms and chip cards--France. This system can improve the local, regional and national diabetes care. Initiatives in several countries proved the feasibility of the system. The most extensive use, from Portugal, will be reported later in this paper. The exploitation of the DIABCARE Q-Net system will be performed with the DIABCARE International European Economic Interest Grouping as a co-ordinator and several commercial companies as contractors to market the products inside the system. The key project participants are: DIABCARE Office EURO, DIABCARE Portugal, DIABCARE France, DIABCARE Bavaria, DIABCARE UK, DIABCARE Netherlands, DIABCARE Norway, DIABCARE Italy, DIABCARE Sweden, DIABCARE Austria, DIABCARE Spain, GSF Research Centre for Health and Environment, FAST Research Institute for Applied Software Technology, Tromsø University Hospital, Stavanger Technical College, Technical University of Ilmenau, World Health Organisation (WHO), Regional Office for Europe.

Benchmarking↗

PubMed1998

Consumption of fruit and wine and the decline in cerebrovascular disease mortality in Spain (1975-1993).

BACKGROUND AND PURPOSE: This study examines the changes in provincial distribution of cerebrovascular disease (CVD) mortality and its socioeconomic and lifestyle risk factors to identify those factors that have most greatly contributed to the decline in CVD mortality in Spain during the period 1975-1993. METHODS: We performed a study using data aggregated at a provincial level. Mortality data were taken from official vital statistics, while data on risk factors were obtained from surveys of representative large Spanish population samples. Correlation and multiple linear regression analyses were performed on percent changes in age-standardized CVD mortality from 1975-1979 to 1989-1993 and its potential determinants during the period 1964-1980. RESULTS: CVD mortality was higher in the southern and eastern (Mediterranean coast) provinces in 1975-1979 and again in 1989-1993. Between these periods there was a 55% decline in CVD mortality, which affected all provinces but was greater in those with a lower CVD mortality (r = -0.31, P = 0.03). The 1964-1980 period witnessed an increase in the intake of most foodstuffs and all types of fats. However, there was a decrease in the consumption of vegetables and legumes and in the proportion of illiteracy among the population older than 45 years. The greatest increase in fruit and fish consumption and the greatest decrease in illiteracy were registered by Spain's northernmost provinces, the same provinces that recorded the greatest decline in CVD mortality. Changes in fruit, wine, and fish intake accounted for 22% of the variation in the decline in CVD mortality. The increase in fruit consumption and decrease in wine consumption showed a statistically significant relationship (P < or = 0.04) with the decline in CVD mortality. CONCLUSIONS: The increase in fruit and decrease in wine consumption from 1964-1980 may have contributed to the decline in CVD mortality in Spain during 1975-1993.

Aged↗

PubMedDate not supplied

Some considerations of multi-variate hospital statistics.

At the University Hospital in Kiel data on the medical care and administration of individual patients is collected in a hospital information system. The description leads to lists of all cases treated, arranged according to basic data descriptions, and to tabulations of aggregated data. The aim of these statistics is to provide an overview of the collected data. At present the statistics can do little more than offer some general impressions about the frequency of serious diseases requiring hospitalization and health-care needs of a particular region; this is because they are selected and therefore biased and misleading. An accurate epidemiological view of a region to evaluate the quality, efficiency and cost of its health-care system can only be obtained if all the hospitals in that area are producing summarized information. So correlation of population statistics, broken down by patients' residential area and the hospital means for evaluating the health-care demands and consumption of a particular population, and for regional planning when figures for catchment area and attraction rate are produced.

Adolescent↗