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At least 109 records · Page 6Linked to original sources

PubMed2004

A pressure ulcer audit and feedback project across multi-hospital settings in the Netherlands.

OBJECTIVE: To examine whether participating in a pressure ulcer prevalence survey and receiving feedback results in an improvement in quality of care. DESIGN: Cross-sectional studies from 1998 to 2002 were compared over time. SETTING: Sixty-two acute care hospitals in the Netherlands. STUDY PARTICIPANTS: Patients hospitalized at the moment of the surveys. INTERVENTIONS: Each hospital was given hospital-specific performance data and national aggregate data, and peer comparisons to improve the quality of care. MAIN OUTCOME MEASURES: The case-mix-adjusted prevalence of pressure ulcers of grade >or=2, the percentage of high-risk patients receiving adequate prevention, and the total number of enabling conditions present were compared between successive surveys using multi-level analysis, in order to estimate a linear trend model and trend differences for each hospital. RESULTS: The case-mix-adjusted prevalence of pressure ulcers decreased over the 5-year period, while the percentage of patients receiving adequate prevention and the total number of enabling conditions present increased. The total number of enabling conditions had a significant effect on the decrease in case-mix-adjusted prevalence: more enabling conditions led to a lower case-mix-adjusted prevalence (chi(2) = 125; degrees of freedom = 1; P < 0.00). The percentage of patients receiving adequate prevention also had an effect on the change in case-mix-adjusted prevalence, with a higher percentage leading to a lower case-mix-adjusted prevalence. This effect, however, was not significant. CONCLUSIONS: Monitoring prevalence and giving feedback results in an improvement in quality of care in terms of pressure ulcer prevention. It is very important to continue conducting surveys to avoid attention moving away from this topic, which may in turn lead to a deterioration in the quality of pressure ulcer care. Further research to find the most effective feedback approach is needed.

Aged↗

PubMed2006

Routinely-collected general practice data are complex, but with systematic processing can be used for quality improvement and research.

BACKGROUND: UK general practice is computerised, and quality targets based on computer data provide a further incentive to improve data quality. A National Programme for Information Technology is standardising the technical infrastructure and removing some of the barriers to data aggregation. Routinely collected data is an underused resource, yet little has been written about the wide range of factors that need to be taken into account if we are to infer meaning from general practice data. OBJECTIVE: To report the complexity of general practice computer data and factors that need to be taken into account in its processing and interpretation. METHOD: We run clinically focused programmes that provide clinically relevant feedback to clinicians, and overview statistics to localities and researchers. However, to take account of the complexity of these data we have carefully devised a system of process stages and process controls to maintain referential integrity, and improve data quality and error reduction. These are integrated into our design and processing stages. Our systems document the query, reference code set and create unique patient ID. The design stage is followed by appraisal of: data entry issues, how concepts might be represented in clinical systems, coding ambiguities, using surrogates where needed, validation and pilot-ing. The subsequent processing of data includes extraction, migration and integration of data from different sources, cleaning, processing and analysis. RESULTS: Results are presented to illustrate issues with the population denominator, data entry problems, identification of people with unmet needs, and how routine data can be used for real-world testing of pharmaceuticals. CONCLUSIONS: Routinely collected primary care data could contribute more to the process of health improvement; however, those working with these data need to understand fully the complexity of the context within which data entry takes place.

Ambulatory Care Information Systems↗

PubMedDate not supplied

Clinical highlights from the National Cancer Data Base, 1999.

The National Cancer Data Base (NCDB), a joint project of the Commission on Cancer of the American College of Surgeons and the American Cancer Society, collects and analyzes data from a wide variety of sources throughout the United States, including small community hospitals. Due to this unique reporting system, individual facilities can compare their own data with the aggregate data from the NCDB, using their findings to evaluate local patient care practices. This article highlights the principal findings of the NCDB and Patient Care Evaluation articles published in 1998 on breast, prostate, cervical, endometrial, gallbladder, head and neck, nasopharyngeal, rectal, thyroid, and vaginal cancers, as well as on melanoma, brain tumors, and Hodgkin's disease. With more than five million cancer cases in the NCDB for the years between 1985 and 1995, sufficient numbers of even rare cancers have been accrued to permit some types of epidemiologic and clinical assessments.

Adolescent↗

PubMed1990

Approach-withdrawal and cerebral asymmetry: emotional expression and brain physiology. I.

In this experiment, we combined the measurement of observable facial behavior with simultaneous measures of brain electrical activity to assess patterns of hemispheric activation in different regions during the experience of happiness and disgust. Disgust was found to be associated with right-sided activation in the frontal and anterior temporal regions compared with the happy condition. Happiness was accompanied by left-sided activation in the anterior temporal region compared with disgust. No differences in asymmetry were found between emotions in the central and parietal regions. When data aggregated across positive films were compared to aggregate negative film data, no reliable differences in brain activity were found. These findings illustrate the utility of using facial behavior to verify the presence of emotion, are consistent with the notion of emotion-specific physiological patterning, and underscore the importance of anterior cerebral asymmetries for emotions associated with approach and withdrawal.

Adolescent↗

PubMed1987

Comparison of relative risks obtained in ecological and individual studies: some methodological considerations.

This paper is concerned with the problem of estimating relative risks from ecological correlation studies. In the first part, some of the biases encountered when analysing aggregated data are discussed and in particular attention is focused on the shape of the dose-response relationship obtained from aggregated and non-aggregated data, on the need for extrapolation and on the scale of aggregation. In the second part some empirical observations are made on these points by means of four examples concerning the relative risk between smoking and different pathologies. The estimates of relative risks derived from French geographical data and from case control or cohort studies are compared. The performance of ecological studies is discussed with respect to the strength of the risk factor considered, the geographical distribution of counfounding factors and the adjustment of different models.

Adult↗

PubMed1997

Modeling of time trends and interactions in vital rates using restricted regression splines.

For the analysis of time trends in incidence and mortality rates, the age-period-cohort (apc) model has became a widely accepted method. The considered data are arranged in a two-way table by age group and calendar period, which are mostly subdivided into 5- or 10-year intervals. The disadvantage of this approach is the loss of information by data aggregation and the problems of estimating interactions in the two-way layout without replications. In this article we show how splines can be useful when yearly data, i.e., 1-year age groups and 1-year periods, are given. The estimated spline curves are still smooth and represent yearly changes in the time trends. Further, it is straightforward to include interaction terms by the tensor product of the spline functions. If the data are given in a nonrectangular table, e.g., 5-year age groups and 1-year periods, the period and cohort variables can be parameterized by splines, while the age variable is parameterized as fixed effect levels, which leads to a semiparametric apc model. An important methodological issue in developing the nonparametric and semiparametric models is stability of the estimated spline curve at the boundaries. Here cubic regression splines will be used, which are constrained to be linear in the tails. Another point of importance is the nonidentifiability problem due to the linear dependency of the three time variables. This will be handled by decomposing the basis of each spline by orthogonal projection into constant, linear, and nonlinear terms, as suggested by Holford (1983, Biometrics 39, 311-324) for the traditional apc model. The advantage of using splines for yearly data compared to the traditional approach for aggregated data is the more accurate curve estimation for the nonlinear trend changes and the simple way of modeling interactions between the time variables. The method will be demonstrated with hypothetical data as well as with cancer mortality data.

Age Factors↗

PubMed2001

Polar value analysis of refractive data.

PURPOSE: To demonstrate the use of polar value analysis of surgically induced astigmatism (SIA). SETTING: Department of Ophthalmology, Arhus University Hospital, Arhus, Denmark. METHODS: Univariate polar value analysis of SIA was demonstrated for a single patient and for aggregate data. Bivariate polar value analysis was performed for aggregate data. RESULTS: The meridional polar value AKP expresses the surgically induced flattening, while the oblique polar value AKP(+45) indicates the torque. This pair of polar values characterizes a regular astigmatism completely. In bivariate polar value analysis, the average SIA is the combined mean for AKP and AKP(+45), while the spread is a confidence area delineated by an ellipse. CONCLUSIONS: Univariate and bivariate polar value analyses, together with the surgically induced change in spherical equivalent power, yield an exact description of surgically induced change following refractive procedures.

Adult↗

PubMed1986

A computerized multichannel platelet aggregometer system.

Commercially available instrumentation for conducting platelet aggregation studies in clinical and research laboratories consists of one-, two-, or four-channel aggregometers used in conjunction with strip chart recorders. These instruments have limited utility in large-scale drug screening and evaluation of the mode of action of drugs or in the clinical diagnosis of platelet disorders. A new instrument, a computerized multichannel aggregometer system (CMPAS) has been developed to collect, display, and analyze platelet aggregation data. The system is comprised of a 24-channel Born-type aggregometer, interfaced to a Rockwell AIM-65 microcomputer through an analogue-to-digital converter and an Epson dot-matrix printer. Each channel is individually calibrated, and aggregation data can be collected on up to 24 different platelet-rich plasma samples simultaneously. Conversational programs written in BASIC prompt the user for the addition of agonists and inhibitors. The tracings for each channel are displayed simultaneously, and a program automatically analyzes the data to generate the following parameters: baseline optical density, maximum aggregation response, positive and negative slopes, time to peak aggregation, and percentage response. Computerized multichannel aggregometer system data outputs are comparable to data generated by a standard Chronolog aggregometer unit. The advantages of the system include multichannel capability, simultaneous display of all channels allowing relative comparisons between control and experimental groups, and time savings and improved efficiency in conducting and analyzing aggregation experiments.

Animals↗

PubMedDate not supplied

The competency question.

JCAHO mandates "processes that are designed to ensure that the competency of all staff members is assessed, maintained, demonstrated, and improved on an ongoing basis." However, it is difficult to collect aggregate data regarding staff competency patterns and trends. How many facilities have the time or energy to collect aggregate data, let alone statistically analyze it for patterns and trends? Not many in today's environment. I saw the need to create a test to evaluate staff competency at my facility, but soon realized I would have no way of knowing if the results were good or bad. The only way to judge the results would be to have a standardized test that was used by multiple facilities. As president of the Houston X-ray Quality Society, I brought the topic up at a meeting in 1995, and a committee was set up to work on the test. The result is two competency tests--one for staff radiographers and one for mammographers--which are currently used by 35 to 40 facilities, with approximately 1,000 technologists taking the test each year. The tests include practical questions that reflect the knowledge required to perform daily exams. Each test has five sections that assess different areas of competency. The scoring system allows technologists to fail one or more individual sections but still pass the test overall. Twenty to 30 percent of the questions are new each year. That gives us the ability to look for improvement on previous year's questions, and at the same time, avoid producing a static and ineffective test. There are 60 questions on the staff radiographer test and 65 questions on the mammographer test, which also includes clinical images. Facilities must sign an agreement that states that they cannot use the test as a disciplinary tool in the employee's evaluation, or in any other way against the technologist. As a profession, radiology administration not only has regulatory requirements to evaluate competency, but also a moral duty to insure that patients receive the best possible care. We should not cover up or ignore the blemishes that we all know exist. Instead, we should take them on, as professional and personal challenges to improve the competency of our staff.

Benchmarking↗

PubMed2003

Geographic analysis of diabetes prevalence in an urban area.

The objective of this research is to identify the sociodemographic, environmental, and lifestyle factors associated with the geographic variability of Diabetes Mellitus (DM) prevalence in the City of Winnipeg, Manitoba in Canada. An ecological regression study design was employed for this purpose. The study population included all prevalent cases of DM in 1998 for Winnipeg. Predictor and outcome data were aggregated for analysis using two methods. First, the spatial scan statistic was used to aggregate study data into highly probable diabetes prevalence clusters. Secondly, predictor and outcome data were aggregated to existing administrative health areas. Analysis of variance and spatial and non-spatial linear regression techniques were used to explore the relationship between predictor and outcome variables. The results of the two methods of data aggregation on regression results were compared. Mapping and statistical analysis revealed substantial clustering and small-area variations in the prevalence of DM in the City of Winnipeg. The observed variations were associated with variations in socioeconomic, environmental and lifestyle characteristics of the population. The two methods of data aggregation used in the study generated very similar results in terms of identifying the geographic location of DM clusters and of the population characteristics ecologically correlated to those clusters. High rates of DM prevalence are strongly correlated with indicators of low socioeconomic status, poor environmental quality and poor lifestyles. This analysis further illustrates what a useful tool the spatial scan statistic can be when used in conjunction with ecological regression to explore the etiology of chronic disease.

Analysis of Variance↗

PubMed1989

Validity of international, time trend, and migrant studies of dietary factors and disease risk.

A linear form relative risk model is used to identify circumstances in which various types of aggregate data lead to valid inferences on relative risk parameters. Upon making a random effects assumption, international or time trend data can lead to appropriate relative risk parameter estimation using iteratively reweighted least-squares procedures. Adequate confounding factor control, however, will typically require data on the distribution of confounding factors in each country or time period. For a simple interpretation of relative risk parameters one may also require data on the joint distribution of primary and confounding factors in each country or time period. Hence disease rate data need to be supplemented by dietary and risk factor survey data in order to avoid confounding bias. Measurement error in individual dietary assessment may, however, limit the ability to quantify the dependence of relative risk on dietary factors, unless the relative risk function is approximately linear in the dietary factors of interest. Most studies of migrant populations involve a comparison of migrant mortality rates with those of their countries of emigration and immigration, with little or no data collection on the dietary habits and risk factors of the migrants themselves. The potential of more comprehensive aggregate data and analytic migrant studies in the diet and disease area is briefly indicated. These issues and methods are illustrated using various types of data pertinent to the association between dietary fat and breast cancer.

Breast Neoplasms↗

PubMed1995

Framework for the development of environmental health indicators.

Environmental health indicators provide information about scientifically-based linkages between environment and health. This information can be used for environmental health management and decision-making. Environmental health indicators are rendered more complex than either environmental indicators or health indicators because they must take account of factors such as the variability in susceptibility in individuals and variability in co-exposures. Such variability implies that any links that are defined may not apply to all individuals or groups at all times. Individual-level epidemiological studies can contribute to establishing environmental health relationships for particular places and time periods. However, cost-efficiency demands that aggregated data and known environment and health relationships be used to derive these indicators. Environmental health indicators can therefore be constructed by linking aggregated data, or by identifying environmental indicators with a health linkage, or health indicators with an environmental linkage. The framework for environmental health indicators proposed here is an adaptation of the Pressure-State-Response framework. Its first level consists of driving forces, which create pressures on the environment. These in turn alter the state of the environment by increasing existing exposures or introducing new ones, which produces a measurable health effect. In order to rectify the problem, actions (i.e., environmental health management) must be undertaken at each level. Thus the framework becomes the Driving-force--Pressure--State--Effects--Action (DPSEA).

Causality↗

PubMed1992

Drug product management in health maintenance organizations.

A national mail survey of drug product management in health maintenance organizations (HMOs) is described. The survey covered 570 HMOs--502 by questionnaires mailed to pharmacy directors at individual independent and multistate HMOs and 68 represented by six executives of multistate HMOs who agreed to report aggregate data for their HMO operations. Responses for 180 individual HMOs were received (36% response rate); four of the six multistate HMO executives returned aggregate data. Individual HMO respondents reported using the following methods of drug product management: formularies, 66% (of these, 60% reported using a restrictive formulary or a restrictive formulary with exceptions); MACs, 54%; prior authorization, 44%; contracts for co-marketed and single-source drug entities, 46% for each. Almost all HMOs with contracts also had exclusive or preferred status for dispensing or reimbursement of some drug products. Most HMOs received discounts, manufacturer's value-added services, price protection, rebates based on market share, and rebates based on use as contract incentives; discounts and rebates based on use were chosen as the most preferred incentives. Established methods of drug product management, such as formularies and MACs, were most commonly reported by HMOs; however, nearly half reported using new approaches, including contracts with manufacturers, incentives, such as discounts and rebates based on use, and exclusive or preferred status.

Contract Services↗

PubMed1999

Parallel analyses of individual and ecologic data on residential radon, cofactors, and lung cancer in Sweden.

Divergent results from ecologic and analytic studies on residential radon and lung cancer have created uncertainty in terms of risk assessment. The authors performed concurrent analyses on individual and aggregated data from the nationwide case-control study of residential radon and lung cancer in Sweden. For data aggregated on the county level, the ecologic excess relative risk estimates per 100 Bqm(-3) residential radon concentration ranged from -0.03 (95% confidence interval (CI) -0.21 to 0.15) to 0.00 (95% CI -0.21 to 0.21) with different adjustment for cofactors. For individual-level data, the average within-county excess relative risk estimates ranged from 0.07 (95% CI -0.01 to 0.15) to 0.11 (95% CI 0.01-0.27) with similar adjustment. Effect modification by differential county-level radon-smoking correlations appeared insufficient as an explanation for ecologic bias in the Swedish data. On the other hand, adjustment for latitude led to congruence between the two levels of analysis. The results confirm that ecologic studies may be misleading in studies of weak associations, even when major risk factors are accounted for. The large impact of latitude may be unique to Sweden and due to the correlation of latitude both with residential radon and other determinants of lung cancer risk.

Adult↗

PubMed1995

[Time series analysis in environmental epidemiology: short-term effects of air pollution on mortality and morbidity].

This work gives an overview of design and analysis of temporal studies using aggregated data in air pollution epidemiology. In the last years time series are often used to study the short-term association between ambient air pollution levels and aggregated health data. Health endpoints are usually daily mortality and/or daily hospital admission data from routine health registers. Air quality data are commonly obtained from one (or a few) fixed site monitoring stations. To detect the temporal association between the time-pattern in air pollution and the time-pattern in health data particular attention needs to be given to the autocorrelation structure, to the seasonality and long term trend in the data, and to the weather variables. Poisson regression with autocorrelated residuals is the suitable statistical method to analyze time studies. Furthermore, the pollutant variable can be analyzed at different lag-times to account for short latency periods in the manifestation of diseases. Studies with temporal aggregated data show the same disadvantages of the ecologic studies, although, in this case, confounding is less of a problem. Temporal studies usually are based on a large database, so that sufficient power can be achieved to detect even weak associations. Finally, the exposure information on subjects is often better characterized by short-term fluctuations in ambient air quality than is the case in geographic aggregations.

Air Pollutants↗

PubMed2005

Seizure anticipation, states of consciousness and marginal predictability in temporal lobe epilepsy.

PURPOSE: It has recently been shown that differences between the marginal predictability associated with scalp electrodes adjacent to and remote from the site of a seizure focus are able to distinguish between epochs temporally distant from and just prior to (within about 20 min) the onset of a seizure in patients with temporal lobe epilepsy. The purpose of this paper is to show that these differences of marginal predictability intervals are independent of the state of consciousness of the patient. METHODS: We have studied a data set encompassing 33 preictal epochs (within 1 h prior to a seizure) and 61 interictal epochs (defined as at least 1 h away from any seizure) from 14 patients. Each 30 s interval of each epoch was categorized into one of seven different states of consciousness. Statistical models were used to search for relationships (in aggregated data) between the values of differences of marginal predictabilities and state of consciousness. RESULTS: It was not possible to reject the null hypothesis of no relationship between differences of marginal predictabilities and state of consciousness. CONCLUSIONS: The values of the differences between marginal predictabilities on aggregated data are apparently insensitive to the state of consciousness. This conclusion, coupled with the fact that the differences between marginal predictabilities do depend on time to seizure, suggests the potential utility of these measures as the basis for ambulatory, non-invasive methods of seizure anticipation. However, the development of a practical non-invasive method for seizure anticipation requires further extensive study on disaggregated data from individual patients.

Adolescent↗

PubMedDate not supplied

National Emergency Medical Services Information System (NEMSIS).

The absence of emergency medical services (EMS) patient care data has hindered development and evaluation of EMS systems. The National Highway Traffic Safety Administration (NHTSA), in cooperation with the Health Resources and Services Administration (HRSA), has provided funding to the National Association of State EMS Directors to develop a National EMS Information System (NEMSIS). NEMSIS is being designed to provide a uniform national EMS dataset, with standard terms, definitions, and values, as well as a national EMS database, with aggregated data from all states on a limited number of data elements. Forty-eight of the states, the District of Columbia, and three territories signed a memorandum of agreement documenting support for the NEMSIS project and expressing a desire for full implementation of the NEMSIS dataset. NHTSA has agreed to house the National EMS Database at its National Center for Statistics and Analysis. NHTSA, in cooperation with HRSA and the Centers for Disease Control and Prevention, recently entered into a cooperative agreement with the University of Utah School of Medicine to operate a NEMSIS Technical Assistance Center that will provide related assistance to official EMS agencies and to commercial software vendors. The Technical Assistance Center will also biannually assess state and territorial capabilities to provide data to the national EMS database. NEMSIS will provide a uniform national EMS dataset, with standard terms, definitions, and values, as well as a national EMS database, with aggregated data from all states on a limited number of data elements. Many of the potential benefits of implementation of NEMSIS are enumerated in this report.

Databases as Topic↗

PubMed1998

What is Germany's experience on reference based drug pricing and the etiology of adverse health outcomes or substitution?

Germany is frequently cited as an example of reference based pricing (RBP) in ongoing controversial discussions on the effect of RBP. There are thorough analyses of phase I and II RBP on Germany's drug market. However, any conclusions on the overall economic and public health impact of RBP, solely on the basis of aggregated data, must be suspect to substantial bias, since too many factors in a rapidly changing health care system remained uncontrolled. Parallel to the introduction of phase II RBP in 1992/1993, the second health care reform became active. The two major confounding factors were the introduction of fixed drug budgets and the many changes due to the unification of Germany that took place in the beginning of the 1990s. Published and unpublished aggregated data do not allow any conclusions on the etiology of adverse health events due to this change in drug reimbursement policy. Conclusions drawn from the German experience will be based on assumptions or speculations that are hard to prove. A health care system that identifies enough evidence and need to introduce RBP as a measure of cost control should make every effort to evaluate the effects in order to increase program compliance or, if indicated, make adaptations to the RBP policy. The introduction of RBP in British Columbia in 1995-1997 and its computerized administrative health databases covering a large proportion of the population should give rise to a thorough analysis of this policy.

Canada↗