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Results for “Data Aggregation”

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PubMed1995

Can early re-admission rates accurately detect poor-quality hospitals?

There is widespread interest in using external quality measures, such as early re-admission rates (ERRs), to evaluate hospital quality. To evaluate the feasibility of using ERRs to identify poor-quality hospitals, a Monte Carlo simulation model was developed that describes the predictive power of ERRs for the 190 hospitals in Michigan using different assumptions concerning the distribution and variability of quality problems, the number of years of data aggregated, and unmeasured case-mix differences. The ability of ERRs to distinguish 171 average-quality hospitals from 19 poor-quality hospitals (assigned to have 5% vs. 15% premature discharges) was evaluated. First, the largest diagnosis-related groups (DRGs) were studied to determine if they included cardiac, gastrointestinal, pulmonary, and neurologic diseases. Despite using the highly optimistic assumptions that premature discharges are readmitted 50% more frequently than appropriately timed discharges and that no ERR variation was caused by unmeasured case-mix differences between hospitals, the results were poor. For example, for DRG 127 (heart failure), high ERR outlier status (using a .05 probability cutoff) had a positive predictive value of only 36%, meaning that approximately two thirds of hospitals labeled "poor-quality" (high ERR outliers) were false-positive results. Next, we repeated the simulation with sample sizes aggregated for all medical DRGs. The positive predictive value was 72%, but was very sensitive to ERR variability due to non-quality-related factors (e.g., unmeasured case mix). The positive predictive value decreases to 45% if unmeasured case mix accounts for even 10% of observed hospital ERR variation. The circumstances under which DRG-specific ERRs would be useful to detect poor-quality hospitals are unlikely to occur. Even collapsing to all medical DRGs, ERRs are likely to be accurate predictors only if quality differences are quite large and if unmeasured case-mix differences account for a small amount of interhospital variation in ERRs.

Computer Simulation↗

PubMed2003

Stratification of outcome for surgically treated unruptured intracranial aneurysms.

OBJECT: The combination of low anticipated rupture rates for many unruptured aneurysms, better delineation of treatment risks, and the availability of alternative modalities of treatment have led to heightened scrutiny of the surgical management of unruptured intracranial aneurysms. Most reports to date have provided aggregate data concerning surgical treatment risks. This study was performed to better delineate risk estimates for the surgical treatment of patients with unruptured intracranial aneurysms according to a patient's risk profile with regard to age, aneurysm location, and aneurysm size. METHODS: We studied 493 patients who were treated with surgical clipping of 604 unruptured saccular aneurysms. Information regarding aneurysm size, location, patient age, and 6-month or greater outcome were gathered prospectively from 1992 to 1999. Multivariate analysis was performed to identify independent risk factors for outcome. On the basis of the model, risk stratification curves were generated. RESULTS: In our series, the mean patient age was 53 years, and the mean lesion size was 8.8 mm. Lesion locations included the internal carotid artery (n = 259, 43%), the middle cerebral artery (n = 174, 28%), the anterior cerebral artery (n = 99, 17%), and the vertebrobasilar artery (n = 67, 11%). Multivariate analysis revealed that aneurysm size (beta = 0.122, P < 0.001), patient age (beta = 0.0308, P < 0.05), and vertebrobasilar location (beta = 1.37, P = 0.0080) were independently associated with high risk of poor outcome or death. CONCLUSION: Small aneurysms in the anterior circulation in young patients carry a very low treatment risk (approximately 1%), and treatment in elderly individuals (ages 70 years and older) with large lesions (greater than 10 mm), carries a significant risk of poor outcome (5% in the anterior circulation, 15% in the posterior circulation). The nomograms generated by this study should be particularly useful in discussing with patients the risks and benefits of surgical treatment of unruptured aneurysms.

Adult↗

PubMed2005

Comparison of early performance indicators for screening projects within the European Breast Cancer Network: 1989-2000.

In 1989 the European Breast Cancer Network (EBCN) was established by the first pilot projects for breast cancer screening, co-funded by the Europe Against Cancer programme. We report early performance indicators for these EBCN projects while taking into account their organizational setting. Out of 17 projects in the network, 10 projects from six European countries contributed aggregated data on number of invitations, screening examinations, and breast cancers detected over the period 1989-2000. Results were summarized separately for projects in centralized versus decentralized health care environments. The European Guidelines for quality assurance in mammography screening provided reference values for the performance indicators. The most prominent finding in this study was the higher participation rate in centralized versus decentralized projects (average participation in 1998: 74 versus 33%; P<0.001), whereas the invitation system and screening policy in these projects were similar. Detection rates and characteristics of cancers detected at initial and subsequent screening examinations showed no significant differences between centralized and decentralized projects. Even though early performance indicators for centralized versus decentralized projects were similar, the impact of breast screening on mortality from this disease at the population level will differ since the decentralized projects reach only part of the target population.

Adult↗

PubMedDate not supplied

Measuring performance improvement: total organizational commitment or clinical specialization.

BACKGROUND: Resources for hospitals are limited when they are faced with multiple publicly reported performance measures as tools to assess quality. The leadership in these organizations may choose to focus on 1 or 2 of these outcomes. An alternative approach is that the leadership may commit resources or create conditions that result in improved quality over a broad range of measures. METHODS: We used aggregated data on mortality, length of stay, and obstetrical outcomes from Greater Cleveland Health Quality Choice data to test these theories. We used Pearson correlation analysis to determine of outcomes were correlated with one another. We used repeated-measures ANOVA to determine if an association existed between outcome and time and outcome and hospital. RESULTS: All of the outcomes across all hospitals demonstrate a trend of overall improvement. Both the Pearson and ANOVA result support the hypothesis for the organization-wide approach to quality improvement. CONCLUSIONS: Hospital that make improvements in one clinical area trend to make improvements in others. Hospitals that produce improvements in limited clinical or administrative areas may not have completely adopted CQI into their culture or may not have yet realized the benefits of their organizational commitments, but use some of the concepts to improve quality outcomes.

Humans↗

PubMedDate not supplied

Mapping parish nurse documentation into the nursing interventions classification: a research method.

Mapping, or linking like terms that represent the same concept, is a research method increasingly used for testing the reliability and validity of standardized taxonomies. For mapping to be useful, it is critical that the procedure is reliable. One way to maximize reliability is to develop standardized mapping procedures, or rules to follow when linking the terms. This article will present a standardized mapping procedure method in a study that mapped narrative parish nurse documentation (170 health records, 1607 interactions) into the Nursing Interventions Classification (NIC), yielding an intercoder reliability kappa of 0.92. The mapping process identified conceptual issues in the NIC, which also are presented. Because the NIC is included in the Systematic Nomenclature of Medicine of Clinical Terms (SNOMED CT), these conceptual issues raised data aggregation issues in SNOMED CT. Those issues are also presented.

Humans↗

PubMed2000

Glutathione S-transferase pi gene methylation: the search for a molecular marker of prostatic adenocarcinoma.

Glutathione S-transferase pi gene methylation has recently been described in prostatic adenocarcinoma. Aggregate data on 115 samples studied to date have found an 87% sensitivity and 92% specificity for prostate cancer diagnosis. The current literature about this new marker is herein summarized, and possible molecular mechanisms by which glutathione S-transferase pi may participate in prostatic carcinogenesis are reviewed. The possible clinical implications of this molecular alteration in the diagnosis of prostatic adenocarcinoma are also studied.

Adenocarcinoma↗

PubMed2006

Do prevention interventions reduce HIV risk behaviours among people living with HIV? A meta-analytic review of controlled trials.

OBJECTIVE: To conduct a meta-analytic review of HIV interventions for people living with HIV (PLWH) to determine their overall efficacy in reducing HIV risk behaviours and identify intervention characteristics associated with efficacy. METHODS: Comprehensive searches included electronic databases from 1988 to 2004, hand searches of journals, reference lists of articles, and contacts with researchers. Twelve trials met the stringent selection criteria: randomization or assignment with minimal bias, use of statistical analysis, and assessment of HIV-related behavioural or biologic outcomes at least 3 months after the intervention. Random-effects models were used to aggregate data. RESULTS: Interventions significantly reduced unprotected sex [odds ratio (OR), 0.57; 95% confidence interval (CI) 0.40-0.82] and decreased acquisition of sexually transmitted diseases (OR, 0.20; 95% CI, 0.05-0.73). Non-significant intervention effects were observed for needle sharing (OR, 0.47, 95% CI, 0.13-1.71). As a whole, interventions with the following characteristics significantly reduced sexual risk behaviours: (1) based on behavioural theory; (2) designed to change specifically HIV transmission risk behaviours; (3) delivered by health-care providers or counsellors; (4) delivered to individuals; (5) delivered in an intensive manner; (6) delivered in settings where PLWH receive routine services or medical care; (7) provided skills building, or (8) addressed a myriad of issues related to mental health, medication adherence, and HIV risk behaviour. CONCLUSION: Interventions targeting PWLH are efficacious in reducing unprotected sex and acquisition of sexually transmitted diseases. Efficacious strategies identified in this review should be incorporated into community HIV prevention efforts and further evaluated for effectiveness.

Adult↗

PubMed2007

Source-specific oppositional defiant disorder: comorbidity and risk factors in referred elementary schoolboys.

OBJECTIVE: To examine differences in risk factors and comorbid conditions for oppositional defiant disorder (ODD) symptom groups in a sample of 248 elementary schoolboys (ages 6-10) recruited from 1994 to 1996. METHOD: The boys and their mothers received multiple assessments of cognitive, behavioral, academic, and family functioning, including a clinic-based evaluation in Stony Brook, NY. ODD was defined using four different strategies for aggregating data from mother and teacher reports of DSM-IV symptoms. RESULTS: Source-specific ODD symptom groups had better internal validity and were more differentiated than groups defined using the other strategies. The mother-defined ODD symptom group (ODD/M) had higher levels of maternal detachment than the teacher-defined symptom group (ODD/T), and the ODD/T group had more social problems than the ODD/M group. The classification agreement group (ODD/M + T) evidenced higher levels of sensation-seeking, maternal control, and comorbid symptoms than the ODD/M and ODD/T groups. Controlling for co-occurring attention-deficit/hyperactivity disorder and conduct disorder symptoms altered some of the relationships among ODD, comorbid symptoms, and psychosocial correlates. CONCLUSIONS: Patterns of co-occurring psychiatric symptoms and psychosocial correlates of ODD symptom groups varied depending on the rater(s) used to determine group membership. Results support continued research into source specificity for conceptualizing ODD.

Attention Deficit Disorder with Hyperactivity↗

PubMed2007

A pooled analysis of posttransplant survival following combined heart-liver transplantation.

Because no single center has accumulated a large experience with this complex operation, the effectiveness of combined orthotopic heart transplantation (OHT) and orthotopic liver transplantation (OLT) in achieving long-term survival has been unknown. Cases of OHT-OLT were pooled from a U.S. transplant recipient registry and from previously published literature. Aggregate data from these sources was used for survival analysis. Thirty-six patients having undergone OHT-OLT were listed in the national registry; the one- and five-year patient survival rates of these patients were 88% and 78%, respectively. Many patients remain alive at 8+ years after transplantation. An analysis of the pooled results of previously-published cases estimated a one-year patient survival rate of 84%. In selected disease processes, OHT-OLT can correct underlying metabolic deficiencies. While rarely indicated, OHT-OLT is a successful treatment for patients with end-stage heart and liver disease, with survival comparable to that seen after isolated orthotopic heart or orthotopic liver transplantation.

Adolescent↗

PubMed2006

Linking protein structure and dynamics to catalysis: the role of hydrogen tunnelling.

Early studies of enzyme-catalysed hydride transfer reactions indicated kinetic anomalies that were initially interpreted in the context of a 'tunnelling correction'. An alternate model for tunnelling emerged following studies of the hydrogen atom transfer catalysed by the enzyme soybean lipoxygenase. This invokes full tunnelling of all isotopes of hydrogen, with reaction barriers reflecting the heavy atom, environmental reorganization terms. Using the latter approach, we offer an integration of the aggregate data implicating hydrogen tunnelling in enzymes (i.e. deviations from Swain-Schaad relationships and the semi-classical temperature dependence of the hydrogen isotope effect). The impact of site-specific mutations of enzymes plays a critical role in our understanding of the factors that control tunnelling in enzyme reactions.

Alcohol Dehydrogenase↗

PubMed2003

Scaling laws for the movement of people between locations in a large city.

Large scale simulations of the movements of people in a "virtual" city and their analyses are used to generate insights into understanding the dynamic processes that depend on the interactions between people. Models, based on these interactions, can be used in optimizing traffic flow, slowing the spread of infectious diseases, or predicting the change in cell phone usage in a disaster. We analyzed cumulative and aggregated data generated from the simulated movements of 1.6 x 10(6) individuals in a computer (pseudo-agent-based) model during a typical day in Portland, Oregon. This city is mapped into a graph with 181,206 nodes representing physical locations such as buildings. Connecting edges model individual's flow between nodes. Edge weights are constructed from the daily traffic of individuals moving between locations. The number of edges leaving a node (out-degree), the edge weights (out-traffic), and the edge weights per location (total out-traffic) are fitted well by power-law distributions. The power-law distributions also fit subgraphs based on work, school, and social/recreational activities. The resulting weighted graph is a "small world" and has scaling laws consistent with an underlying hierarchical structure. We also explore the time evolution of the largest connected component and the distribution of the component sizes. We observe a strong linear correlation between the out-degree and total out-traffic distributions and significant levels of clustering. We discuss how these network features can be used to characterize social networks and their relationship to dynamic processes.

Community Networks↗

PubMed2004

The impact of dietary changes among the Inuit of Nunavik (Canada): a socioeconomic assessment of possible public health recommendations dealing with food contamination.

Inuit populations meet a large portion of their food needs by eating country food in which pollutants are concentrated. Despite the fact that they contain pollutants, the consumption of country food has many health, social, economic, and cultural benefits. A risk determination process was set up in order to help regional health authorities of Nunavik to deal with this particular issue. Based on Nunavik health authorities' objectives to encourage the region's inhabitants to change their dietary habits, and on both the risks and the benefits of eating country food, several management options were developed. The options aimed at reducing exposure to contaminants by either substituting certain foods with others that have a lower contaminant content or by store-bought foods. This article aims at assessing the potential economic impact of these risk management options before being implemented. Relevant economic data (aggregate income and monetary outlays for the purchase of food and equipment required for food production by households) were collected and identified to serve as a backdrop for the various replacement scenarios. Results show that household budgets, and the regional economy, are not significantly affected by the replacement of contaminated foods with the purchase of store-bought meat, and even less so if the solution involves replacing contaminated foods with other types of game hunted in the region. When financial support is provided by the state, the households can even gain some monetary benefits. Results show that public health authorities' recommended changes to dietary habits among the Inuit of Nunavik would not necessarily involve economic constraints for Inuit households.

Canada↗

PubMed2005

A new look at the psychometric paradigm of perception of hazards.

The psychometric paradigm has been the most influential model in the field of risk analysis. The "cognitive maps" of hazards produced by the paradigm seem to explain how laypeople perceive the various risks they face. Because most of the studies used aggregated data, analyzed using principal component analysis, it is not known whether the model neglects individual differences in risk perception. There has been much criticism on the fact that few studies have examined individual differences in the cognitive representation of hazards. In order to detect and describe the internal structure of the three-way data, we conducted a three-way component analysis (3MPCA). Data for the present analysis were derived from a mail survey conducted in Switzerland. Participants were asked to judge 9 attributes for 26 hazards. Individual differences in the cognitive representation of hazards were correlated with external variables (e.g., general trust). The results suggest that methods permitting individual differences should be used more frequently and that utilizing different methods could provide greater insight into the cognitive representation of risks.

Adult↗

PubMed1994

The alcohol content of self-report and 'standard' drinks.

A stubborn problem in alcohol epidemiology is that of standardization of unit of measurement. Consistent use of the 'standard drink' in research reports is hampered by difficulties in the assessment of the alcohol content of, particularly, self-reported drinks. Alcohol content of a drink depends on strength of the beverage and volume of the glass or container from which the beverage is taken. Both factors vary considerably between times, regions and individuals. Interview protocols and questionnaires rarely take into account the fact that people consume alcoholic beverages from a large variety of glasses and containers. In the present study the common presumption is tested of equality of alcohol content of standard and self-reported drinks. The test consisted of measuring the amount of wine, fortified wine and spirits people usually pour in the glass typical for the beverage type. The sample was drawn from the general Dutch population in 1985. The results show that on average self-reported drinks taken at home contained more than the presumed standard (10 g per drink). The deviation was highest for spirits (+26%), followed by fortified wines (+14%) and least for wine (+4%). There seemed to be a positive relationship between deviation from 'standard' and strength of the alcoholic beverage. This result is in line with data on the coverage of sales data: aggregate, survey-based spirits consumption shows the lowest coverage of sales. The effect of the difference between actual and presumed content of drinks on estimates of consumption is an overall increase of 7.5%, higher for women (+12%) than for men (+6%). Results are discussed with respect to the use of the concept of 'standard unit' in research protocols and health education campaigns.

Adolescent↗

PubMed1994

Client education experiences in professional nursing practice--a phenomenological perspective.

This paper reports a small-scale phenomenological study of registered nurses' experiences with their client education role. Its purpose was to investigate phenomena associated with actual experiences as they were encountered by participants. A review of the literature provides an overview of client education in terms of its definition and utility, and draws attention to the notion of compliance and the influence of power in health provider-client relationships. Phenomenology offers an appropriate methodological framework for investigating symbolic experiences, and three central concepts are yielded from aggregate data in the form of confirming experiences, disconfirming experiences and educational processes. Findings indicate that nurses' value the uniqueness of the client and, where possible, tend to initiate educational processes that actually empower individuals. However, disconfirming experiences are associated with demands on nurses' work schedules, low client motivation and non-compliance. Physician interjection is also perceived as problematical, resulting in feelings which undermine the nurses' professional integrity, and which lead to a diminished sense of self-worth.

Humans↗

PubMed2005

Pressure ulcers: implementation of evidence-based nursing practice.

AIMS: A 2-year project was carried out to evaluate the use of multi-component, computer-assisted strategies for implementing clinical practice guidelines. This paper describes the implementation of the project and lessons learned. The evaluation and outcomes of implementing clinical practice guidelines to prevent and treat pressure ulcers will be reported in a separate paper. BACKGROUND: The prevalence and incidence rates of pressure ulcers, coupled with the cost of treatment, constitute a substantial burden for our health care system. It is estimated that treating a pressure ulcer can increase nursing time up to 50%, and that treatment costs per ulcer can range from US$10,000 to $86,000, with median costs of $27,000. Although evidence-based guidelines for prevention and optimum treatment of pressure ulcers have been developed, there is little empirical evidence about the effectiveness of implementation strategies. METHOD: The study was conducted across the continuum of care (primary, secondary and tertiary) in a Canadian urban Health Region involving seven health care organizations (acute, home and extended care). Trained surveyors (Registered Nurses) determined the prevalence and incidence of pressure ulcers among patients in these organizations. The use of a computerized decision-support system assisted staff to select optimal, evidence-based care strategies, record information and analyse individual and aggregate data. RESULTS: Evaluation indicated an increase in knowledge relating to pressure ulcer prevention, treatment strategies, resources required, and the role of the interdisciplinary team. Lack of visible senior nurse leadership; time required to acquire computer skills and to implement new guidelines; and difficulties with the computer system were identified as barriers. CONCLUSIONS: There is a need for a comprehensive, supported and sustained approach to implementation of evidence-based practice for pressure ulcer prevention and treatment, greater understanding of organization-specific barriers, and mechanisms for addressing the barriers.

Evidence-Based Medicine↗

PubMed1994

The rational design of highly stable, amphiphilic helical peptides.

A computer algorithm was devised for the evaluation of helical stability of potentially amphiphilic peptide sequences of specified length containing a set number of leucines in the hydrophobic region. All possible combinations of Glu, Lys and Gln in the hydrophilic region are rated using a set of empirical rules for salt bridge formation in alpha-helices, and the sequences which rate the highest are displayed. The rules for salt bridge formation were largely derived from published studies on the effects of salt bridges on helical stability. The algorithm was tested by redesigning a known amphiphilic alpha-helical peptide, alpha 1B or 1, which has been shown to aggregate into four-helix bundles. Comparison of the circular dichroism spectra of two peptides, 2 and 3, to 1 demonstrated that the redesigned peptide with the highest priority score from the algorithm, 2, was more helical when aggregated and slightly more helical as a monomer, whereas the peptide with the low priority score, 3, was somewhat less helical when aggregated and much less helical when monomeric. These results support the design of the algorithm, although conclusions based on aggregation data are complicated by the importance of interhelix contacts in the bundle. Further studies are underway to examine the reliability of the algorithm's predictions regarding the design of other helical peptides.

Algorithms↗

PubMed1985

Pricing and location of physician services in mental health.

Puzzling results of a positive association between the number of physicians per capita and the level of fees for physician services have been reported in the literature. These results may be due to misspecification of econometric models and use of data aggregated across medical specialties. It is hypothesized that the unusual results would not persist with a carefully specified econometric model for a single medical specialty. A general model of pricing and location of physician's services is applied to the market for psychiatrist's services. The results imply that the market for psychiatrist's services operates in a manner consistent with the predictions of the competitive model.

Fees, Medical↗