Individual Data (individual + data)

Distribution by Scientific Domains


Selected Abstracts


The Effect of Benefits, Premiums, and Health Risk on Health Plan Choice in the Medicare Program

HEALTH SERVICES RESEARCH, Issue 4p1 2004
Adam Atherly
Objective. To estimate the effect of Medicare+Choice (M+C) plan premiums and benefits and individual beneficiary characteristics on the probability of enrollment in a Medicare+Choice plan. Data Source. Individual data from the Medicare Current Beneficiary Survey were combined with plan-level data from Medicare Compare. Study Design. Health plan choices, including the Medicare+Choice/Fee-for-Service decision and the choice of plan within the M+C sector, were modeled using limited information maximum likelihood nested logit. Principal Findings. Premiums have a significant effect on plan selection, with an estimated out-of-pocket premium elasticity of ,0.134 and an insurer-perspective elasticity of ,4.57. Beneficiaries are responsive to plan characteristics, with prescription drug benefits having the largest marginal effect. Sicker beneficiaries were more likely to choose plans with drug benefits and diabetics were more likely to pick plans with vision coverage. Conclusions. Plan characteristics significantly impact beneficiaries' decisions to enroll in Medicare M+C plans and individuals sort themselves systematically into plans based on individual characteristics. [source]


The Impact of Mandatory Waiting Periods and Parental Consent Laws on the Timing of Abortion and State of Occurrence among Adolescents in Mississippi and South Carolina

JOURNAL OF POLICY ANALYSIS AND MANAGEMENT, Issue 2 2001
Ted Joyce
Individual data on induced abortions from Mississippi and South Carolina are used to examine the effect of parental consent laws and mandatory delay statutes on two outcomes among teens: the point in pregnancy at which the abortion occurs and whether teens obtain abortions in or outside their state of residence. No effect of either law was found on the timing and location of abortion among minors relative to older teens in South Carolina. In Mississippi, however, both laws are associated with an increase in the proportion of abortions performed out of the state and the parental consent statute with later abortions. The conclusion is that Mississippi's 24-hour as compared with South Carolina's one-hour delay requirement, and Mississippi's two-parent as contrasted with South Carolina's one-parent consent statute explain the stronger behavioral response in Mississippi. 2001 by the Association for Public Policy Management and Ananlysis. [source]


Predictors of a sustained virological response in patients with genotype 4 chronic hepatitis C

LIVER INTERNATIONAL, Issue 8 2008
Rita Raafat Gad
Abstract Objectives: To determine the clinical, biological, virological and histological predictive factors associated with a sustained virological response (SVR) to combined interferon therapy among Egyptian patients infected by genotype 4 hepatitis C virus (HCV). Patients and Methods: Individual data from 250 patients with genotype 4 chronic hepatitis C, treated with different regimens of combined interferon, were analysed. The primary end point was SVR defined as undetectable HCV RNA by polymerase chain reaction (PCR) 24 weeks after the end of treatment. Multivariate logistic regression analysis was performed to select the independent prognostic parameters associated with SVR. Results: A sustained virological response was achieved among 137/250 (54.8%) patients. Baseline factors independently and negatively associated with SVR were serum ,-fetoprotein (AFP) level (above 0.3 upper limit of normal) [odds ratio (OR)=0.5, 95% confidence interval (CI): 0.2,0.8], severe fibrosis (Metavir score >F2) (OR=0.4, 95% CI: 0.2,0.8), presence of steatosis (OR=0.5, 95% CI: 0.3,0.97) and standard interferon treatment (OR=0.4, 95% CI: 0.2,0.8). Conclusions: Among genotype 4 chronic hepatitis C patients, severe fibrosis, severe steatosis, treatment with standard interferon and a high serum AFP level were all negatively associated with SVR. Pretreatment serum AFP level should be considered in the routine assessment of factors predictive of a treatment response. [source]


Acute mountain sickness is associated with sleep desaturation at high altitude

RESPIROLOGY, Issue 4 2004
Keith R. BURGESS
Objective: This study was intended to demonstrate a biologically important association between acute mountain sickness (AMS) and sleep disordered breathing. Methodology: A total of 14 subjects (eight males, six females aged 36 10 years) were studied at six different altitudes from sea level to 5050 m over 12 days on a trekking route in the Nepal Himalaya. AMS was quantified by Lake Louise (LL) score. At each altitude, sleep was studied by 13 channel polysomnography (PSG). Resting arterial blood gases (ABG) and exercise SaO2 were measured. Ventilatory responses (VR) were measured at sea level. Individual data were analysed for association at several altitudes and mean data were analysed for association over all altitudes. Results: ABG showed partial acclimatization. For the mean data, there were strong positive correlations between LL score and altitude, and periodic breathing, as expected. Strong negative correlations existed between LL score and PaO2, PaCO2, sleep SaO2 and exercise SaO2, but there was no correlation with sea level VR. There were equally tight correlations between LLs/PaO2 and LL score/sleep SaO2. The individual data showed no significant correlations with LL score at any altitude, probably reflecting the non-steady state nature of the experiment. In addition, mean SaO2 during sleep was similar to minimum exercise SaO2 at each altitude and minimum sleep SaO2 was lower, suggesting that the hypoxic insult during sleep was equivalent to or greater than walking at high altitude. Conclusions: It is concluded that desaturation during sleep has a biologically important association with AMS, and it is speculated that under similar conditions (trekking) it is an important cause of AMS. [source]


The role of sensorimotor impairments in dyslexia: a multiple case study of dyslexic children

DEVELOPMENTAL SCIENCE, Issue 3 2006
Sarah White
This study attempts to investigate the role of sensorimotor impairments in the reading disability that characterizes dyslexia. Twenty-three children with dyslexia were compared to 22 control children, matched for age and non-verbal intelligence, on tasks assessing literacy as well as phonological, visual, auditory and motor abilities. The dyslexic group as a whole were significantly impaired on phonological, but not sensorimotor, tasks. Analysis of individual data suggests that the most common impairments were on phonological and visual stress tasks and the vast majority of dyslexics had one of these two impairments. Furthermore, phonological skill was able to account for variation in literacy skill, to the exclusion of all sensorimotor factors, while neither auditory nor motor skill predicted any variance in phonological skill. Visual stress seems to account for a small proportion of dyslexics, independently of the commonly reported phonological deficit. However, there is little evidence for a causal role of auditory, motor or other visual impairments. [source]


Assessment of different techniques for subcutaneous glucose monitoring in Type 1 diabetic patients during ,real-life' glucose excursions

DIABETIC MEDICINE, Issue 3 2010
J. K. Mader
Diabet. Med. 27, 332,338 (2010) Abstract Aims, To compare the accuracy of two marketed subcutaneous glucose monitoring devices (Guardian RT, GRT; GlucoDay S, GDS) and standard microdialysis (CMA60; MD) in Type 1 diabetic patients. Methods, Seven male Type diabetic patients were investigated over a period of 26 h simulating real-life meal glucose excursions. Catheters of the three systems were inserted into subcutaneous adipose tissue of the abdominal region. For MD, interstitial fluid was sampled at 30- to 60-min intervals for offline glucose determination. Reference samples were taken at 15- to 60-min intervals. All three systems were prospectively calibrated to reference. Median differences, median absolute relative differences (MARD), median absolute differences (MAD), Bland,Altman plot and Clark Error Grid were used to determine accuracy. Results, Bland,Altman analysis indicated a mean glucose difference (2 standard deviations) between reference and interstitial glucose of ,10.5 (41.8) % for GRT, 20.2 (55.9) % for GDS and 6.5 (35.2) % for MD, respectively. Overall MAD (interquartile range) was 1.07 (0.39; 2.04) mmol/l for GRT, 1.59 (0.54; 3.08) mmol/l for GDS and 0.76 (0.26; 1.58) mmol/l for MD. Overall MARD was 15.0 (5.6; 23.4) % (GRT), 19.7 (6.1; 37.6) % (GDS) and 8.7 (4.1; 18.3) % (MD), respectively. Total sensor failure occurred in two subjects using GRT and one subject using GDS. Conclusions, The three investigated technologies had comparable performance. Whereas GRT underestimated actual blood glucose, GDS and MD overestimated blood glucose. Considerable deviations during daily life meal glucose excursions from reference glucose were observed for all three investigated technologies. Present technologies may require further improvement until individual data can lead to direct and automated generation of therapeutic advice in diabetes management. [source]


Does ecological momentary assessment improve cognitive behavioural therapy for binge eating disorder?

EUROPEAN EATING DISORDERS REVIEW, Issue 5 2002
A pilot study
Abstract The purpose of this pilot study was to test whether self-monitoring in CBT could be enhanced in order to improve the identification of proximal antecedents of binge eating in binge eating disorder (BED). CBT was modified by asking participants to monitor all eating intensively through ecological momentary assessment (EMA). A total of 41 females (mean BMI,=,37.9; SD,=,8.2) meeting DSM-IV criteria for BED were randomly assigned to one of two group treatments; CBT (n,=,22) or CBT with EMA (n,=,19). CBT with EMA differed from CBT in that for the first 2 weeks of treatment, participants completed detailed pocket diaries about mood, events, etc., when signalled at random by programmable wristwatches, as well as at all times when eating. All participants completed measures of eating (EDE-Q, TFEQ, EES) and general psychopathology (BDI, RSE) before treatment, at the end of treatment, and at 1-year follow-up. While both treatment groups showed improvement on the outcome variables of interest, the individual data gained via EMA did not significantly enhance standard CBT. Therefore, it is unlikely that further research incorporating EMA as a therapeutic technique within CBT for BED will be compelling. Copyright 2002 John Wiley & Sons, Ltd and Eating Disorders Association. [source]


Interannual changes in sablefish (Anoplopoma fimbria) recruitment in relation to oceanographic conditions within the California Current System

FISHERIES OCEANOGRAPHY, Issue 1 2006
MICHAEL J. SCHIRRIPA
Abstract Sablefish (Anoplopoma fimbria) supports substantial fisheries in both the eastern and western Pacific Oceans. Juvenile recruitment along the west coast of the continental United States has been highly variable over the past three decades. Using a generalized additive model, we demonstrate that physical oceanographic variables within the California Current System have significant effects on sablefish recruitment. Significant relationships were found between juvenile recruitment and northward Ekman transport, eastward Ekman transport, and sea level during key times and at key locations within the habitat of this species. The model explains nearly 70% of the variability in sablefish recruitment between the years 1974 and 2000. The predictive power of the model was demonstrated by refitting without the last 5 yr of data and subsequent prediction of those years. Bootstrap assessments of bias associated with parameter estimates and jackknife-after-bootstrap assessments of the influence of individual data on parameter estimates are presented and discussed. Using this model, it is possible to draw preliminary conclusions concerning year-class strength of cohorts not yet available to the survey gear as well as historic year-class strengths. We discuss changes in zooplankton abundance and shifts in species of copepods associated with fluctuations in the physical variables that appear to have a major influence on sablefish recruitment. [source]


Seasonal mortality and the effect of body size: a review and an empirical test using individual data on brown trout

FUNCTIONAL ECOLOGY, Issue 4 2008
Stephanie M. Carlson
Summary 1,For organisms inhabiting strongly seasonal environments, over-winter mortality is thought to be severe and size-dependent, with larger individuals presumed to survive at a higher rate than smaller conspecifics. Despite the intuitive appeal and prevalence of these ideas in the literature, few studies have formally tested these hypotheses. 2We here tested the support for these two hypotheses in stream-dwelling salmonids. In particular, we combined an empirical study in which we tracked the fate of individually-marked brown trout across multiple seasons and multiple years with a literature review in which we compiled the results of all previous pertinent research in stream-dwelling salmonids. 3We report that over-winter mortality does not consistently exceed mortality during other seasons. This result emerged from both our own research as well as our review of previous research focusing on whether winter survival is lower than survival during other seasons. 4We also report that bigger is not always better in terms of survival. Indeed, bigger is often worse. Again, this result emerged from both our own empirical work as well as the compilation of previous research focusing on the relationship between size and survival. 5We suggest that these results are not entirely unexpected because self-sustaining populations are presumably adapted to the predictable seasonal variation in environmental conditions that they experience. [source]


Wobbles, humps and sudden jumps: a case study of continuity, discontinuity and variability in early language development

INFANT AND CHILD DEVELOPMENT, Issue 1 2007
Marijn van Dijk
Abstract Current individual-based, process-oriented approaches (dynamic systems theory and the microgenetic perspective) have led to an increase of variability-centred studies in the literature. The aim of this article is to propose a technique that incorporates variability in the analysis of the shape of developmental change. This approach is illustrated by the analysis of time serial language data, in particular data on the development of preposition use, collected from four participants. Visual inspection suggests that the development of prepositions-in-contexts shows a characteristic pattern of two phases, corresponding with a discontinuity. Three criteria for testing such discontinuous phase-wise change in individual data are presented and applied to the data. These are: (1) the sub-pattern criterion, (2) the peak criterion and (3) the membership criterion. The analyses rely on bootstrap and resampling procedures based on various null hypotheses. The results show that there are some indications of discontinuity in all participants, although clear inter-individual differences have been found, depending on the criteria used. In the discussion we will address several fundamental issues concerning (dis)continuity and variability in individual-based, process-oriented data sets. Copyright 2007 John Wiley & Sons, Ltd. [source]


Comparison of risk factors for invasive squamous cell carcinoma and adenocarcinoma of the cervix: Collaborative reanalysis of individual data on 8,097 women with squamous cell carcinoma and 1,374 women with adenocarcinoma from 12 epidemiological studies

INTERNATIONAL JOURNAL OF CANCER, Issue 4 2007
Article first published online: 27 NOV 200
Abstract Squamous cell carcinomas account for about 80% of cancers of the uterine cervix, and the majority of the remainder are adenocarcinomas. There is limited evidence on the extent to which these histological types share a common etiology. The International Collaboration of Epidemiological Studies of Cervical Cancer has brought together and combined individual data on 8,097 women with invasive squamous cell carcinoma, 1,374 women with invasive adenocarcinoma and 26,445 women without cervical cancer (controls) from 12 epidemiological studies. Compared to controls, the relative risk of each histological type of invasive cervical cancer was increased with increasing number of sexual partners, younger age at first intercourse, increasing parity, younger age at first full-term pregnancy and increasing duration of oral contraceptive use. Current smoking was associated with a significantly increased risk of squamous cell carcinoma (RR = 1.50, 95% CI: 1.35,1.66) but not of adenocarcinoma (RR = 0.86 (0.70,1.05)), and the difference between the two histological types was statistically significant (case-case comparison p < 0.001). A history of screening (assessed as having had at least one previous nondiagnostic cervical smear) was associated with a reduced risk of both histological types, but the reduction was significantly greater for squamous cell carcinoma than for adenocarcinoma (RR = 0.46 (0.42,0.50) and 0.68 (0.56,0.82), respectively; case,case comparison, p = 0.002). A positive test for cervical high-risk HPV-DNA was a strong risk factor for each histological type, with 74% of squamous cell carcinomas and 78% of adenocarcinomas testing positive for HPV types 16 or 18. Squamous cell and adenocarcinoma of the cervix share most risk factors, with the exception of smoking. 2006 Wiley-Liss, Inc. [source]


Carcinoma of the cervix and tobacco smoking: Collaborative reanalysis of individual data on 13,541 women with carcinoma of the cervix and 23,017 women without carcinoma of the cervix from 23 epidemiological studies,

INTERNATIONAL JOURNAL OF CANCER, Issue 6 2006
Article first published online: 4 OCT 200
Abstract Tobacco smoking has been classified as a cause of cervical cancer, but the effect of different patterns of smoking on risk is unclear. The International Collaboration of Epidemiological Studies of Cervical Cancer has brought together and combined individual data on 13,541 women with and 23,017 women without cervical carcinoma, from 23 epidemiological studies. Relative risks (RRs) and 95% confidence intervals (CIs) of carcinoma of the cervix in relation to tobacco smoking were calculated with stratification by study, age, sexual partners, age at first intercourse, oral contraceptive use and parity. Current smokers had a significantly increased risk of squamous cell carcinoma of the cervix compared to never smokers (RR = 1.60 (95% CI: 1.48,1.73), p<0.001). There was increased risk for past smokers also, though to a lesser extent (RR = 1.12 (1.01,1.25)), and there was no clear trend with time since stopping smoking (p -trend = 0.6). There was no association between smoking and adenocarcinoma of the cervix (RR = 0.89 (0.74,1.06) and 0.89 (0.72,1.10) for current and past smokers respectively), and the differences between the RRs for smoking and squamous cell and adenocarcinoma were statistically significant (current smoking p<0.001 and past smoking p = 0.01). In current smokers, the RR of squamous cell carcinoma increased with increasing number of cigarettes smoked per day and also with younger age at starting smoking (p<0.001 for each trend), but not with duration of smoking (p -trend = 0.3). Eight of the studies had tested women for cervical HPV-DNA, and in analyses restricted to women who tested positive, there was a significantly increased risk in current compared to never smokers for squamous cell carcinoma (RR = 1.95 (1.43,2.65)), but not for adenocarcinoma (RR = 1.06 (0.14,7.96)). In summary, smokers are at an increased risk of squamous cell but not of adenocarcinoma of the cervix. The risk of squamous cell carcinoma increases in current smokers with the number of cigarettes smoked per day and with younger age at starting smoking. 2005 Wiley-Liss, Inc. [source]


Individual response of growing pigs to sulphur amino acid intake

JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1 2008
J. Heger
Summary Two N balance experiments were conducted to study the individual response of growing pigs to limiting amino acid (AA) intake. Series of fifteen diets with increasing concentration of sulphur amino acids (SAA, Expt 1) or methionine in the presence of excess cystine (Expt 2) were fed sequentially to nine pigs during a 15-day experimental period. The concentration of the AA under test ranged from 50% to 140% of the requirement while other essential AA were given in a 25% excess relative to the limiting AA. N retention was related to the limiting AA intake using rectilinear and curvilinear models. In Expt 1, the quadratic-plateau model fitted the individual data significantly better (p = 0.01) than the linear-plateau model. No difference was found between the two models in Expt. 2, presumably due to the sparing effect of excess cystine on methionine utilization. Exponential, saturation kinetics or four-parameter logistic models fitted to data for all pigs showed that their goodness of fit was similar to those of quadratic-plateau or linear-plateau models. Significant differences (p < 0.05) were found between individual plateau values for N retention within each experiment while the slopes of the regression lines did not significantly differ either in Expt 1 (p = 0.07) or Expt 2 (p = 0.45). There was a positive correlation between the slope and plateau values of the linear-plateau model in Expt 1 (r = 0.74, p = 0.02) but no significant correlation was found in Expt 2 (r = ,0.48, p = 0.13). Marginal efficiencies of SAA and methionine utilization derived from the linear-plateau model were 0.43 and 0.65 respectively. Based on linear-plateau and quadratic-plateau models, daily requirements of SAA and methionine for a 50 kg pig were estimated to be 13.0 and 5.9 g and 14.3 and 6.1 g respectively. [source]


Labour market institutions and employment in France

JOURNAL OF APPLIED ECONOMETRICS, Issue 1 2002
Guy Laroque
The purpose of this paper is to use individual data to study how the minimum wage and the welfare system combine to affect employment in France. Using the 1997 Labour Force Survey, we decompose non-employment of married women into three components: voluntary, classical (due to the minimum wage) and ,other' (a residual category). We find that the minimum wage explains close to 15% of non-employment for these women and that the disincentive effects of some welfare policy measures may be large. Our approach also allows us to evaluate various labour and welfare policy experiments in their effects on participation and employment. Copyright 2002 John Wiley & Sons, Ltd. [source]


Risks and responses among the urban poor in India

JOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 8 2003
Paula Kantor
This paper describes the events faced by urban poor households in Lucknow, India and household responses in the face of these events. Using household and individual data collected in 2002 from 12 slum settlements, the authors found that certain events, such as illness and social and religious spending, are more frequent than others and that some groups, characterized by gender of head of household, community and economic status, experience certain event types more than others. It also found that some less frequent events may be very burdensome due to their high severity. Responses to common event types exhibited a pattern. Households reduced consumption, used savings and took loans much more frequently than other options, across event types. Variations in responses were identified by event type and severity and economic status. The results illustrate the need for both protective and promotive interventions to improve livelihood security among the urban poor. Copyright 2003 John Wiley & Sons, Ltd. [source]


Hierarchical related regression for combining aggregate and individual data in studies of socio-economic disease risk factors

JOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES A (STATISTICS IN SOCIETY), Issue 1 2008
Christopher Jackson
Summary., To obtain information about the contribution of individual and area level factors to population health, it is desirable to use both data collected on areas, such as censuses, and on individuals, e.g. survey and cohort data. Recently developed models allow us to carry out simultaneous regressions on related data at the individual and aggregate levels. These can reduce ,ecological bias' that is caused by confounding, model misspecification or lack of information and increase power compared with analysing the data sets singly. We use these methods in an application investigating individual and area level sociodemographic predictors of the risk of hospital admissions for heart and circulatory disease in London. We discuss the practical issues that are encountered in this kind of data synthesis and demonstrate that this modelling framework is sufficiently flexible to incorporate a wide range of sources of data and to answer substantive questions. Our analysis shows that the variations that are observed are mainly attributable to individual level factors rather than the contextual effect of deprivation. [source]


Thresholds for food allergens and their value to different stakeholders

ALLERGY, Issue 5 2008
R. W. R Crevel
Thresholds constitute a critical piece of information in assessing the risk from allergenic foods at both the individual and population levels. Knowledge of the minimum dose that can elicit a reaction is of great interest to all food allergy stakeholders. For allergic individuals and health professionals, individual threshold data can inform allergy management. Population thresholds can help both the food industry and regulatory authorities assess the public health risk and design appropriate food safety objectives to guide risk management. Considerable experience has been gained with the double-blind placebo-controlled food challenge (DBPCFC), but only recently has the technique been adapted to provide data on thresholds. Available data thus vary greatly in quality, with relatively few studies providing the best quality individual data, using the low-dose DBPCFC. Such high quality individual data also form the foundation for population thresholds, but these also require, in addition to an adequate sample size, a good characterization of the tested population in relation to the whole allergic population. Determination of thresholds at both an individual level and at a population level is influenced by many factors. This review describes a low-dose challenge protocol developed as part of the European Community-funded Integrated Project Europrevall, and strongly recommends its wider use so that data are generated that can readily increase the power of existing studies. [source]


Outdoor exposure to airborne polycyclic organic matter and adverse reproductive outcomes: A pilot study

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 3 2001
Zdravko P. Vassilev MD
Abstract Background To investigate the association between outdoor airborne polycyclic organic matter (POM) and adverse reproductive outcomes in New Jersey, we used a cross-sectional design combining air quality data from the USA EPA Cumulative Exposure Project and individual data on pregnancy outcomes from birth and fetal death certificates at the census tract level. Methods After excluding plural births and chromosomal anomalies, 221,406 live births and 1,591 fetal deaths registered in New Jersey during the years of 1990 and 1991 were included. The exposure estimates were derived from modeled average POM concentrations for each census tract in the state. Results After adjustment for potential confounders, the odds ratios (OR) for very low birth weight for the highest exposure compared to the lowest exposure group was 1.31 (95% CI 1.15,1.51); among term births, high POM exposure was associated with low birth weight OR,=,1.31 (95% CI 1.21,1.43), with fetal death OR,=,1.19 (95% CI 1.02,1.39) and with premature birth OR,=,1.25 (95% CI 1.19,1.31). The univariate stratified analyses suggested effect modification of all observed associations by maternal alcohol consumption. Conclusions This study found associations between outdoor exposure to modeled average airborne POM and several adverse pregnancy outcomes. The data and methods utilized in this pilot study may be useful for identifying hazardous air pollutants requiring in-depth investigation. Am. J. Ind. Med. 40:255,262, 2001. 2001 Wiley-Liss, Inc. [source]


Ethnic differences in spatial mobility: the impact of family ties

POPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 4 2009
Aslan Zorlu
Abstract In the last three decades, the population of Amsterdam has been ,coloured' due to immigration flows from abroad and a low outflow rate among these immigrants and their descendants. The question is to what extent differences in the spatial mobility behaviours of migrants and natives are generated by neighbourhood characteristics , including the level of ethnic segregation and family ties? This article examines spatial mobility processes in the Amsterdam population using administrative individual data covering the entire population of the city. The analysis shows that Caribbean (Surinamese and Antillean) migrants have a higher probability of moving to the suburbs while Moroccans and Turks tend to rearrange themselves within the city. The estimates reveal that neighbourhood ,quality' has only a modest impact on the probability of moving, while family ties significantly hamper the out-mobility of all individuals. The impact of family ties is the largest for Turkish and Moroccan migrants. Copyright 2009 John Wiley & Sons, Ltd. [source]


Breastfeeding Rates in Hong Kong: A Comparison of the 1987 and 1997 Birth Cohorts

BIRTH, Issue 3 2002
Gabriel M. Leung MD
ABSTRACT: Background: Low breastfeeding rates are an issue of international public health concern. Anecdotal reports suggest very low breastfeeding rates in Asia, but no population-based studies have been conducted in the region. To determine the secular trend in breastfeeding practice in an Asian postindustrialized metropolitan community, we examined data from two population-based birth cohorts of Hong Kong infants in 1987 and 1997. Methods: Annual population rates of breastfeeding initiation and duration were estimated from the birth cohorts, considering the change in breastfeeding rates over 10 years with correction for sociodemographic and birth characteristics. Factors associated with breastfeeding practice were identified using multivariate logistic regression modeling in a pooled analysis of individual data of both cohorts. Results: Overall, 26.8 percent of mothers initiated breastfeeding in 1987, and the rate increased to 33.5 percent in 1997. The rate would have been 27.4 percent in 1987 if the distributions of method of delivery, birthweight, birth order, maternal age, education, and employment status had been the same as in 1997. Only 7.6 percent of infants remained on the breast for more than 1 month in 1987 compared with 20.4 percent a decade later. Similarly, the rate for breastfeeding more than 3 months increased from 3.9 to 10.3 percent. Total breastfeeding duration was significantly longer in 1997 than 10 years earlier. Conclusions: This is the first systematic report of secular variations of breastfeeding rates in Asia. Hong Kong should set higher but realistic goals for breastfeeding that emphasize both initiation and maintenance. Given the wide latitude for improvement in terms of readily modifiable risk factors, such as smoking and cesarean section, these new goals should focus on improving rates in these targeted groups where breastfeeding rates are lowest. (BIRTH 29:3 September 2002) [source]


Optical aberration measurements in dog and cat eyes: interest & limit

ACTA OPHTHALMOLOGICA, Issue 2008
SG ROSOLEN
Purpose To measure the ocular optical aberrations in dog and cat using a wavefront aberrometer based on Hartmann-Shack technology. Methods Two dogs and one cat were sedated (Medetomidine, 0.1 mg/kg) and their right eye (RE) pupils were artificially dilated (tropicamide). Wavefront aberrations were measured using an irx3 aberrometer (Imagine Eyes, Orsay, France). Prior to each measurement, the eye was aligned with the instrument optical axis by centering both the eye pupil and Purkinje images. The Hartmann-Shack spot images were produced by an array of 1024 microlenses that defined a 7.2x7.2 mm square area in the pupil plane. In preliminary tests, spot image histograms were optimized by adjusting the sensor acquisition time. Wavefront aberrations were then repeatedly measured 10 times in each animal's RE. Spherical defocus, astigmatism and Zernike coefficients up to the 8th order were finally analyzed. Results The optimal acquisition time was 10 ms for all animals, instead of 33 ms when measuring human eyes. Refractive errors could be analyzed in a 6 mm pupil diameter in all cases. The dilated pupil often exceed the sensor area. The average refractive errors in dog #1, dog #2 and the cat were +2.9D(-2.0D)111;-0.8D(-0.8D)126 and +3.3D(-2.1D)98, respectively while their Root Mean Square (RMS) higher-order aberrations amounted to 1.9, 1.1, and 2.1 m RMS respectively. Standard deviation in sphere and cylinder was 1.0D in the cat and less than 0.5D in both dogs. Standard deviation in the higher-order RMS was 0.8 m in the cat and less than 0.5 m in both dogs. The observation of individual data revealed that a significant part of this variability was due to blink-related changes in aberrations. Conclusion Ocular optical aberrations can be easily measured in dog and cat using a Hartmann-Shack aberrometer with reduced image acquisition time. The tested animals had relatively large higher-order wavefront aberrations when compared to date measured in healthy human eyes. Measurement reproducibility was notably affected by tear layer effects. This variability could probably be reduced using a larger sensor area, specific head contention device and artificial tears. This new diagnostic technique is easily feasible without any use of anaesthesia and provides less variability and more detailed information than skiascopy. Wavefront aberrometry could be useful in both research and clinical applications. [source]


Factors associated with variability in response of diabetic macular oedema after intravitreal triamcinolone

CLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 6 2009
MRCOphth, Shaheeda Mohamed MPH
Abstract Purpose:, To identify factors associated with variability in anatomical and functional response of diabetic macular oedema (DMO) after 4 mg of intravitreal triamcinolone acetonide (ivTA), and for recurrence of macular oedema. Design:, Pooled analysis of individual data from two randomized controlled trials. Methods:, This was a multicentre study involving 107 eyes with DMO administered 4 mg ivTA. Predictive factors for response to treatment were evaluated with linear regression analysis. Factors associated with time to recurrence of oedema were studied with Cox proportional hazards modelling. Main outcome measures were maximum improvement in optical coherence tomography (OCT)-measured central foveal thickness (CFT) and best-corrected visual acuity (BCVA), final CFT and BCVA at 12 months and time to oedema recurrence. Results:, Greater reduction of retinal thickening occurred in eyes with worse baseline thickening (P < 0.001). There was also greater improvement of visual acuity in eyes with poorer preoperative BCVA levels (P < 0.001). Age, duration of oedema and previous macular laser treatment had no significant effect on maximal BCVA or CFT improvement. Eyes given 4 mg triamcinolone alone were more likely to develop recurrence of oedema at 12 months than those given a combination of 4 mg triamcinolone plus sequential laser (hazard ratio 2.60 [95% confidence interval: 1.45,4.67]). Conclusion:, Baseline OCT-measured retinal thickening and BCVA are important predictors of maximal anatomical and functional response of DMO to ivTA, respectively. Combination treatment strategy using sequential laser therapy may have a role in delaying recurrence of oedema after triamcinolone. [source]


Speed, Accuracy, and Serial Order in Sequence Production

COGNITIVE SCIENCE - A MULTIDISCIPLINARY JOURNAL, Issue 1 2007
Peter Q. Pfordresher
The production of complex sequences like music or speech requires the rapid and temporally precise production of events (e.g., notes and chords), often at fast rates. Memory retrieval in these circumstances may rely on the simultaneous activation of both the current event and the surrounding context (Lashley, 1951). We describe an extension to a model of incremental retrieval in sequence production (Palmer & Pfordresher, 2003) that incorporates this logic to predict overall error rates and speed,accuracy trade-offs, as well as types of serial ordering errors. The model,assumes that retrieval of the current event is influenced by activations of surrounding events. Activations of surrounding events increase over time, such that both the accessibility of distant events and overall accuracy increases at slower production rates. The model's predictions were tested in an experiment in which pianists performed unfamiliar music at 8 different tempi. Model fits to speed,accuracy data and to serial ordering errors support model predictions. Parameter fits to individual data further suggest that working memory contributes to the retrieval of serial order and overall accuracy is influenced in addition by motor dexterity and domain-specific skill. [source]


Within-individual discrimination on the Concealed Information Test using dynamic mixture modeling

PSYCHOPHYSIOLOGY, Issue 2 2009
Izumi Matsuda
Abstract Whether an examinee has information about a crime is determined by the Concealed Information Test based on autonomic differences between the crime-related item and other control items. Multivariate quantitative statistical methods have been proposed for this determination. However, these require specific databases of responses, which are problematic for field application. Alternative methods, using only an individual's data, are preferable, but traditionally such within-individual approaches have limitations because of small data sample size. The present study proposes a new within-individual judgment method, the hidden Markov discrimination method, in which time series-data are modeled with dynamic mixture distributions. This method was applied to experimental data and showed sufficient potential in discriminating guilty from innocent examinees in a mock theft experiment compared with performance of previous methods. [source]