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 829 records · Page 46Linked to original sources

PubMed2003

Information system concepts for quality measurement.

BACKGROUND: Health care information systems in use today frequently fall short of what is needed to meet the demands for data and reporting on performance. Many observers believe substantial improvements in information systems will be necessary if the potential of a national quality measurement and reporting system (NQMRS) is to be realized. A shared vision will facilitate progress in improving information systems. OBJECTIVES: To articulate a set of guiding principles and operational steps for the development of functional information systems in health care. RESEARCH DESIGN: Experience in building such systems for one health care delivery system was used to develop an approach. This was discussed with Strategic Framework Board members and integrated with other considerations for going from a local system to one that could accumulate information for national purposes. FINDINGS: The key elements of a functional information system include provisions that (1) data should be collected once, (2) aggregation of data for higher-level reports should be anticipated, (3) issues related to privacy and confidentiality must be addressed, and (4) measurement systems should include an audit standard. A seven-step process for developing a functional information system is outlined. CONCLUSIONS: A shared national measurement framework is essential because the data systems that health care delivery organizations use are not static. A long-term vision can guide the growth of a data system over time. An NQMRS can be the vehicle that provides the needed vision.

Confidentiality↗

PubMedDate not supplied

Identifying participation rates at outpatient cardiac rehabilitation programs in Victoria, Australia.

BACKGROUND: Much has been achieved in implementing structured outpatient cardiac rehabilitation (CR) programs in Victoria, Australia, but little is known about the percentage of eligible patients who participate. This study was undertaken to determine the feasibility of establishing a database of CR participants and comparing it to the Victorian Inpatient Minimum Database (VIMD), a routinely collected hospital morbidity data set documenting all admissions to Victorian public and private hospitals. This would enable program participants and nonparticipants to be identified and program participation rates to be calculated. METHODS: Data on program participants were collected from a sample of eight CR programs. Records from the VIMD were extracted for the concurrent time period for patients discharged home after acute myocardial infarction (AMI), coronary artery bypass graft (CABG) surgery, and percutaneous transluminal coronary angioplasty (PTCA), and therefore considered eligible to participate. Victorian Inpatient Minimum Database data were aggregated according to program catchment areas. Data were compared for program participants and patients eligible to participate. RESULTS: Seven hundred fifty-eight patients were identified as being eligible to attend; 240 (32%) were identified as participating at least once. Discharged CABG patients participated on average at a rate of 53.1%, compared with 27.2% of AMI patients and only 10.3% of PTCA patients. CONCLUSIONS: Despite a comprehensive network of CR programs in Victoria, they are used on average by only a minority of eligible patients. Further work is required to determine barriers to participation to develop strategies to increase participation rates.

Aged↗

PubMed1999

A taxonomy of health networks and systems: bringing order out of chaos.

OBJECTIVE: To use existing theory and data for empirical development of a taxonomy that identifies clusters of organizations sharing common strategic/structural features. DATA SOURCES: Data from the 1994 and 1995 American Hospital Association Annual Surveys, which provide extensive data on hospital involvement in hospital-led health networks and systems. STUDY DESIGN: Theories of organization behavior and industrial organization economics were used to identify three strategic/structural dimensions: differentiation, which refers to the number of different products/services along a healthcare continuum; integration, which refers to mechanisms used to achieve unity of effort across organizational components; and centralization, which relates to the extent to which activities take place at centralized versus dispersed locations. These dimensions were applied to three components of the health service/product continuum: hospital services, physician arrangements, and provider-based insurance activities. DATA EXTRACTION METHODS: We identified 295 health systems and 274 health networks across the United States in 1994, and 297 health systems and 306 health networks in 1995 using AHA data. Empirical measures aggregated individual hospital data to the health network and system level. PRINCIPAL FINDINGS: We identified a reliable, internally valid, and stable four-cluster solution for health networks and a five-cluster solution for health systems. We found that differentiation and centralization were particularly important in distinguishing unique clusters of organizations. High differentiation typically occurred with low centralization, which suggests that a broader scope of activity is more difficult to centrally coordinate. Integration was also important, but we found that health networks and systems typically engaged in both ownership-based and contractual-based integration or they were not integrated at all. CONCLUSIONS: Overall, we were able to classify approximately 70 percent of hospital-led health networks and 90 percent of hospital-led health systems into well-defined organizational clusters. Given the widespread perception that organizational change in healthcare has been chaotic, our research suggests that important and meaningful similarities exist across many evolving organizations. The resulting taxonomy provides a new lexicon for researchers, policymakers, and healthcare executives for characterizing key strategic and structural features of evolving organizations. The taxonomy also provides a framework for future inquiry about the relationships between organizational strategy, structure, and performance, and for assessing policy issues, such as Medicare Provider Sponsored Organizations, antitrust, and insurance regulation.

American Hospital Association↗

PubMed1995

Estimating annual charges for ambulatory care from limited utilization data.

OBJECTIVE: This study explores the types of utilization information needed to produce a reasonable estimate of annual charges for ambulatory care that could be used in the absence of charge or cost data as an aggregate utilization measure. DATA SOURCE: Charge and utilization data from the RAND Health Insurance Experiment were used. STUDY DESIGN: Services provided to enrollees in the Health Insurance Experiment at each of the six sites for a one-year period were grouped into categories according to California Relative Value Studies (CRVS) codes. Using annual charges as the dependent variable, we evaluated linear regression models for their predictive accuracy, as indicated by adjusted R2-values. Categories of services were combined on the basis of clinical meaningfulness (e.g., all provider visits into one group), and predictive accuracy of models with these groupings of services examined. We examined model validity by applying the derived models to each of the 30 remaining site-years of data from the Health Insurance Experiment. PRINCIPAL FINDINGS: We were able to explain 84 percent of the variance in charges with a model containing counts of provider visits exclusive of mental health visits, mental health provider visits, days drugs were prescribed, days radiologic procedures were performed, procedural visits subdivided according to whether they were performed by a surgical or medical provider, days laboratory and/or pathology tests were performed, days a grouping of miscellaneous tests were performed, and days supplies were purchased. When applied to the validation data, this model predicted a mean of 77 percent of the variance and mean charges 102 +/- 9 percent of actual mean charges. A model with only the first four of the listed categories explained 77 percent of the variance in charges. CONCLUSIONS: Models using only counts of several broad categories of services perform rather well in predicting annual charges for ambulatory care.

Ambulatory Care↗

PubMed2003

Reconsidering the use of rankings in the valuation of health states: a model for estimating cardinal values from ordinal data.

BACKGROUND: In survey studies on health-state valuations, ordinal ranking exercises often are used as precursors to other elicitation methods such as the time trade-off (TTO) or standard gamble, but the ranking data have not been used in deriving cardinal valuations. This study reconsiders the role of ordinal ranks in valuing health and introduces a new approach to estimate interval-scaled valuations based on aggregate ranking data. METHODS: Analyses were undertaken on data from a previously published general population survey study in the United Kingdom that included rankings and TTO values for hypothetical states described using the EQ-5D classification system. The EQ-5D includes five domains (mobility, self-care, usual activities, pain/discomfort and anxiety/depression) with three possible levels on each. Rank data were analysed using a random utility model, operationalized through conditional logit regression. In the statistical model, probabilities of observed rankings were related to the latent utilities of different health states, modeled as a linear function of EQ-5D domain scores, as in previously reported EQ-5D valuation functions. Predicted valuations based on the conditional logit model were compared to observed TTO values for the 42 states in the study and to predictions based on a model estimated directly from the TTO values. Models were evaluated using the intraclass correlation coefficient (ICC) between predictions and mean observations, and the root mean squared error of predictions at the individual level. RESULTS: Agreement between predicted valuations from the rank model and observed TTO values was very high, with an ICC of 0.97, only marginally lower than for predictions based on the model estimated directly from TTO values (ICC = 0.99). Individual-level errors were also comparable in the two models, with root mean squared errors of 0.503 and 0.496 for the rank-based and TTO-based predictions, respectively. CONCLUSIONS: Modeling health-state valuations based on ordinal ranks can provide results that are similar to those obtained from more widely analyzed valuation techniques such as the TTO. The information content in aggregate ranking data is not currently exploited to full advantage. The possibility of estimating cardinal valuations from ordinal ranks could also simplify future data collection dramatically and facilitate wider empirical study of health-state valuations in diverse settings and population groups.

Journal Article↗

PubMed1999

Use of the Decision Support System for VA cost-effectiveness research.

BACKGROUND: The Department of Veterans Affairs is adopting the Decision Support System (DSS), computer software and databases which include a cost-accounting system which determines the cost of health care products and patient encounters. OBJECTIVES: A system for providing cost data for cost-effectiveness analysis should be provide valid, detailed, and comprehensive data that can be aggregated. METHODS: The design of DSS is described and compared with those criteria. Utilization data from DSS was compared with other VA utilization data. Aggregate DSS cost data from 35 medical centers was compared with relative resource weights developed for the Medicare program. RESULTS: Data on hospital stays at 3 facilities found that 3.7% of the stays in DSS were not in the VA discharge database, whereas 7.6% of the stays in the discharge data were not in DSS. DSS reported between 68.8% and 97.1% of the outpatient encounters reported by six facilities in the ambulatory care data base. Relative weights for each Diagnosis Related Group based on DSS data from 35 VA facilities correlated with Medicare weights (correlation coefficient of .853). CONCLUSIONS: DSS will be useful for research if certain problems are overcome. It is difficult to distinguish long-term from acute hospital care. VA does not have a complete database of all inpatient procedures, so DSS has not assigned them a specific cost. The authority to access encounter-level DSS data needs to be centralized. Researchers can provide the feedback needed to improve DSS cost estimates. A comprehensive encounter-level extract would facilitate use of DSS for research.

Cost-Benefit Analysis↗

PubMed1990

The impact of the 23-hour patient on nursing workload.

Decreasing length of in-patient stay and increasing the number of outpatient procedures being performed has led to the creation of the 23/24-hour observation patient. In this study, the authors show that the addition of observation patients to aggregate workload data causes a meaningful staffing deficit 60-90% of the time in three out of four clinical areas studied. The authors explore the statistical impact on staffing of the addition of observation patients to aggregate inpatient data and provide several strategies for staffing.

Ambulatory Care↗

PubMed1997

A comparison of breast, colorectal, lung, and prostate cancers reported to the National Cancer Data Base and the Surveillance, Epidemiology, and End Results Program.

BACKGROUND: The National Cancer Data Base (NCDB) is an information resource and program evaluation tool of the American College of Surgeons Commission on Cancer and the American Cancer Society that uses a hospital-based cancer reporting system. The Surveillance, Epidemiology, and End Results (SEER) program is a population-based registry program of the National Cancer Institute. The purpose of this investigation was to compare the aggregate NCDB data for selected cancer types from a given year with comparable SEER data. METHODS: SEER data from 1992 on 18,322 breast, 13,427 colorectal, 15,276 lung, and 21,501 prostate cancers were compared with NCDB data on 96,323 breast, 69,456 colorectal, 108,702 lung, and 107,690 prostate cancers. RESULTS: Similar levels of data completeness were observed. The NCDB data tended to contain less complete information about the Spanish or Hispanic ethnicity of patients. Tumor grade data tended to be incomplete in both series. Stage information about lung and prostate cancer was more often missing in SEER data. Patient age, race, and gender in NCDB data differed little from corresponding SEER data, except that SEER data reported a greater proportion of patients in the "other" race category that included Asian-Americans and American Indians. Tumor laterality, anatomic site, tumor grade, and types of surgical treatment were similar in the NCDB and SEER data. Radical mastectomy was performed in 49.4% of SEER breast cancer cases compared with 49.2% of NCDB cases. Cancer-directed surgery was observed less often among SEER prostate cancer cases than among NCDB cases. The NCDB data also indicated greater use of radiation therapy than the SEER data for the four types of cancer reviewed. CONCLUSIONS: The 1992 NCDB data, in aggregate, described patient and disease treatment characteristics and patterns that differed only marginally from those described in the SEER data from the same year.

Adult↗

PubMed2004

Schools for the deaf and the No Child Left Behind Act.

The No Child Left Behind Act of 2001 (NCLB) emphasizes educational accountability for all students. Twenty-eight states have policies to aggregate student participation and proficiency data for schools for the deaf in NCLB reports. The remaining states account for these students in other ways: referring student data to "sending" schools and aggregating data to the district or state level are most prominent. In reports of student assessment results for academic year 2002-2003, three schools for the deaf made "Adequate Yearly Progress" under NCLB: These schools demonstrated at least a 95% participation rate in assessments, and at least 95% of their students met or surpassed state proficiency benchmarks in reading and mathematics. Proficiency levels for other schools varied by report, but were often comparable to those of students with disabilities. Challenges and strategies for capturing the impact of NCLB accountability policies on deaf students are discussed.

Benchmarking↗

PubMed2000

A search for aggregate-level effects of education on fertility, using data from Zimbabwe.

The analysis was based on the 1994 Zimbabwe Demographic and Health Survey combined with aggregate data from the 1992 census. Discrete-time hazard models for first and higher-order births were estimated for 1990-94. The average length of education in the district and the proportion who are literate were found to have no impact on a woman's birth rate above and beyond that of her own education, when it was controlled for urbanization. This was the case for women who themselves had little or no education as well as for the better educated. So far, no significant influence of aggregate education on fertility has been well documented in the literature either. However, in this study, aggregate-level effects appeared in models for fertility desires and contraceptive use among married women with at least one child.

Africa↗

PubMed1998

Patients with venous stasis ulceration have increased monocyte-platelet aggregation.

PURPOSE: Leukocyte activation has been implicated in the pathogenesis of venous stasis ulceration, but the involvement of activated platelets and leukocyte-platelet aggregates has not been previously investigated. The purpose of this study was to determine whether patients with venous stasis ulceration have increased platelet activation and a propensity toward formation of leukocyte-platelet aggregates. METHODS: Blood was drawn from the superficial veins of the leg just proximal to a venous stasis ulcer and from an antecubital vein in 14 patients with venous stasis ulceration. Blood was also drawn from the antecubital vein of 14 volunteers without evidence of venous disease. Whole-blood flow cytometry was used to analyze the samples before and after activation with a panel of agonists for evidence of platelet activation and the formation of leukocyte-platelet aggregates. RESULTS: Patients with venous stasis ulceration had a greater number of monocyte-platelet aggregates in both the arm and leg samples than did the control subjects (p < 0.01). Furthermore, antecubital blood samples from patients with venous stasis ulceration stimulated with either thrombin-receptor agonist peptide, adenosine diphosphate, or phorbol myristate acetate formed more monocyte-platelet aggregates than did control samples (p < 0.05). No differences in platelet activation or neutrophil-platelet aggregate formation were noted among the three sample groups. CONCLUSIONS: Patients with venous stasis ulceration have an increase in the number of monocyte-platelet aggregates in systemic venous blood as well as in venous blood adjacent to a venous stasis ulcer, implicating the monocyte as the leukocyte involved in the pathogenesis of venous stasis ulceration. No association was identified between the presence of a venous stasis ulcer and either neutrophil-platelet aggregation or the activation of individual platelets. Because platelet activation is necessary for the formation of monocyte-platelet aggregates, these data also suggest that monocyte-platelet aggregation is a more sensitive marker for in vivo platelet activation than is the identification of individual activated platelets.

Adenosine Diphosphate↗

PubMed2002

Kinetics of protein aggregation. Quantitative estimation of the chaperone-like activity in test-systems based on suppression of protein aggregation.

The experimental data on the kinetics of irreversible aggregation of proteins caused by exposure to elevated temperatures or the action of denaturing agents (guanidine hydrochloride, urea) have been analyzed. It was shown that the terminal phase of aggregation followed, as a rule, first order kinetics. For the kinetic curves registered by an increase in the apparent absorbance (A) in time (t) the methods of estimation of the corresponding kinetic parameters A(lim) and kI (A(lim) is the limiting value of A at t --> infinity and kI is the rate constant of the first order) have been proposed. Cases are revealed when the reaction rate constant kI calculated from the kinetic curve of aggregation of the enzymes coincides with the rate constant for enzyme inactivation. Such a situation is interpreted as a case when the rate of aggregation is limited by the stage of denaturation of the enzyme. A conclusion has been made that, in order to establish the mechanism of protein aggregation, the kinetic investigations of aggregation should be carried out over a wide range of protein concentrations. The refolding experiments after denaturation of proteins by guanidine hydrochloride or urea have been also analyzed. It was shown that aggregation accompanying refolding follows first order kinetics at the final phase of the process. The model of protein refolding explaining such a kinetic regularity has been proposed. When aggregation of protein substrate follows first order kinetics, parameters A(lim) and kI may be used for the quantitative characterization of the chaperone-like activity in the test-systems based on suppression of protein aggregation.

Animals↗

PubMed2005

Volatility: a new vital sign identified using a novel bedside monitoring strategy.

BACKGROUND: SIMON (Signal Interpretation and Monitoring) monitors and archives continuous physiologic data in the ICU (HR, BP, CPP, ICP, CI, EDVI, SVO2, SPO2, SVRI, PAP, and CVP). We hypothesized: heart rate (HR) volatility predicts outcome better than measures of central tendency (mean and median). METHODS: More than 600 million physiologic data points were archived from 923 patients over 2 years in a level one trauma center. Data were collected every 1 to 4 seconds, stored in a MS-SQL 7.0 relational database, linked to TRACS, and de-identified. Age, gender, race, Injury Severity Score (ISS), and HR statistics were analyzed with respect to outcome (death and ventilator days) using logistic and Poisson regression. RESULTS: We analyzed 85 million HR data points, which represent more than 71,000 hours of continuous data capture. Mean HR varied by age, gender and ISS, but did not correlate with death or ventilator days. Measures of volatility (SD, % HR >120) correlated with death and prolonged ventilation. CONCLUSIONS: 1) Volatility predicts death better than measures of central tendency. 2) Volatility is a new vital sign that we will apply to other physiologic parameters, and that can only be fully explored using techniques of dense data capture like SIMON. 3) Densely sampled aggregated physiologic data may identify sub-groups of patients requiring new treatment strategies.

Adult↗

PubMed1999

Speech and language therapy caseloads in seven districts in the UK.

This paper provides managers and clinicians with an analysis of routine data collected by seven speech and language therapy services in the UK. Managers in seven districts in the UK of varying size and location were asked to provide information on referrals, waiting times and attendances during the six month period, and to give a breakdown of the types of intervention offered and type of clients seen. These data were aggregated and comparisons were made with existing data on speech and language therapy services. The results revealed considerable variations in prevalence, staffing ratios and client management practices. The implications for service planning are discussed.

Adult↗

PubMed2006

Analysis of co-aggregation of cancer based on registry data.

OBJECTIVE: An exploratory analysis of co-aggregation of cancers using registry-based data. METHODS: We utilized sibships from over 18,000 families who had been recruited to the NCI-sponsored multi-institutional Cancer Genetics Network. The analysis assesses co-aggregation at the individual and family level and adjusts for ascertainment. RESULTS: We found statistically significant familial co-aggregation of lung cancer with pancreatic (adjusted p < 0.001), prostate (adjusted p < 0.003), and colorectal cancers (adjusted p = 0.004). In addition, we found significant familial co-aggregation of pancreatic and colorectal cancers (adjusted p = 0.018), and co-aggregation of hematopoietic and (non-ovarian) gynecologic cancers (adjusted p = 0.01). CONCLUSION: This analysis identified familial aggregation of cancers for which a genetic component has yet to be established.

Female↗

PubMed1999

Method for retrospective collection of work-related psychosocial risk factors for musculoskeletal disorders: reliability and aggregation.

Information on psychosocial work conditions during a 24-year period for 484 participants was collected retrospectively. Analyses were made of the interrater reliability, stability, specificity, and aggregation of data. The main finding was that it is possible to collect reliable information about psychosocial work conditions retrospectively for a long period of years when using a time ruler in a structured interview when earlier conditions are compared with the present. Interrater agreement was satisfactory for the larger part of the studied retrospective psychosocial risk factors and excellent for some of them. For most of the studied risk factors, the risk of overreporting exposure was low. The aggregation of data resulted in 2 indexes: poor social relations at work and low influence over work conditions. In conclusion, an individual time ruler works satisfactorily as a method of collecting retrospective information about psychosocial risk factors.

Adult↗

PubMed2006

Improving ecological inference using individual-level data.

In typical small-area studies of health and environment we wish to make inference on the relationship between individual-level quantities using aggregate, or ecological, data. Such ecological inference is often subject to bias and imprecision, due to the lack of individual-level information in the data. Conversely, individual-level survey data often have insufficient power to study small-area variations in health. Such problems can be reduced by supplementing the aggregate-level data with small samples of data from individuals within the areas, which directly link exposures and outcomes. We outline a hierarchical model framework for estimating individual-level associations using a combination of aggregate and individual data. We perform a comprehensive simulation study, under a variety of realistic conditions, to determine when aggregate data are sufficient for accurate inference, and when we also require individual-level information. Finally, we illustrate the methods in a case study investigating the relationship between limiting long-term illness, ethnicity and income in London.

Data Interpretation, Statistical↗

PubMed1991

[The role of adhesive proteins and membrane interactions in the processes of thrombocyte aggregation].

The reported data concerning the role of fibrinogen in platelet aggregation are reviewed and compared to the authors' experimental data obtained by electron microscopy and cytochemical techniques. Using fibrinogen and fibrinogen antibodies bound to colloidal gold, it has been shown that the presence of fibrinogen bridged between the adjoining cells is not necessary for primary platelet microaggregation stimulated by ADP or thrombin. The formation of direct interplatelet contacts resembling "pentalaminar membranes" has been shown to participate in that process. Some mechanisms are proposed to explain the enhanced adhesiveness of the activated platelet surfaces. Redistribution of phospholipids in the membrane bilayer leading to the exposure of negatively charged phospholipids may underlie that phenomenon. The clustering and internalization of "occupied" membrane receptors may also contribute to the formation of close contacts between platelets stimulated by primary agonists in the presence of exogenous fibrinogen and other adhesive proteins.

Adenosine Diphosphate↗