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 343 records · Page 19Linked to original sources

PubMed1982

Health as an unobservable: a MIMIC-model of demand for health care.

This paper develops a model to analyze the demand for health care. It differs from current practice in that (1) it deals explicitly with the complex relation between income, health, health insurance, and the demand for health care, and (2) 'health' is treated as an unobservable variable. We present the Maximum Likelihood estimates of an eleven-equation, simultaneous multiple-indicator, multiple-causes (MIMIC) model, containing two simultaneously determined unobservables and, in total, nine 'indicators'. Data used stem from a health-care survey among 8000 households in The Netherlands. The results show, among other things, that health and permanent income have mutual, positive impacts. Both age and education have important direct and indirect (via permanent income) effects on health. The estimated impact of the availability of health care on individual demand confirms similar results based on aggregated data.

Family↗

PubMed2004

Fertility awareness-based methods for contraception.

BACKGROUND: "Fertility awareness-based methods" (FAB) of family planning "involve identification of the fertile days of the menstrual cycle, whether by observing fertility signs such as cervical secretions and basal body temperature, or by monitoring cycle days. FAB methods can be used in combination with abstinence or barrier methods during the fertile time" (WHO 2000). Several names have been used to describe this approach to contraception, including "rhythm," "natural family planning" and "periodic abstinence." Fertility awareness-based methods can be used with abstinence from sexual intercourse. Alternatively, they can be used with barrier contraceptives or withdrawal during presumed fertile times. OBJECTIVES: We retrieved and analyzed all randomized controlled trials that examined any fertility awareness-based methods used for contraception. SEARCH STRATEGY: We searched the computerized databases Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, POPLINE, EMBASE, and LILACS (each from its inception to January, 2004) for randomized controlled trials of fertility awareness-based methods. We examined the reference list of each trial as well as that of review articles. SELECTION CRITERIA: We included all randomized controlled trials in any language that compared any fertility awareness-based methods for contraception with a placebo; another method, including an alternative fertility awareness-based method; or fertility awareness-based methods used in conjunction with another contraceptive. DATA COLLECTION AND ANALYSIS: We assessed all titles and abstracts found for inclusion. We evaluated the methodological quality of the trials for potential biases by qualitatively assessing the study design; randomization method; allocation concealment; blinding; premature discontinuation rates; and loss to follow-up rates. Because of methodological weaknesses, we could not enter the trial results in RevMan, calculate measures of association, or aggregate data. MAIN RESULTS: Because of poor methods and reporting, pregnancy rates could not be determined. A trial in Colombia found similar numbers of pregnancies among women randomized to the ovulation and symptothermal methods. In contrast, a companion trial in Los Angeles observed more pregnancies in the group assigned to the ovulation method. In the two U.S. trials, recruitment of participants was unexpectedly difficult; this aspect was not mentioned in the report from Colombia. Continuation rates were poor. In the two larger trials, most participants discontinued their assigned method before entering the observation phase of the trial. REVIEWERS' CONCLUSIONS: The comparative efficacy of fertility awareness-based methods of contraception remains unknown. Despite intensive training and ongoing support, most participants in these trials discontinued prematurely. Contraceptive methods should be properly evaluated, preferably in randomized controlled trials, before adoption and dissemination.

Awareness↗

PubMedDate not supplied

What follow-up studies say about postschool life for young men and women with learning disabilities: a critical look at the literature.

Follow-up studies examining the outcomes for children and youth with learning disabilities who attended special education have appeared in the literature for decades. As American society becomes more technologically advanced and competitive, postsecondary school opportunities and subsequent employment choices that are meaningful and provide a livable wage teeter out of the reach of young people with learning disabilities. Follow-up study investigators seek to understand how to better prepare youth to meet these challenges by studying their long-term outcomes. The authors review data from 13 frequently referenced follow-up studies regarding postschool outcomes, postsecondary education, and employment, with attention to gender differences, for youth with learning disabilities who were served by and graduated from special education programs nationwide. They take a critical look at contradictions in the findings and discuss five methodological issues that seem to influence the conduct and interpretation of follow-up studies: aggregating data across disability categories; combining data on graduates who have been out of school for unequal periods of time; ignoring the issues of missing data, participant attrition, and incomplete data sets; combining data from different informants; and using nonequivalent databases to make comparisons to a population with no disabilities. The authors provide recommendations for conducting follow-up research on the long-term quality of life of children and youth with disabilities and their families.

Adult↗

PubMed2000

Use of conditional and marginal odds-ratios for analysing familial aggregation of binary data.

We propose a method for measuring familial aggregation of binary outcomes that incorporates unconditional, i.e., marginal, odds-ratios, for measuring association between outcomes within generations while using conditional odds-ratios to measure association between generations. This method may be used together with marginal odds-ratio models to explore the strength of association between individuals within a generation while accounting for the outcomes of predecessors. Interpretation of resulting odds-ratios is straightforward and a number of features of the method are discussed. An example, using smoking status data from Busselton Health Study families, is used to illustrate our approach.

Bias↗

PubMed2006

Approaches to patient health information exchange and their impact on emergency medicine.

Regional health information organizations and electronic health information exchange may have an important impact on the practice of emergency medicine in the United States. Regional health information organizations are local or regional information-sharing networks that enable electronic data interchange among stakeholders in a given geographic area. These stakeholders may include hospitals, skilled nursing facilities, clinics, private physicians' offices, pharmacies, laboratories, radiology facilities, health departments, payers, and possibly the patients themselves. Regional health information organizations are being formed across the country to improve the safety and efficiency of clinical care; improve public health efforts, biosurveillance, and disaster management response; and potentially create large databases of deidentified aggregate data for research. Because of the unique need for rapid access to information and the acuity of the clinical environment, few areas of the health care delivery system stand to change and benefit more from health information exchange than our nation's emergency departments. This article will explain the motivation for the development of regional health information organizations, identify some of the important issues in their formation, and discuss how their development might affect the practice of emergency medicine.

Confidentiality↗

PubMed1996

Evaluating surgically induced astigmatism by Fourier analysis of corneal topography data.

PURPOSE: To evaluate surgically induced astigmatism using Fourier harmonic series analysis of corneal topography data. SETTING: Aarhus Kommunehospital, Aarhus University, Denmark. METHODS: We evaluated the results of 46 phacoemulsifications with a 4 or 6 mm scleral tunnel sutureless incision based on the axis of the steepest meridian. We performed conventional keratometry and corneal topography before and up to 1 month after surgery. Using Fourier analysis, the corneal topographic images were broken into spherical power, regular astigmatism, and nonregular astigmatism for individual or aggregate analysis of surgically induced astigmatism. The induced refractive change (average of the difference between preoperative and postoperative corneal topographies) was analyzed and normalized according to the surgical meridian and to right/left eye. RESULTS: Regular astigmatism calculated by Fourier analysis of mires from the keratometer zone correlated well with conventional keratometry readings. Surgery induced a localized flattening in the superior region and a with-the-rule regular astigmatism component in the central area. CONCLUSION: Surgically induced corneal topography changes can be analyzed by Fourier series harmonic analysis, allowing aggregate data to be broken into optically meaningful quantities.

Adult↗

PubMed2006

Age-related changes in consultations and antibiotic prescribing for acute respiratory infections, 1995-2000. Data from the UK General Practice Research Database.

BACKGROUND: International studies using data aggregated for all ages have shown decreasing rates of general practice consultations for acute respiratory infections with fewer antibiotic prescriptions issued per consultation. The occurrence of different respiratory infections varies widely at different ages but we do not know whether prescribing has reduced equally in all age groups. OBJECTIVE: We aimed to determine how reductions in consultation rates and antibiotic prescribing varied with age for different respiratory infections. METHODS: Data were abstracted from the General Practice Research Database for 108 general practices in the UK (mean registered population 642 685). We estimated age-specific changes between 1995 and 2000 in consultation rates, and the proportion of consultations resulting in an antibiotic prescription for 'all respiratory infections' and for 'sore throat', 'ear infection', 'bronchitis' and 'chest infection'. RESULTS: Consultation rates for 'all respiratory infections' declined in all age groups with the greatest decreases in children aged 1-4 years (41%), 5-10 year olds (53%) and 11-16 year olds (54%), whereas at 75-84 years the reduction was 28%. The pattern of greater reductions in children held for each separate condition even though the age of peak incidence varied. The relative reduction in antibiotic prescribing was greatest at 1-4 years (18%), 5-10 years (17%) and 11-16 years (17%), compared with 5% at 75-84 years. Antibiotic prescribing decreased most for sore throat and this was observed at all ages particularly in 5-10 year olds (relative reduction, 32%). CONCLUSIONS: School age children account for the greatest reduction in consultations for acute respiratory infection. School age and preschool children account for the greatest reductions in antibiotic prescribing during the consultation. The rapid changes in consultation rates are unexplained.

Adolescent↗

PubMed1990

Platelet-activating factor (PAF) inhibitory profile of KO-286011 on blood platelets in vitro and in vivo.

A newly synthesised structural analogue of PAF, coded KO-286011 (1-O-hexadecyl-2-O-ethyl-rac-glycero-3-phosphoric acid 4-(N,N-dimethylamino)pyridinium butylester), was proved for its ability to inhibit PAF-mediated platelet responses in vitro and in vivo. The compound inhibited effectively the PAF-induced aggregation and secretion of human and rabbit platelets. In contrast, there was little influence on ADP-, collagen-, and arachidonic acid-triggered platelet responses. Schild-analysis of aggregation data ascertained in human platelet-rich plasma was consistent with a simple competitive antagonism and yielded a pA2 of 6.44. Proaggregatory activity of KO-286011 was excluded turbidimetrically as well as by means of a single cell counting technique. [3H]PAF binding studies provided evidence that KO-286011 exerts its inhibitory action at the PAF-receptor level. A significant inhibition of the ex vivo PAF-induced platelet aggregation was found after i.v. administration of 0.5 mg/kg KO-286011 to rabbits. The effect was most pronounced 5 min after dosing the inhibitor and detectable over a period of 30 min. Intravenous administration of 10 and 25 micrograms/kg KO-286011 to guinea pigs prevented dose-dependently the PAF-induced formation of thromboxane A2. The PAF-inhibitory action of KO-286011 was more potent than that of the ginkgolide BN 52021.

Animals↗

PubMed1996

The development of patient profiles for Minnesota's treatment outcomes monitoring system.

Minnesota's treatment outcomes monitoring system is a cooperative effort between the State alcohol and drug abuse agency and 366 licensed treatment providers. A minimum dataset is required on all treatment admissions to provide a state-wide system profile. In addition, data are being collected on a sample of 30 patients from each program to measure patient characteristics and severity of problems, patient perceptions of needed assistance, actual nature and amount of services received, patient satisfaction and patient functioning 6 months following discharge from treatment. The dimensions measured include alcohol and other drug use, physical health, psychological well-being, employment and financial status, family and social relationships and criminality. The aggregated data will be analysed to determine what types of services are associated with more favorable outcomes for different types of patients. The findings will be used to develop standards for treatment placement and service delivery based on individual patient profiles. This report provides an overview of the plan and an illustration of how patient profiles can be developed for purposes of treatment service matching and outcomes monitoring.

Adult↗

PubMed2006

U.S. congressional district cancer death rates.

BACKGROUND: Geographic patterns of cancer death rates in the U.S. have customarily been presented by county or aggregated into state economic or health service areas. Herein, we present the geographic patterns of cancer death rates in the U.S. by congressional district. Many congressional districts do not follow state or county boundaries. However, counties are the smallest geographical units for which death rates are available. Thus, a method based on the hierarchical relationship of census geographic units was developed to estimate age-adjusted death rates for congressional districts using data obtained at county level. These rates may be useful in communicating to legislators and policy makers about the cancer burden and potential impact of cancer control in their jurisdictions. RESULTS: Mortality data were obtained from the National Center for Health Statistics (NCHS) for 1990-2001 for 50 states, the District of Columbia, and all counties. We computed annual average age-adjusted death rates for all cancer sites combined, the four major cancers (lung and bronchus, prostate, female breast, and colorectal cancer) and cervical cancer. Cancer death rates varied widely across congressional districts for all cancer sites combined, for the four major cancers, and for cervical cancer. When examined at the national level, broad patterns of mortality by sex, race and region were generally similar with those previously observed based on county and state economic area. CONCLUSION: We developed a method to generate cancer death rates by congressional district using county-level mortality data. Characterizing the cancer burden by congressional district may be useful in promoting cancer control and prevention programs, and persuading legislators to enact new cancer control programs and/or strengthening existing ones. The method can be applied to state legislative districts and other analyses that involve data aggregation from different geographic units.

Age Distribution↗

PubMed2004

Evaluation of the association between hereditary thrombophilias and recurrent pregnancy loss: a meta-analysis.

BACKGROUND: Recurrent pregnancy loss (RPL) is a significant clinical problem. Recently, thrombophilias have been implicated as a possible cause. Factor V Leiden (FVL) and prothrombin gene (G20210A) mutations are the most common types of hereditary thrombophilias, but are usually undiagnosed because most carriers are asymptomatic. The relationship between FVL, G20210A, and RPL has been investigated with conflicting results. This study analyzed existing data to determine whether an association exists. METHODS: A systematic review of the literature was performed. Only case-control studies that defined RPL as 2 or more pregnancy losses in the first or second trimester and that confirmed mutations by DNA analysis were included. Sixteen studies were selected for the FVL meta-analysis and 7 for the G20210A analysis. Stratified and multivariate logistic regression analyses were performed with the use of aggregate data. Results were confirmed by means of fixed- and random-effects meta-analyses models. RESULTS: The combined odds ratios for the association between RPL and FVL and between RPL and G20210A were 2.0 (95% confidence interval, 1.5-2.7; P<.001) and 2.0 (95% confidence interval, 1.0-4.0; P =.03), respectively. Similar results were produced by the logistic regression and both fixed- and random-effects meta-analysis models. CONCLUSIONS: Carriers of FVL or prothrombin gene mutations have double the risk of experiencing 2 or more miscarriages compared with women without thrombophilias. Hereditary thrombophilias may be an unrecognized cause of RPL. We recommend testing for these mutations in women with RPL.

Abortion, Habitual↗

PubMed1995

Searching for answers on a clinical information system.

We examined observational data on the use of a clinical computing system in an effort to develop an empirical model of clinicians' information needs. Clinicians turn to information systems most often to review the results of diagnostic studies. After that, clinicians turn to information systems most often for communication. Bibliographic retrieval is the third most frequent reason for use, but is an order of magnitude less frequent than either results inquiry or electronic mail. Secondary retrieval of aggregate data from a clinical database is two orders of magnitude less common than primary retrieval. In a study at our hospital, clinicians gained access to an information resource during 16% of all general medical visits of patients with human immunodeficiency virus (HIV) infection while the patient was present. Insofar as our narrow focus on the primary care of HIV infection models the larger context of clinical medicine, clinicians are most often looking at information relating to therapeutics. Whatever knowledge structures are adopted, they must accommodate this observed need for therapeutic information.

Diagnosis, Computer-Assisted↗

PubMed1999

Recovery rates in generalized anxiety disorder following psychological therapy: an analysis of clinically significant change in the STAI-T across outcome studies since 1990.

BACKGROUND: There have been six randomized controlled trials of psychological therapy with generalized anxiety disorder (GAD) using DSM-III-R and DSM-IV. All have used the Trait version of the Spielberger State-Trait Anxiety Inventory (STAI-T) as one of several outcome measures. Each study, however, employed different methods of calculating the clinical significance of outcomes making it difficult to reach a balanced appraisal of the efficacy of psychological treatment. METHODS: Raw data on STAI-T scores at pre-, post- and follow-up were obtained for each of the six studies (total N = 404). Jacobson methodology for defining clinically significant change (criterion c, reliable change index = 8, cut-off point = 46) was used to allocate each patient to one of four outcomes: worse, unchanged, improved and recovered. The proportion of patients in each category was calculated for treatment conditions in each study and also for aggregate data across types of treatment. RESULTS: A recovery rate of 40% was found for the sample as a whole with 12 of the 20 treatment conditions obtaining very modest recovery rates of 30% or less. Two treatment approaches--individual cognitive behavioural therapy and applied relaxation--do relatively well with overall recovery rates at 6-month follow-up of 50-60%. CONCLUSIONS: Jacobson methodology, in distinguishing between improvement and recovery on a standardized measure of general vulnerability to anxiety, provides a stringent but clinically more meaningful evaluation of the efficacy of psychological therapies with GAD than has been available hitherto. Systematic focus on either excessive worry or physiological arousal gives worthwhile results.

Anxiety Disorders↗

PubMed1996

Comparison between the Health Belief Model and Subjective Expected Utility Theory: predicting incontinence prevention behaviour in post-partum women.

A small-scale study was undertaken to test the relative predictive power of the Health Belief Model and Subjective Expected Utility Theory for the uptake of a behaviour (pelvic floor exercises) to reduce post-partum urinary incontinence in primigravida females. A structured questionnaire was used to gather data relevant to both models from a sample antenatal and postnatal primigravida women. Questions examined the perceived probability of becoming incontinent, the perceived (dis)utility of incontinence, the perceived probability of pelvic floor exercises preventing future urinary incontinence, the costs and benefits of performing pelvic floor exercises and sources of information and knowledge about incontinence. Multiple regression analysis focused on whether or not respondents intended to perform pelvic floor exercises and the factors influencing their decisions. Aggregated data were analysed to compare the Health Belief Model and Subjective Expected Utility Theory directly.

Adult↗

PubMed1999

Evidence and expertise: the challenge of the outcomes movement to medical professionalism.

The outcomes movement--including evidence-based medicine--challenges medicine as a profession by disputing what and how physicians know. First, the movement considers probabilistic research to be virtually the only way to arrive at knowledge in medicine. Second, it insists on objective or impersonal knowledge (statistically manipulated, hard, aggregate data). Such knowledge does not come from within the professional relationship; rather it is gathered across relationships and is offered to the practitioner from the outside. Third, the outcomes movement is motivated by a desire for certainty, promising definitive solutions that will reduce variation and waste. What professionals know, in contrast, is inherently and irreparably uncertain. Fourth, the movement expects physicians to implement the findings from probabilistic research through application. The inferential leap necessary for treating an individual based on aggregate findings is mostly assumed away. Finally, the outcomes movement promotes rule-based behavior on the part of physicians in an effort, among other things, to eliminate variation in medical practice. But professionals do not follow rules per se--they intuit what is right in a situation, including, sometimes, that it is right to defer to a rule. Professional knowledge in medicine is both larger and smaller than the knowledge conceived of by the outcomes movement. The latter is built of probabilistic research and translated into physician directives. Professional knowledge, in contrast, partakes of statistical knowledge and bench science, as well as various forms of personal knowledge, including the experiential. Physicians will continue to need professional knowledge, which allows for the complexity of physician experience and for the immediacy and individuality of patients.

Clinical Competence↗

PubMed2006

Reducing variation in antibacterial prescribing rates for 'cough/cold' and sore throat between 1993 and 2001: regional analyses using the general practice research database.

OBJECTIVE: To use the General Practice Research Database (GPRD) to explore the regional variation in prescribing for single diagnostic episodes of 'cough/cold' and sore throat and how this changed between 1993 and 2001. METHODS: Data from the GPRD was used to conduct a longitudinal survey of morbidity and antibiotic prescribing data. RESULTS: Nationally there has been a substantial reduction in diagnosed episodes per 1000 patient years at risk for both diagnoses: from 104.6 (104.0-105.2) to 86.5 (86.0-86.9) for cough/cold (-17.3%) and from 102.8 (102.2-103.4) to 69.2 (68.8-69.6) for sore throat (-32.6%). In addition to the changes in diagnostic rate there have been reductions in diagnosis-related prescribing: from 41.8% to 34.8% of cough/cold episodes (-7.0%) and from 77.3% to 60.8% of sore throat episodes (-16.4%). These aggregated data conceal wide regional variations. For cough/cold the change in prescribing rate during the study varied from -16.0% to +5.3% and for sore throat from -28.3% to -7.3%. CONCLUSIONS: In addition to a substantial reduction in diagnosis of cough/cold and sore throat, there has been a reduction in diagnosis-related prescribing episodes in almost all regions. Although there continues to be regional variation in diagnosis-related prescribing this has reduced substantially over the 9-year study period.

Anti-Bacterial Agents↗

PubMed1990

Validation of oral status indicators.

In planning programmes and developing policy, dental public health officials rely on epidemiological data in the form of composite measures such as the DMFT index. However, the DMFT is often not sufficiently sensitive to detect differences in oral health between population groups. Measures that selectively weight components of the DMFT may be better dental indicators. Sheiham, Maizels and Maizels (1987) suggested a functional measure (FM) that weights filled and sound teeth equally and a tissue health (T-health) measure that differentially weights decayed, filled, and sound teeth. For the present analysis, these indicators were divided by 28 to make their range 0 to 1. The modified indexes are called FMI and THI. Carpay et al. (1988) also suggested a dental health index (DHI) that scores a subset of teeth. Data from 797 participants in the 1980 Iowa Survey of Oral Health that included eight independent variables were used to perform stepwise regression on DMFT, FMI, THI, and DHI to assess how well the independent variables correlated with these four dental indicators. R-square values were 0.37 for FMI and 0.36 for THI, but only 0.19 for DHI and 0.12 for DMFT, suggesting that the FMI and THI were more sensitive as dental health indicators. In addition, calculations made on aggregate data published from three national surveys show that the FMI and THI can detect changes in oral health over time. Because the FMI and THI are as easy to measure and calculate as the DMFT, but appear to be more sensitive, they show promise as indicators of oral health status.

Adolescent↗

PubMedDate not supplied

American College Health Association National College Health Assessment (ACHA-NCHA) Spring 2005 Reference Group Data Report (Abridged).

Assessing and understanding the health needs and capacities of college students is paramount to creating healthy campus communities. The American College Health Association-National College Health Assessment (ACHA-NCHA) is a survey instrument developed by the ACHA in 1998 to assist institutions of higher education in achieving this goal. The ACHA-NCHA contains approximately 300 questions assessing student health status and health problems, risk and protective behaviors, access to health information, impediments to academic performance, and perceived norms across a variety of content areas (eg, injury prevention; personal safety and violence; alcohol, tobacco, and other drug use; sexual health; weight, nutrition, and exercise; mental health). Twice a year, the ACHA compiles aggregate data from participating institutions in a reference group report for data comparison. Results from the Spring 2005 Reference Group (N = 54,111) are presented in this article.

Adolescent↗