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PubMed1991

Interinstitutional comparison of performance in breast fine-needle aspiration cytology. A Q-probe quality indicator study.

In 1989, the College of American Pathologists, Northfield, Ill, instituted a voluntary quality assurance program, called "Q-Probes," that utilized nationwide interinstitutional peer comparison. One of the anatomic pathology modules retrospectively assessed performance in fine-needle aspiration cytology (FNAC) of the breast from cytohistologic correlations that were made in 294 institutions by 988 pathologists on their own cases that were accessioned during a 6-month period. Of the 13,066 cases of FNAC, 10,751 (82%) were satisfactory for evaluation. Of these satisfactory aspirates, 3471 cases (33%) had histologic correlation, which formed the basis for determining diagnostic accuracy. Of breast aspirates, 2254 (17%) were unsatisfactory for evaluation, with the mean frequency of unsatisfactory aspirates obtained by nonpathologists (18%), ie, more than twice that of unsatisfactory aspirates obtained by pathologists (7.2%). In the diagnosis of breast cancer by FNAC, the following performance results were derived with the use of the aggregate data: 82% sensitivity of the FNAC procedure, 97% sensitivity of diagnosis, 97% specificity, 95% positive predictive value, 86% negative predictive value, and 90% efficiency. No significant difference in performance was detected when institutions were stratified by six peer group characteristics. We made the following conclusions: (1) the aggregate and median breast FNAC performance values obtained from this interinstitutional comparison of data from routine procedures performed in diverse settings in North America compared very favorably with performance from single institutions published in studies of similar design in the literature, and (2) these data may provide a reference point for participant institutions to measure future quality improvement in fine-needle aspiration of breast.

Biopsy, Needle↗

PubMed2006

Coupling between carbon cycling and climate in a high-elevation, subalpine forest: a model-data fusion analysis.

Fundamental questions exist about the effects of climate on terrestrial net ecosystem CO(2) exchange (NEE), despite a rapidly growing body of flux observations. One strategy to clarify ecosystem climate-carbon interactions is to partition NEE into its component fluxes, gross ecosystem CO(2) exchange (GEE) and ecosystem respiration (R (E)), and evaluate the responses to climate of each component flux. We separated observed NEE into optimized estimates of GEE and R (E) using an ecosystem process model combined with 6 years of continuous flux data from the Niwot Ridge AmeriFlux site. In order to gain further insight into the processes underlying NEE, we partitioned R (E) into its components: heterotrophic (R (H)) and autotrophic (R (A)) respiration. We were successful in separating GEE and R (E), but less successful in accurately partitioning R (E) into R (A) and R (H). Our failure in the latter was due to a lack of adequate contrasts in the assimilated data set to distinguish between R (A) and R (H). We performed most model runs at a twice-daily time step. Optimizing on daily-aggregated data severely degraded the model's ability to separate GEE and R (E). However, we gained little benefit from using a half-hourly time step. The model-data fusion showed that most of the interannual variability in NEE was due to variability in GEE, and not R (E). In contrast to several previous studies in other ecosystems, we found that longer growing seasons at Niwot Ridge were correlated with less net CO(2) uptake, due to a decrease of available snow-melt water during the late springtime photosynthetic period. Warmer springtime temperatures resulted in increased net CO(2) uptake only if adequate moisture was available; when warmer springtime conditions led into mid-summer drought, the annual net uptake declined.

Altitude↗

PubMed1992

Aprotinin can inhibit the proteolytic activity of thrombin. A fluorescence and an enzymatic study.

Aprotinin has been shown to reduce blood loss and blood requirement when administered prior to surgery and this therapeutic benefit appears to be related to its specificity as a protease inhibitor. The inhibition of plasmin by aprotinin is well characterized, but little is known of its effect on thrombin. In preliminary experiments, we showed that aprotinin can prevent platelet aggregation induced by thrombin. Follow-up studies have now been performed in order to clarify the effect of aprotinin on thrombin. A fluorescence study of the direct binding of aprotinin to human alpha-thrombin was analysed according to the Michaelis-Menten model and a dissociation constant of 30 x 10(-6) mol.l-1 was determined. Aprotinin can displace p-aminobenzamidine, a fluorescent-probe molecule which binds to the active site of serine proteases, showing that the active site of thrombin was involved. Aprotinin also inhibited the ability of thrombin to induce a fibrin clot from purified fibrinogen and to induce the hydrolysis of the chromogenic substrate H-D-phenylalanylpipecolylarginine-p-nitroanalidehydrochloride++ + (S-2238). With S-2238, double-reciprocal plots show that the inhibition is competitive with a Ki of 61 microM and a Km of 1.72 microM. Aprotinin was a potent inhibitor of thrombin-induced aggregation. A Schild plot of the aggregation data yielded a slope of 0.97 +/- 0.12 and an apparent dissociation constant of 57.0 +/- 13.1 microM (mean +/- SEM). Thus, the inhibition of thrombin-induced platelet aggregation by aprotinin fits a model of competitive inhibition. Conclusions are that, in addition to a possible direct effect of aprotinin on platelets, the inhibition of thrombin-induced platelet activation by aprotinin can be also explained, in part, by a direct effect of the inhibitor on the thrombin molecule itself. This supports the concept that a proteolytic step is involved in the platelet response to thrombin. Finally, evidence is in favour of the participation of Trp245 in the fluorescence response of thrombin on binding to aprotinin.

Aprotinin↗

PubMed2005

General practitioners prefer prescribing indicators based on detailed information on individual patients: a Delphi study.

OBJECTIVE: To assess the face validity of both simple and advanced quality indicators for prescribing in general practice. METHODS: In a three-round Delphi study, 100 randomly selected general practitioners (GPs) in Denmark rated 18 indicators for prescribing of non-steroidal anti-inflammatory drugs. All indicators were based on prescription register data and focused on different prescribing aspects. Advanced indicators contained information at the patient level, viz. age, sex and history of drug use, while simple indicators only used drug statistics at practice level. Indicators were rated on a nine-point Likert scale. Consensus among GPs was defined as interquartile ranges of three or less. A median rating of 7-9 was interpreted as face validity and a median rating of 1-3 as no face validity. RESULTS: Participation in the study was accepted by 44 GPs and 37 completed all three rounds. Three indicators based on patient level data and focusing on adverse effects were assessed to have face value. One indicator focusing on costs and based on practice level data was considered unsuitable for evaluating the quality of prescribing. Consensus was not reached for the remaining indicators. CONCLUSIONS: GPs do not regard simple indicators based on aggregated data at practice level as suitable for evaluating the prescribing quality in general practice, but prefer indicators that rest on clinical data at the patient level.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1973

Protection of privacy and confidentiality.

A multistate, cooperative program seeking to develop better methods for the effective and efficient gathering. storing, analyzing, and utilizing of mental patient records has made a comprehensive effort to protect the confidentiality and privacy of these psychiatric patient records. Administrative, technical, and legal safeguards have been implemented. The discussion of legal safeguards involves two areas: the protection of the system itself, located at Rockland State Hospital; and the specific legal environment of confidentiality and privacy of mental health records and information in the group of cooperating jurisdictions. On the whole, adequate legal and administrative protection can be afforded the confidentiality and privacy of an electronic data system in the mental health field, and access to the records can be restricted for the welfare of the patients. At the same time, access to aggregate data in the system can be allowed, under proper standards, for important research and planning purposes. The methods adopted by MSIS to preserve confidentiality and privacy by limiting access to such records could well prove an important model for the development of protective methods in other electronic data programs-not only those in psychiatry, but those in other fields where the data collected are sensitive and confidential.

Ethics, Medical↗

PubMed2005

The use of routinely collected computer data for research in primary care: opportunities and challenges.

INTRODUCTION: Routinely collected primary care data has underpinned research that has helped define primary care as a specialty. In the early years of the discipline, data were collected manually, but digital data collection now makes large volumes of data readily available. Primary care informatics is emerging as an academic discipline for the scientific study of how to harness these data. This paper reviews how data are stored in primary care computer systems; current use of large primary care research databases; and, the opportunities and challenges for using routinely collected primary care data in research. OPPORTUNITIES: (1) Growing volumes of routinely recorded data. (2) Improving data quality. (3) Technological progress enabling large datasets to be processed. (4) The potential to link clinical data in family practice with other data including genetic databases. (5) An established body of know-how within the international health informatics community. CHALLENGES: (1) Research methods for working with large primary care datasets are limited. (2) How to infer meaning from data. (3) Pace of change in medicine and technology. (4) Integrating systems where there is often no reliable unique identifier and between health (person-based records) and social care (care-based records-e.g. child protection). (5) Achieving appropriate levels of information security, confidentiality, and privacy. CONCLUSION: Routinely collected primary care computer data, aggregated into large databases, is used for audit, quality improvement, health service planning, epidemiological study and research. However, gaps exist in the literature about how to find relevant data, select appropriate research methods and ensure that the correct inferences are drawn.

Biomedical Research↗

PubMed2004

Deprived children or deprived neighbourhoods? A public health approach to the investigation of links between deprivation and injury risk with specific reference to child road safety in Devon County, UK.

BACKGROUND: Worldwide, injuries from road traffic collisions are a rapidly growing problem in terms of morbidity and mortality. The UK has amongst the worst records in Europe with regard to child pedestrian safety. A traditional view holds that resources should be directed towards training child pedestrians. In order to reduce socio-economic differentials in child pedestrian casualty rates it is suggested that these should be directed at deprived children. This paper seeks to question whether analysis of extant routinely collected data supports this view. METHODS: Routine administrative data on road collisions has been used. A deprivation measure has been assigned to the location where a collision was reported, and the home postcode of the casualty. Aggregate data was analysed using a number of epidemiological models, concentrating on the Generalised Linear Mixed Model. RESULTS: This study confirms evidence suggesting a link between increasing deprivation and increasing casualty involvement of child pedestrians. However, suggestions are made that it may be necessary to control for the urban nature of an area where collisions occur. More importantly, the question is raised as to whether the casualty rate is more closely associated with deprivation measures of the ward in which the collision occurred than with the deprivation measures of the home address of the child. CONCLUSION: Conclusions have to be drawn with great caution. Limitations in the utility of the officially collected data are apparent, but the implication is that the deprivation measures of the area around the collision is a more important determinant of socio-economic differentials in casualty rates than the deprivation measures of the casualties' home location. Whilst this result must be treated with caution, if confirmed by individual level case-controlled studies this would have a strong implication for the most appropriate interventions.

Accidents, Traffic↗

PubMed2000

Health outcomes among Hispanic subgroups: data from the National Health Interview Survey, 1992-95.

BACKGROUND: Within the next 50 years, Hispanics will become the largest minority group in the United States. The largest Hispanic subgroups are those of Mexican, Cuban, and Puerto Rican descent. The Hispanic population is heterogeneous in terms of culture, history, socioeconomic status (SES) and health status. In this report, various health status measures are compared across Hispanic subgroups in the United States. METHODS: National Health Interview Survey (NHIS) data aggregated from 1992 through 1995 were analyzed. NHIS is one of the few national surveys that has a sufficiently large sample size to adequately compare the different subgroups. Data are presented for four Hispanic origin subgroups--Mexican, Cuban, Puerto Rican, and "other Hispanic" persons--for the Hispanic population as a whole and for the non-Hispanic white and non-Hispanic black populations. These groups are compared with respect to several health status outcomes, providing both age-adjusted and unadjusted estimates. RESULTS: The health indicators for Puerto Rican persons are significantly worse than for the other Hispanic origin subgroups. For example, about 21% of Puerto Rican persons reported having an activity limitation, compared with about 15% of Cuban and Mexican persons and 14% of "other Hispanic" persons. In contrast, the health indicators of Cuban persons are often better than those of the other subgroups. For example, Cuban persons reported an average of 3 days per year lost from school or work, compared with about 6 days for Mexican and Puerto Rican persons and 7 days for "other Hispanic" persons. Mexican persons fare better than Puerto Rican persons on measures such as restricted activity days, bed disability days and hospitalizations. CONCLUSION: These data demonstrate clear differences in health status as well as indicators of socioeconomic status across Hispanic subgroups in the United States. Data on Hispanic subgroups facilitate the planning of public health services for various underserved populations.

Adolescent↗

PubMed1997

Recommended framework for presenting injury mortality data.

Injuries are a substantial and preventable public health problem and account for approximately 6% of deaths in the United States. Many injury epidemiology and injury control programs depend on injury mortality and morbidity data aggregated by external cause of injury codes (E codes) for program planning and evaluation. This report provides a framework for the uniform tabulation and analysis of injury mortality data classified by the Ninth Revision of the International Classification of Diseases (ICD-9) (a subsequent report will address the application of this framework to injury morbidity data). Standard ICD-9 E-code groupings are presented in the form of a matrix and are depicted as mechanism by intent of injury. All cells in the matrix are mutually exclusive. Injury mortality data from the National Center for Health Statistics (NCHS) are presented in the matrix for 1993 to illustrate numbers of deaths within each cell Justifications are given for assigning E codes to major categories and subcategories within the matrix. The groupings of external causes presented in this framework were developed by CDC (National Center for Injury Prevention and Control [NCIPC] and NCHS) in collaboration with members of the American Public Health Association's Injury Control and Emergency Health Services Section (ICEHS). These groupings are intended to assist persons involved in planning and evaluating injury control programs at national, state, and local levels and are relevant for all persons who collect, code, analyze, and report injury data. Public health researchers and other public health professionals are encouraged to adopt or adapt these groupings as a minimum framework for tabulating injury deaths and death rates. For historical continuity, vital statistics programs will continue to use tabulation standards based on both the guidelines of the World Health Organization and derivative lists developed by CDC (NCHS) for presentation of national mortality statistics. The proposed framework can be used to supplement these tabulation standards by providing more detailed presentations of injury deaths and death rates, which are useful for making policy decisions and planning injury prevention activities.

Cause of Death↗

PubMed2004

Flexible meta-regression functions for modeling aggregate dose-response data, with an application to alcohol and mortality.

In this paper, the authors describe fractional polynomials and cubic splines with which to represent smooth dose-response relations in summarizing meta-analytical aggregate data. Use of these two curve-fitting families can help prevent the problems arising from inappropriate linearity assumptions. These methods are illustrated in the problem of estimating the shape of the dose-response curve between alcohol consumption and all-cause mortality risk. The authors considered aggregate data from 29 cohort studies investigating this issue (1966-2000). J-shaped curves with a nadir at approximately 5-7 g/day of alcohol consumption and a last protective dose of 47-60 g/day were consistently obtained from fractional polynomials and cubic splines. The authors conclude that both of the curve-fitting families are useful tools with which to explore dose-response epidemiologic questions by means of meta-analytical approaches, especially when important nonlinearity is anticipated.

Alcohol Drinking↗

PubMed1988

An ordinal multivariate analysis of accident counts as functions of traffic approach volumes at intersections.

This research is concerned with the statistical analysis of accident counts at nonsignalized intersections. The objective is to develop a method for determining general (nonlinear) relationships between approach volumes and accident counts. The method must accommodate the testing of whether intersections of differing physical designs have higher or lower rates of accidents than predicted by traffic levels. It is assumed that only aggregate data are available: (1) counts of total accidents by type (e.g., injury versus property damage) without details concerning the locational position(s) of the vehicle(s) involved; and (2) aggregate traffic intensity on each intersection entry without details concerning turning volumes. The method involves the application of nonlinear multivariate methods to variables treated as ordinal scales. A case study application involving four-leg and three-leg ("T") nonsignalized major arterial intersections in the Netherlands is described. The effect of bicycle traffic on accident rates is included in the case study analysis. The results indicate that there are three groups of each of the two types of intersections based on traffic flow patterns. For each group, a different functional form was found to relate accident rates and specific variables measuring traffic volumes. There were no significant differences among the physical design categories of the intersections in each group that were not accounted for by differences in traffic intensities.

Accidents, Traffic↗

PubMed2005

Are simple feedback interventions involving workplace data associated with better working environment and health? A cluster randomized controlled study among Swedish VDU workers.

OBJECTIVE: To test whether feedback and discussion of ergonomic and psychosocial working environment data during 1 short session with individual, groups, or supervisors of VDU workers had effects on (1) the quality of implemented modifications in workplace design, working technique, or psychosocial aspects; (2) psychological demands, decision latitude, and social support; (3) comfort during computer work, emotional stress, and prevalence of musculoskeletal symptoms or eye discomfort. METHODS: Thirty-six workgroups from 9 organizations were randomized to 3 feedback conditions (individual, workgroup, supervisor) or control. Follow-up was 6 months after intervention. Questionnaire data aggregated on the workgroup level were used. RESULTS: Effect (positive) on social support was indicated from feedback to supervisors. CONCLUSION: Feedback and discussion of ergonomic and psychosocial working environment data with supervisors of white-collar VDU workers may have positive effect on social support measured as a group characteristic. Sources of potential bias are discussed.

Adult↗

PubMed2006

Beyond the data deluge: data integration and bio-ontologies.

Biomedical research is increasingly a data-driven science. New technologies support the generation of genome-scale data sets of sequences, sequence variants, transcripts, and proteins; genetic elements underpinning understanding of biomedicine and disease. Information systems designed to manage these data, and the functional insights (biological knowledge) that come from the analysis of these data, are critical to mining large, heterogeneous data sets for new biologically relevant patterns, to generating hypotheses for experimental validation, and ultimately, to building models of how biological systems work. Bio-ontologies have an essential role in supporting two key approaches to effective interpretation of genome-scale data sets: data integration and comparative genomics. To date, bio-ontologies such as the Gene Ontology have been used primarily in community genome databases as structured controlled terminologies and as data aggregators. In this paper we use the Gene Ontology (GO) and the Mouse Genome Informatics (MGI) database as use cases to illustrate the impact of bio-ontologies on data integration and for comparative genomics. Despite the profound impact ontologies are having on the digital categorization of biological knowledge, new biomedical research and the expanding and changing nature of biological information have limited the development of bio-ontologies to support dynamic reasoning for knowledge discovery.

Animals↗

PubMedDate not supplied

[Epidemiology of HIV infection in Italy].

AIDS surveillance systems, which have provided for many years useful information on HIV epidemic dynamics, are no longer useful for estimating the evolution of the HIV epidemic due to the effect of anti-retroviral treatments that have strongly improved survival of HIV-infected persons. To obtain reliable data on the HIV epidemic, some Italian provinces and regions (Lazio, Veneto, Friuli Venezia-Giulia, Trento, Modena) have set up local surveillance systems of the new HIV diagnoses. Aggregated data collected by these systems since 1988, show that the rapid spread of the infection in the eighties has been followed by a progressive decrease in the number of new diagnoses during the nineties; in more recent years this trend has levelled-off. The composition of cases by exposure category has greatly changed over time: in 1988 75.2% of cases were injecting drug users, whereas in 2000 58.5% of cases acquired the infection through sexual contacts. HIV incidence for the considered areas decreased from 19.2 per 100.000 inhabitants in 1992, to 6.7 per 100.000 inhabitants in 2000. Median age at diagnosis increased over time, from 27 years in 1988 to 34 years in 2000. The changed pattern of the HIV epidemic in Italy stresses the need of a nation-wide surveillance system for HIV infections aimed at allocation of adequate economic resources and planning specific prevention programmes.

Adult↗

PubMed1990

Data base management system for assisted reproduction.

A substantial amount of data are generated from a single cycle of in vitro fertilization (IVF), gamete intrafallopian transfer (GIFT), or related techniques. Maintaining an accurate and timely record of the flow of information is complicated by provision of service to many patients concurrently, diverse origins of data, and the use of donor sperm, donor oocytes, and/or cryopreservation. We have developed a data base management system for use on a network of personal computers that takes into account the volume, intricacy, and specialized features of data generated by IVF and GIFT programs. The major products of the system are (1) compact, individual patient reports on virtually all details of each treatment cycle; (2) reports on aggregate data (e.g., monthly, quarterly, or yearly); (3) automated summaries for submission to the American Fertility Society National Registry; and (4) creation of raw data files of user-specified variables that could be used for statistical analysis.

Database Management Systems↗

PubMed2005

Scan-rate-dependent melting transitions of interleukin-1 receptor (type II): elucidation of meaningful thermodynamic and kinetic parameters of aggregation acquired from DSC simulations.

The role of thermal unfolding as it pertains to thermodynamic properties of proteins and their stability has been the subject of study for more than 50 years. Moreover, exactly how the unfolding properties of a given protein system may influence the kinetics of aggregation has not been fully characterized. In the study of recombinant human Interleukin-1 receptor type II (rhuIL-1R(II)) aggregation, data obtained from size exclusion chromatography and differential scanning calorimetry (DSC) were used to model the thermodynamic and kinetic properties of irreversible denaturation. A break from linearity in the initial aggregation rates as a function of 1/T was observed in the vicinity of the melting transition temperature (T(m) approximately 53.5 degrees C), suggesting significant involvement of protein unfolding in the reaction pathway. A scan-rate dependence in the DSC experiment testifies to the nonequilibrium influences of the aggregation process. A mechanistic model was developed to extract meaningful thermodynamic and kinetic parameters from an irreversibly denatured process. The model was used to simulate how unfolding properties could be used to predict aggregation rates at different temperatures above and below the T(m) and to account for concentration dependence of reaction rates. The model was shown to uniquely identify the thermodynamic parameters DeltaC(P) (1.3 +/- 0.7 kcal/mol-K), DeltaH(m) (74.3 +/- 6.8 kcal/mol), and T(m) with reasonable variances.

Calorimetry, Differential Scanning↗

PubMed2006

Profile of ovarian cancer patients seeking information from a web-based decision support program.

BACKGROUND: There is limited information available regarding the characteristics of patients who elect to gather and share information about their malignancy on the Internet. METHODS: Using a proprietary decision support program embedded into a number of established websites, individuals entered personal clinical data into disease site profilers designed to provide information about evidence-based treatment options, based on specific characteristics (e.g., stage of disease, prior therapy) provided by the patients. The aggregate data were evaluated to examine the characteristics of patients with gynecological cancer (with a focus on newly diagnosed and recurrent ovarian cancer) using such a tool. RESULTS: From early 2000 through November 2004, >15,000 patients with gynecological cancer have entered data into one of four profilers: newly diagnosed (n = 5604)/recurrent (n = 2803) ovarian, endometrial, and cervical cancers. Internal data consistency includes similar ages and general health histories of the ovarian and endometrial cancer populations and younger age of the cervical cancer patients. Whereas 90% of the women with ovarian cancer considered themselves to be in "good health," 64% of newly diagnosed vs. only 50% of recurrent disease patients declared their activity level was "normal." Of the recurrent patients, 32% stated they had undergone a secondary surgery. The overall aggressive management philosophy of the recurrent patients in this series is supported by the observation that 33% had received > or =4 prior chemotherapy regimens, 97% desired additional treatment, and 81% were interested in clinical trials. CONCLUSIONS: Women with ovarian cancer seeking assistance from web-based decision support programs may represent a subgroup with unique clinical features compared with the general patient population.

Adult↗

PubMed2001

Small area estimation of incidence of cancer around a known source of exposure with fine resolution data.

OBJECTIVES: To describe the small area system developed in Finland. To illustrate the use of the system with analyses of incidence of lung cancer around an asbestos mine. To compare the performance of different spatial statistical models when applied to sparse data. METHODS: In the small area system, cancer and population data are available by sex, age, and socioeconomic status in adjacent "pixels", squares of size 0.5 km x 0.5 km. The study area was partitioned into sub-areas based on estimated exposure. The original data at the pixel level were used in a spatial random field model. For comparison, standardised incidence ratios were estimated, and full bayesian and empirical bayesian models were fitted to aggregated data. Incidence of lung cancer around a former asbestos mine was used as an illustration. RESULTS: The spatial random field model, which has been used in former small area studies, did not converge with present fine resolution data. The number of neighbouring pixels used in smoothing had to be enlarged, and informative distributions for hyperparameters were used to stabilise the unobserved random field. The ordered spatial random field model gave lower estimates than the Poisson model. When one of the three effects of area were fixed, the model gave similar estimates with a narrower interval than the Poisson model. CONCLUSIONS: The use of fine resolution data and socioeconomic status as a means of controlling for confounding related to lifestyle is useful when estimating risk of cancer around point sources. However, better statistical methods are needed for spatial modelling of fine resolution data.

Adolescent↗