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PubMed2006

Comparison of smoking, drinking, and marijuana use between students present or absent on the day of a school-based survey.

The aim of this population-based survey was to compare the prevalence of selected risk behaviors between students present or absent on the day of a school-based survey. The study population was a representative sample of all students of secondary schools in the Seychelles (Indian Ocean). Students absent on the day of the survey were traced and requested to complete the same self-administered questionnaire as did present students. Self-reported consumption of cigarettes, alcohol, and marijuana were measured. Of the sample of 1453 eligible students aged 11 to 17 years, 1321 "present students" completed the survey (90.9% participation), 11 refused to answer all questions, and 121 were not present at school. We could trace 105 of the 121 students not present at school on the survey day ("absent students"), and all of them completed the questionnaire over the next 4 weeks. The prevalence of risk behaviors was significantly higher in absent than present students for current smoking and drinking. Inclusion of data from the absent students resulted in a relative increase in the prevalence of the considered behaviors by 3% to 8% as compared to data based on present students only. In conclusion, the prevalence of risk behaviors was higher in absent than present students. Adjusting for data of absent students increased the prevalence estimates in the base population.

Absenteeism↗
PubMed1984

Lifetime productivity of purebred and crossbred cows of Angus and milking shorthorn parentage: weights and scores.

Lifetime productivity of 242 purebred and reciprocal crossbred Angus (A) and Milking Shorthorn (M) cows was studied. Cows were born in the fall during the 5-yr period from 1966 through 1970. Data from each parity, one through six, were analyzed separately by the method of least-squares. The basic statistical model included effects of breed of cow and year of cow birth plus the first-order interaction. Calf weight data were adjusted for effects of sex and calf age. Production stage was included for analyses of cow weights and condition scores. Data from parities seven through 13 were combined in one analysis with the effect of parity added to the model. Appropriate contrasts of estimates of breed means provided estimates of additive, heterotic, maternal and grandmaternal effects. Using pooled averages, crossbred cows were 22.5 kg (5.7%, P less than .01) heavier and .15 condition score units (5.3%, P less than .01) fatter than purebred cows. Condition scores of AM, MA and AA cows were higher (P less than .05) than those of MM cows. Calves from crossbred cows averaged 6.1 and 9.8 kg heavier (4.2 and 4.7%, P less than .01) at 120 and 210 d of age, respectively, than calves from purebred cows. Calves from AM, MA and MM dams were heavier (P less than .05) than those from AA dams. Calf weight at 210 d of age as a percentage of cow weight was used as a measure of efficiency of production. The heterosis contrast was 3.6% (P less than .01), which represented an 8.5% increase of the crossbreds relative to the mean of purebred cows (42.4%).

Animals↗
PubMed1996

Social support and patterns of adjustment to breast cancer.

The effect of marital support and support from other adults on the emotional and physical adjustment of 128 women with breast cancer was examined. Role function and satisfaction with health care also were evaluated as predictors of adjustment. Intact data series were obtained at 7-10 days, at 1, 2, 3, and 6 months, and 1 year postsurgery. Emotional adjustment could be predicted by satisfaction with a spouse's response to interactional and emotional needs and by support from other adults. The relationships were significant at concurrent times, across contiguous times, and predicting from the 7-10 day postsurgical period to both the 6-month and 1-year end points. Physical adjustment was not predicted by support but satisfaction with health care was predictive of perceived overall health status. Functional status in vocational, domestic, and social roles was significantly related to emotional and physical adjustment at all phases with few exceptions.

Adaptation, Psychological↗
PubMed1991

The effects of census undercount adjustment on congressional apportionment.

"This article shows that undercount adjustment [of the 1990 U.S. census] will probably reallocate one [in] three House seats across the states. The adjustment's impact may depend on the method used and the assumptions underlying undercount estimates. Using regression analysis to reduce sampling error in undercount estimates from dual-systems analysis, however, eliminates sensitivity to all but the most extreme changes in assumptions. Generally, adjustment will more likely affect large states than small ones, and large states with proportionately many urban Black and Hispanic residents will likely gain seats at the expense of large states with few such residents."

Americas↗
PubMed2006

Methods for measuring personal costs associated with vision impairment.

PURPOSE: To describe and evaluate the procedures used to collect personal costs associated with vision impairment using diaries. METHODS: Participants with impaired vision (VA < 6/12 or > or = 6/12 with restricted visual fields) were recruited. Twelve-monthly diaries, provided in large print and electronic format (with audio and Braille instruction manuals and personal assistance), were used to record vision-related expenditures grouped under four categories. Two questionnaires were used to collect additional information and to test the validity of the self-reported costs. RESULTS: Of 227 people who consented to participate, 66% (n = 150; 91 females; mean age = 64.8 years) completed > or = 3 monthly diaries. Of the 150 eligible participants, 68% completed the diaries over 12 months, indicating a relatively high completion rate. The median total cost was AUD 2,417 dollars per annum and median values for the four expenditure categories ranged between AUD 206 dollars and AUD 872 dollars per annum. The data were consistent across different months with no significant difference found between any monthly comparison (t-test; p > Bonferroni-adjusted value). Data at 1, 3, and 6 months, extrapolated to annual figures, showed no significant difference from annual total costs, indicating consistency in the data collection periods. A significant association was found between diary data and similar entries in the follow-up questionnaire, confirming the validity of the recorded expenditures (Spearman; p < 0.01). Participants commented that the diary method was useful to obtain personal costs. CONCLUSION: A high response rate was achieved by using diaries and additional assistance methods. The diary provided an accurate and reliable strategy to determine the major personal costs associated with vision impairment.

Aged↗
PubMed2000

Dose-response analyses of experimental cancer data.

Dose-response analysis provides a powerful tool to determine causality from experimental cancer data, estimate low-dose risk, and evaluate mechanistic hypotheses. However, the interpretation of cancer dose-response data can be influenced by how the dose and response terms are characterized. Using the poly-3 quantal response method to adjust for the extensive and early development of lethal lymphomas in butadiene-exposed mice provided a means of obtaining a better representation of dose-response relationships for late-developing tumors induced by this chemical. Fitting a Weibull model to survival-adjusted tumor data for chloroprene and butadiene indicated similar carcinogenic potencies for these chemicals in mice. In conjunction with the rodent toxicity and carcinogenicity studies conducted by the National Toxicology Program, toxicokinetic studies are performed to characterize relationships between exposure and tissue concentrations of parent compound and metabolites. A physiologically based pharmacokinetic model (PBPK) of butadiene dosimetry indicated that differences in carcinogenic response between rats and mice are not simply due to differences in tissue concentrations of epoxybutene, a mutagenic metabolic intermediate. Thus, factors beyond tissue dosimetry of this metabolite must be important in butadiene-induced carcinogenesis. A PBPK model for isoprene indicated that blood concentrations of isoprene epoxides are a better indicator of kidney cancer risk than are measurements of isoprene-exposure concentrations. An evaluation of dose-response relationships for cytotoxicity, regenerative hyperplasia, and tumor induction by trihalomethanes indicates that for this family of chemicals, cell proliferation is not a reliable predictor of tumor response.

Animals↗
PubMed2003

Cost of illness of Alzheimer's disease: how useful are current estimates?

PURPOSE: The goal of this literature review was to determine the validity and policy relevance of recent estimates from many countries of Alzheimer's disease (AD) costs. DESIGN AND METHODS: We searched Medline and other databases for English-language peer-reviewed journals on total, direct, indirect, and per case cost of AD that used 1985-2000 data. We adjusted costs of U.S. studies for inflation. We adjusted non-U.S. studies by that country's medical cost inflation rate and purchasing power parity (PPP). RESULTS: Of 71 studies identified, 21 met all criteria for inclusion. Annual inflation adjusted U.S. total costs of AD varied from $5.6 billion to $88.3 billion. AD total per case (direct and indirect) costs varied from $1,500 to $91,000; indirect/family costs varied from $3,700 to $21,000. Among non-U.S. studies, AD annual adjusted per case costs varied from PPP $2,300 to PPP $30,000. Cost variation was due to diverse study methods, data sources, services included, and lack of clear differentiation between cost of AD and cost of caring for people with AD. IMPLICATIONS: The cost of AD is high, although reliable estimates are not available. Costs are likely to rise given expected demographic shifts in all countries. The widely variable cost estimates call into question the real costs of Alzheimer's disease and their applicability to policy initiatives.

Alzheimer Disease↗
PubMedDate not supplied

Understanding the lives of older women.

AIM: To understand why some women adjust successfully in later life while others, in similar circumstances, become overwhelmed by life and dislike their old age. METHOD: Qualitative data were generated from field notes of participant observation carried out over ten months. In-depth interviews were also carried out with 11 young older and frail older women, aged 60 to 89 years, attending day centres. A grounded theory approach was adopted to collect and analyse participant observation and interview data. FINDINGS: Adjustment in later life occurs regardless of circumstance. Three areas were identified as being the main obstacles for many. These are depression, maintaining intimacy through friends and family, and managing the change process associated with older age. In addition, a core category of searching for meaning was discovered and used to understand how depression, intimacy and managing change affect adjustment in later life. CONCLUSION: Nurses could use their skills and experience of listening carefully to older patients to discover whether they are distressed, and assess whether there is a need for psychological and emotional support. There is a need for more research into carrying out adjustment work with older women who are struggling to enjoy their later years and with older men to discover themes that are relevant to them.

Aged↗
PubMed2003

Validity of reported vaccination coverage in 45 countries.

BACKGROUND: Monitoring and assessment of coverage rates in national health programmes is becoming increasingly important. We aimed to assess the accuracy of officially reported coverage rates of vaccination with diphtheria-tetanus-pertussis vaccine (DTP3), which is commonly used to monitor child health interventions. METHODS: We compared officially reported national data for DTP3 coverage with those from the household Demographic and Health Surveys (DHS) in 45 countries between 1990 and 2000. We adjusted survey data to reflect the number of valid vaccinations (ie, those administered in accordance with the schedule recommended by WHO) using a probit model with sample selection. The model predicted the probability of valid vaccinations for children, including those without documented vaccinations, after correcting for bias from differences between the children with and without documented information on vaccination. We then assessed the extent of survey bias and differences between officially reported data and those from DHS estimates. FINDINGS: Our results suggest that officially reported DTP3 coverage is higher than that reported from household surveys. This size of the difference increases with the rate of reported coverage of DTP3. Results of time-trend analysis show that changes in reported coverage are not correlated with changes reported from household surveys. INTERPRETATION: Although reported data might be the most widely available information for assessment of vaccination coverage, their validity for measuring changes in coverage over time is highly questionable. Household surveys can be used to validate data collected by service providers. Strategies for measurement of the coverage of all health interventions should be grounded in careful assessments of the validity of data derived from various sources.

Child↗
PubMedDate not supplied

Psychometric properties and normative data for the parent version of the diabetes independence survey.

The parent version of the Diabetes Independence Survey measures parents' perceptions of their children's mastery of 38 diabetes self-care skills. The instrument was administered to 648 parents of 622 children with insulin-dependent diabetes mellitus, ages 3 and 18 years, at seven different pediatric medical centers. Data confirming the internal consistency, interrater reliability, construct validity, and concurrent validity of the instrument are presented in this paper. Age-adjusted normative data for total scores on the instrument as well as item-by-item data on the ages at which mastery of each skill was reported by 25%, 50%, and 75% of parents also are discussed. The Diabetes Independence Survey can be used as a reliable, valid, and efficient research tool for assessing the growth and development of diabetes knowledge and skills among children and adolescents, and as a screening instrument and program evaluation tool for clinical purposes.

Adolescent↗
PubMed2005

Reduction in selective under-ascertainment bias in population-based estimates of cancer patient survival by age adjustment.

Selective under-ascertainment of cancer patients by cancer registries may bias population-based estimates of cancer patient survival. As prognosis is strongly age related for many forms of cancer, age adjustment of cancer survival rates, which is primarily used to enhance the validity of comparative analyses between cancer populations, might also effectively reduce this type of bias. We empirically assessed this potential "side-effect" of age adjustment using data from the Finnish Cancer Registry. Analyses of five-year absolute and relative survival for patients diagnosed in 1990-1994, and age adjustment to the age structure of patients diagnosed in 1985-1989, were used as examples. Various patterns of selective under-ascertainment were simulated, and the bias in crude and age adjusted five-year survival rates was compared. Age adjusted estimates were less biased in most scenarios, which may be an additional argument for application of age adjustment in the analysis and reporting of population-based cancer survival rates.

Adolescent↗
PubMed2006

Understanding and reducing variability of SOM neighbourhood structure.

The self-organizing map (SOM) is a nonlinear unsupervised method for vector quantization. In the context of classification and data analysis, the SOM technique highlights the neighbourhood structure between clusters. The correspondence between this clustering and the input proximity is called the topology preservation. We present here a stochastic method based on bootstrapping in order to increase the reliability of the induced neighbourhood structure. Considering the property of topology preservation, a local approach of variability (at an individual level) is preferred to a global one. The resulting (robust) map, called R-map, is more stable relatively to the choice of the sampling method and to the learning options of the SOM algorithm (initialization and order of data presentation). The method consists of selecting one map from a group of several solutions resulting from the same self-organizing map algorithm, but obtained with various inputs. The R-map can be thought of as the map, among the group of solutions, corresponding to the most common interpretation of the data set structure. The R-map is then the representative of a given SOM network, and the R-map ability to adjust the data structure indicates the relevance of the chosen network.

Algorithms↗
PubMed1988

Prenatal detection of cardiovascular malformations by echocardiography: an indication for cytogenetic evaluation.

Prenatal diagnosis of congenital cardiovascular malformations by echocardiography may signal associated chromosome abnormalities. The exact proportion of these associations is not known but is expected to be higher than that with live-birth. To estimate the risk that a fetus with an echocardiographically detected heart defect has an autosomal trisomy or Turner syndrome, we adjusted the known frequency of aneuploidy in live-born infants with congenital cardiovascular malformations by the reported rate of spontaneous abortion, with data from a population-based case-control study of congenital cardiovascular malformations in which 268 cases (12.7%) had both congenital cardiovascular malformations and a chromosome abnormality. Included in the present analysis were 188 aneuploid infants with congenital cardiovascular malformations that would have been detectable by fetal echo. When data are adjusted for the high spontaneous abortion rate of aneuploid fetuses, we estimate that there would have been more than a threefold increase in aneuploidy over the 13% seen at live-birth. Thus cytogenetic analysis is appropriate in a fetus with echo-diagnosed congenital cardiovascular malformations.

Aneuploidy↗
PubMed2004

Kidney Disease Outcomes Quality Initiative (K/DOQI) and the Dialysis Outcomes and Practice Patterns Study (DOPPS): nutrition guidelines, indicators, and practices.

BACKGROUND: Nutritional markers are important predictors of morbidity and mortality in dialysis patients. The Clinical Practice Guidelines for Nutrition in Chronic Renal Failure provides guidelines for assessing nutritional status that were evaluated using data from the Dialysis Outcomes and Practice Patterns Study (DOPPS). METHODS: The level of various nutritional markers (serum albumin, modified subjective global assessment, serum creatinine, normalized protein catabolic rate [nPCR], and body mass index) were described for representative samples of patients and facilities from 7 countries (France, Germany, Italy, Spain, Japan, United Kingdom, and United States) participating in the DOPPS. RESULTS: A strong inverse association was observed between mortality and serum albumin, with a mortality risk 1.38 times higher for patients with serum albumin concentration less than 3.5 g/dL (35 g/L). There were significant differences by country in the proportion of moderately and severely malnourished patients as determined by the modified subjective global assessment score. In the US sample, severely and moderately malnourished patients had a higher mortality risk compared with those not malnourished, 33% and 5% higher, respectively. An inverse relationship exists between serum creatinine concentration and mortality, with a mortality risk 60% to 70% higher in the lowest quartile group compared with the highest quartile group in Europe and the United States. Levels of nPCR varied significantly between European countries, and there was no association between mortality and nPCR in US data. After adjustment for demographic and comorbidity factors, the mortality risk decreased as body mass index increased in both US and European samples. CONCLUSION: DOPPS data highlight the importance of routine assessment of nutritional status, using multiple parameters, in clinical practice to improve patient care.

Body Mass Index↗
PubMed2006

Using a speech perception neural network computer simulation to contrast neuroanatomic versus neuromodulatory models of auditory hallucinations.

A number of studies suggest that schizophrenia may arise from overzealous pruning of synapses that are an extension of normal developmental pruning during adolescence. Moreover, there has been a long history of studies suggesting that this disorder arises from alterations in the dopaminergic neuromodulatory systems. In order to further assess and compare these two hypotheses, a computer simulation of some aspects of speech perception was developed utilizing a recurrent, backpropagation model of working memory previously reported by Elman . This system was found to produce spontaneous percepts simulating hallucinated speech when the working memory component either was excessively pruned or when neuronal responses were modulated to simulatea hyperdopaminergic system. These hallucinogenic systems also demonstrated disruptions in processing input information when "phonetic information" was degraded. The perceptual performance of these systems were compared to that of actual hallucinating patients and normal controls while tracking (repeating while simultaneously listening to) speech that was phonetically degraded. We found that the neural network simulation producing the best match to speech tracking performance of human hallucinators was an overpruned system with compensatory hypodopaminergic adjustments. These data suggest that the primary pathophysiology of schizophrenia arises from curtailed connectivity in working memory systems and that dopaminergic alterations reflect secondary compensatory adjustments.

Adolescent↗
PubMed1994

Provider perceptions in using outcomes data to improve clinical practice.

In this article we report on the perceptions of health care providers concerning the use of health care outcomes. These perceptions were identified during two afternoon workshops at the symposium on outcomes data held in Keystone, Colorado, in June 1994. The overall goal of these workshops was to explore the potential use of outcomes data within the clinical practice setting. The attitudes and concerns of several key providers formed the framework for the workshop discussions. The strengths and weaknesses associated with using risk-adjusted outcomes data, both to assess and to improve quality of patient care, were debated within the workshop groups. Overall, conference participants agreed that the risk-adjusted outcomes of cardiac care could be used both to assess and to improve the quality of patient care. The research to date, however, represents only a first step toward this goal. The meeting participants challenged the research community to improve on the measures currently available, with the goal of providing clinicians better information to improve the "art" of medicine.

Attitude of Health Personnel↗
PubMed2005

Comparison of radar and raingauge measurements during heavy rainfall.

Five heavy small-scale rainfall events in North Rhine-Westphalia (Germany) were investigated with radar and raingauge data. Special attention was paid to quality check and adjustment of radar data. Attenuation effects could be observed on both, C-Band and on X-Band radar. Adjustment of radar data to raingauge values turned out to be very difficult in the vicinity of heavy local rain cells. For the five affected regions the precipitation was quantified in the form of areal time series and cumulated radar images. As further result of this project, the spatial extent of the precipitation fields was identified and compared with radar and raingauge data.

Environmental Monitoring↗
PubMed2005

Peer victimization and rejection: investigation of an integrative model of effects on emotional, behavioral, and academic adjustment in early adolescence.

This study investigated an integrative model of the effects of peer victimization (PV) and peer rejection (PR) on youth adjustment using data from 508 middle-school students. In the proposed model, PV and PR each contribute independently to problems in emotional, behavioral, and academic adjustment. The adverse consequences of PV and PR are each mediated by their more proximal contributions to lower self-esteem in the form of negative self-evaluations for peer relations and global self-derogation, respectively. Results of structural equation modeling (SEM) analyses provided support for the overall model, including significant indirect linkages of PV and perceived PR with adjustment problems via their intermediary negative associations with lower levels of self-esteem. Additional analyses revealed that indirect linkages of victimization and perceived rejection with emotional problems via self-esteem were evident only for girls. Implications of these findings are discussed.

Adaptation, Psychological↗