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Multivariate Models (multivariate + models)
Selected AbstractsDifferences in the measured alcohol content of drinks between black, white and Hispanic men and women in a US national sampleADDICTION, Issue 9 2009William C. Kerr ABSTRACT Aims To measure and describe drink alcohol content differences between Hispanic, non-Hispanic white and non-Hispanic black men and women in the United States. Design A telephone survey re-interview of 397 respondents who participated originally in the 2005 National Alcohol Survey, of whom 306 provided complete information on home drinks. Setting United States. Participants Adults aged 18 years and older from across the United States. Measurements Direct measurement by respondents of simulated drink pours in respondents' own glassware using a provided beaker and reported beverage brands were used to calculate drink alcohol content. Findings Black men were found to have the largest overall mean drink alcohol content at 0.79 oz (23 ml) of alcohol. This was significantly larger than the mean for white men or for black women and added 30% to black men's monthly alcohol intake when applied to their reported number of drinks. Spirits drinks were found to be particularly large for men. Multivariate models indicated that drink alcohol content differences are attributable more to income and family structure differences than to unmeasured cultural factors tied to race or ethnicity per se. Models predicting alcohol-related consequences and dependence indicate that adjusting drink alcohol content improves model fit and reduces differences between race/ethnicity defined groups. Conclusions Differences in drink alcohol content by gender, race/ethnicity and beverage type choice should be considered in comparisons of drinking patterns and alcohol-related outcomes. Observed differences can be explained partially by measured characteristics regarding family structure and income. [source] Family members of people with alcohol or drug dependence: health problems and medical cost compared to family members of people with diabetes and asthmaADDICTION, Issue 2 2009G. Thomas Ray ABSTRACT Aims To compare the medical costs and prevalence of health conditions of family members of people with an alcohol or drug dependence (AODD) diagnosis to family members of people with diabetes and asthma. Setting Kaiser Permanente of Northern California (KPNC). Participants Family members of people diagnosed with AODD between 2002 and 2005, and matched samples of family members of people diagnosed with diabetes and asthma. Measurements Logistic regression was used to determine whether the family members of people with AODD were more likely to be diagnosed with medical conditions than family members of people with diabetes or asthma. Multivariate models were used to compare health services cost and utilization of AODD family members and diabetes and asthma family members. Analyses were for the year before, and 2 years following, initial diagnosis of the index person. Findings In the year before initial diagnosis of the index person, AODD family members were more likely to be diagnosed with substance use disorders, depression and trauma than diabetes or asthma family members. AODD family members had higher total health-care costs than diabetes family members in the year following, and the second year following, the index date ($217 and $293, respectively). AODD family members had higher total health-care costs than asthma family members in the year before, and second year following, the index date ($104 and $269, respectively). Conclusions AODD family members have unique patterns of health conditions compared to the diabetes and asthma family members and have similar, or higher, health-care cost and utilization. [source] Observed and predicted reproduction of Ceriodaphnia dubia exposed to chloride, sulfate, and bicarbonate,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2010Peter J. Lasier Abstract Chronic toxicities of Cl,, SO, and HCO to Ceriodaphnia dubia were evaluated in low- and moderate-hardness waters using a three-brood reproduction test method. Toxicity tests of anion mixtures were used to determine interaction effects and to produce models predicting C. dubia reproduction. Effluents diluted with low- and moderate-hardness waters were tested with animals acclimated to low- and moderate-hardness conditions to evaluate the models and to assess the effects of hardness and acclimation. Sulfate was significantly less toxic than Cl, and HCO in both types of water. Chloride and HCO toxicities were similar in low-hardness water, but HCO was the most toxic in moderate-hardness water. Low acute-to-chronic ratios indicate that toxicities of these anions will decrease quickly with dilution. Hardness significantly reduced Cl, and SO toxicity but had little effect on HCO. Chloride toxicity decreased with an increase in Na+ concentration, and HCO toxicity may have been reduced by the dissolved organic carbon in effluent. Multivariate models using measured anion concentrations in effluents with low to moderate hardness levels provided fairly accurate predictions of reproduction. Determinations of toxicity for several effluents differed significantly depending on the hardness of the dilution water and the hardness of the water used to culture test animals. These results can be used to predict the contribution of elevated anion concentrations to the chronic toxicity of effluents; to identify effluents that are toxic due to contaminants other than Cl,, SO, and HCO; and to provide a basis for chemical substitutions in manufacturing processes. Environ. Toxicol. Chem. 2010;29:347,358. Published 2009 SETAC [source] Costs of community-based public mental health services for older adults: variations related to age and diagnosisINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 12 2006Todd Gilmer Abstract Background Several studies have examined service use among older adults although, to our knowledge, none has examined costs from a systems perspective. This study examined use and costs of mental health services among older adults in San Diego County in order to determine how expenditures and modes of service varied by age cohort and psychiatric diagnosis. Methods Utilization data from San Diego County Adult and Older Adult Mental Health Services (AOAMHS) were used to identify older adults (age,,,60) receiving services in the community during fiscal year 2003,2004. Cost data were derived from detailed examination of cost reports, and Medicaid fee schedules. Trends in demographic and clinical characteristics by six age cohorts were described. Multivariate models were used to estimate the relationships between costs, age, and clinical diagnosis while controlling for other demographic and clinical characteristics. Components of costs were also examined. Results Total expenditures declined from age cohorts 60,64 through ages 85 and over. Expenditures were similar, and greatest, for clients with schizophrenia and bipolar disorder, while outlays were lower for those with major depression, other psychotic disorder, other depression, anxiety, substance use disorder, and cognitive disorders. Clients diagnosed with cognitive disorder had high use of emergency services and little connection to outpatient services. Conclusions Expenditures were related to age and clinical diagnosis. Future efforts should investigate older adults' pathways to care, and should determine whether older adults presenting in emergency services would benefit from a specialized case management program providing linkages to community based resources. Copyright © 2006 John Wiley & Sons, Ltd. [source] Do Muscle Mass, Muscle Density, Strength, and Physical Function Similarly Influence Risk of Hospitalization in Older Adults?JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 8 2009Peggy Mannen Cawthon PhD OBJECTIVES: To examine the association between strength, function, lean mass, muscle density, and risk of hospitalization. DESIGN: Prospective cohort study. SETTING: Two U.S. clinical centers. PARTICIPANTS: Adults aged 70 to 80 (N=3,011) from the Health, Aging and Body Composition Study. MEASUREMENTS: Measurements were of grip strength, knee extension strength, lean mass, walking speed, and chair stand pace. Thigh computed tomography scans assessed muscle area and density (a proxy for muscle fat infiltration). Hospitalizations were confirmed by local review of medical records. Negative binomial regression models estimated incident rate ratios (IRRs) of hospitalization for race- and sex-specific quartiles of each muscle and function parameter separately. Multivariate models adjusted for age, body mass index, health status, and coexisting medical conditions. RESULTS: During an average 4.7 years of follow-up, 1,678 (55.7%) participants experienced one or more hospitalizations. Participants in the lowest quartile of muscle density were more likely to be subsequently hospitalized (multivariate IRR=1.47, 95% confidence interval (CI)=1.24,1.73) than those in the highest quartile. Similarly, participants with the weakest grip strength were at greater risk of hospitalization (multivariate IRR=1.52, 95% CI=1.30,1.78, Q1 vs. Q4). Comparable results were seen for knee strength, walking pace, and chair stands pace. Lean mass and muscle area were not associated with risk of hospitalization. CONCLUSION: Weak strength, poor function, and low muscle density, but not muscle size or lean mass, were associated with greater risk of hospitalization. Interventions to reduce the disease burden associated with sarcopenia should focus on increasing muscle strength and improving physical function rather than simply increasing lean mass. [source] Role of serum cytokines tumour necrosis factor- , and interleukin-6 in the association between body weight and periodontal infectionJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2009Tuomas Saxlin Abstract Aim: To study the role of serum cytokines tumour necrosis factor , (TNF- ,) and interleukin 6 (IL-6) as potential mediators in the association between body weight and periodontal infection among an adult population. Material and Methods: This study was based on a subpopulation of the Health 2000 Health Examination Survey, which included dentate non-diabetic, non-rheumatic subjects, aged between 45 and 64 years, who had never smoked and whose serum levels of TNF- , and IL-6 were analysed and whose periodontal status was clinically determined (effective n=425). The number of teeth with periodontal pockets of 4 mm or more and the number of teeth with periodontal pockets of 6 mm or more were used as outcome variables. Relative risks and 95% confidence intervals were estimated using Poisson regression models. Results: Serum IL-6, but not TNF- , associated with teeth with deepened periodontal pockets. Multivariate models showed that IL-6, but not TNF- ,, could mediate the effect of body weight on periodontium. Conclusion: In this population of non-diabetic and non-rheumatic subjects, who had never smoked, serum IL-6 was associated with periodontal infection. The results suggest that serum IL-6 could be one mediating factor that connects body weight and periodontal infection. [source] Maternal Cohabitation and Child Well-Being Among Kindergarten ChildrenJOURNAL OF MARRIAGE AND FAMILY, Issue 1 2007Julie E. Artis Using data collected from 10,511 kindergarten children and their parents from the Early Childhood Longitudinal Study,Kindergarten Cohort, this study examines child well-being across cohabiting 2-biological-parent families; cohabiting stepfamilies; married stepfamilies; and married 2-biological-parent families. Findings indicate no differences in child well-being for children living in cohabiting stepfamilies and cohabiting 2-biological-parent families. Multivariate models controlling for child characteristics, economic resources, maternal depressive symptoms, stability, and parenting practices show no significant differences across family types in child well-being indicators, with the exception of reading skills. Important factors in explaining the link between cohabitation and child well-being include economic resources, maternal depressive symptoms, and parenting practices. [source] The distribution of heath balds in the Great Smoky Mountains, North Carolina and TennesseeJOURNAL OF VEGETATION SCIENCE, Issue 4 2001Peter S. White White (1982). Abstract. We used remote sensing and a geographic information system to model the distribution of evergreen shrub communities, called ,heath balds', in the Great Smoky Mountains, North Carolina and Tennessee, USA. The 421 heath balds averaged 1.8 ha in size and covered 0.3% of the landscape. They reached their greatest importance on upper slopes (92% had relative slope positions > 80), convex topography (82% occurred on sites with a curvature greater than 2.6), and elevations between 1100 and 1600 m (94% of the balds). Although heath balds were found in old-growth watersheds, the two watersheds with the greatest number of balds burned extensively after logging in the early 1900s. Bald occurrence was positively correlated with burned sites, old growth condition, and a highly acidic rock type. Heath balds showed a striking geographic pattern, with 88.1% of the area of this community found in six watersheds comprising only 35.4% of the study area. Despite similar topography, geology, and history, the eleven other watersheds had only 11.9% of the bald area while comprising 64.4% of the study area. Multivariate models showed that this community occurs on only 0.4 to 9.0% of the seemingly appropriate sites. Once established, this shrub community, with its dense evergreen canopy and thick leaf litter, is resistant to tree invasion. Both forest and shrub communities are stable on sites that are seemingly ideal for heath bald occurrence. [source] Determinants of Early Medical Management of Nausea and Vomiting of PregnancyBIRTH, Issue 1 2009Anaďs Lacasse BSc ABSTRACT: Background: Early medical management of nausea and vomiting during pregnancy is desirable but less than optimal. The aims of this study were to describe the management of nausea and vomiting during the first prenatal visit and to identify the determinants of 1) addressing the subject of nausea and vomiting during pregnancy with the health practitioner and 2) receiving an antiemetic prescription.Methods: A prospective study was conducted of 283 women who reported nausea and vomiting during the first trimester of pregnancy. Women were eligible if they were at least 18 years of age and , 16 weeks' gestation at the time of their first prenatal visit. Participants completed a questionnaire to determine their maternal characteristics, the presence of nausea and vomiting during pregnancy, and its management.Results: Of the 283 study participants, 79 percent reported that the condition was addressed during their first prenatal visit, 52 percent reported being asked about the intensity and severity of their symptoms, and 22 percent reported being questioned about the extent to which it disrupted their daily tasks. Health practitioners prescribed an antiemetic for 27 percent of women and recommended a nonpharmacological method for 14 percent. Multivariate models showed that the severity of the nausea and vomiting, previous use of an antiemetic, and smoking before pregnancy were significantly associated with an increased likelihood of addressing the subject of nausea and vomiting during pregnancy. Variables associated with an increased likelihood of women receiving an antiemetic prescription included nausea and vomiting severity, excessive salivation, previous antiemetic use, and work status.Conclusions: Health practitioners can improve their management of nausea and vomiting during pregnancy based on the available guidelines for treatment and they should address important factors such as symptom severity and work status at the first prenatal visit to assess women's need for antiemetic treatment. (BIRTH 36:1 March 2009) [source] Circulating tumour-associated plasma DNA represents an independent and informative predictor of prostate cancerBJU INTERNATIONAL, Issue 3 2006FELIX K.-H. OBJECTIVE To investigate whether preoperative plasma levels of free DNA can discriminate between men with localized prostate cancer and benign prostatic hyperplasia (BPH). PATIENTS AND METHODS In all, 161 referred patients suspicious for prostate cancer either by an elevated prostate-specific antigen (PSA) level and/or abnormal digital rectal examination (DRE) were included in this prospective study. Peripheral plasma was taken before prostate biopsy and genomic DNA was extracted from the plasma using the a commercial kit and a vacuum chamber. After controlling for age, PSA level, the percentage free/total (f/t) PSA and prostate volume, the median prostate cancer plasma DNA concentration served as diagnostic threshold in uni- and multivariate logistic regression models. Multivariate models were subjected to 200 bootstraps for internal validation and to reduce over-fit bias. RESULTS Subgroups consisted of 142 men with clinically localized prostate cancer and 19 with BPH. The median plasma concentration of cell-free DNA was 267 ng/mL in men with BPH vs 709 ng/mL in men with prostate cancer. In univariate analyses, plasma DNA concentration was a statistically significant and informative predictor (P = 0.032 and predictive accuracy 0.643). In multivariate analyses, it remained statistically significant after controlling for age, tPSA, f/tPSA and prostate volume, increasing the predictive accuracy by 5.6%. CONCLUSIONS Our data suggest that plasma DNA level is a highly accurate and informative predictor in uni- and multivariate models for the presence of prostate cancer on needle biopsy. The predictive accuracy was substantially increased by adding plasma DNA level. However, larger-scale studies are needed to further confirm its clinical impact on prostate cancer detection. [source] Life Stress as a Risk Factor for Postpartum Depression: Current Research and Methodological IssuesCLINICAL PSYCHOLOGY: SCIENCE AND PRACTICE, Issue 1 2000Joel D. Swendsen There is compelling evidence to suggest that acute adverse life events and certain stressors specific to motherhood increase the risk of maternity blues and diagnoses of postpartum depression. Other psychosocial factors that are likely to explain vulnerability to postpartum depression include previous history of depression and the stress-moderating effects of social support and coping responses. This article reviews the emerging empirical literature on stress and postpartum depression and presents a discussion of methodological issues relevant to advancing this area of research. Multivariate models that examine the interplay of these variables are now required to further our understanding of these syndromes. [source] Prospective study of 5-year caries increment among children receiving comprehensive dental care in the New England children's amalgam trialCOMMUNITY DENTISTRY AND ORAL EPIDEMIOLOGY, Issue 1 2009Nancy Nairi Maserejian Abstract,,, Objective:, To measure the 5-year caries increment among high-risk children during their participation in the New England Children's Amalgam Trial (NECAT), and to evaluate sociodemographic factors that may account for any observed disparities. Methods:, NECAT recruited 534 children aged 6,10 with at least two decayed posterior occlusal surfaces from urban Boston and rural Maine. After restoration of baseline caries and application of sealants to sound surfaces, NECAT continued to provide free comprehensive semiannual dental care to participants. The net caries increment of children who completed the 5-year follow-up (n = 429) was calculated and predictors of caries increment were investigated using multivariate negative binomial models. Results:, The majority of children (89%) experienced new caries by the end of the 5-year follow-up. Almost half (45%) had at least one newly decayed surface by the first annual visit. At year 5, the mean number of new decayed teeth was 4.5 ± 3.6 (range 0,25) and surfaces was 6.9 ± 6.5 (range 0,48). Time trends showed a noticeably higher increment rate among older children and young teenagers. Multivariate models showed that age (P < 0.001), number of baseline carious surfaces (P < 0.001), and toothbrushing frequency (<1/day versus ,2/day, P = 0.04) were associated with caries increment. Only 48 children (11%) did not develop new caries. Conclusions:, Despite the receipt of comprehensive semiannual dental care, the vast majority of these high-risk children continued to develop new caries within 5 years. While disparities were observed by age, extent of prior decay, and toothbrushing frequency, no other sociodemographic factors were associated with caries increment, suggesting that the dental care provided during the trial reduced sociodemographic disparities in prior caries experience that were observed at baseline. [source] THE MISSING LINK IN GENERAL DETERRENCE RESEARCH,CRIMINOLOGY, Issue 3 2005GARY KLECK Research on the deterrent effects of punishment falls into two categories: macro-level studies of the impact of aggregate punishment levels on crime rates, and individual-level studies of the impact of perceived punishment levels on self-reported criminal behavior. For policy purposes, however, the missing link,ignored in previous research,is that between aggregate punishment levels and individual perceptions of punishment. This paper addresses whether higher actual punishment levels increase the perceived certainty, severity, or swiftness of punishment. Telephone interviews with 1,500 residents of fifty-four large urban counties were used to measure perceptions of punishment levels, which were then linked to actual punishment levels as measured in official statistics. Hierarchical linear model estimates of multivariate models generally found no detectable impact of actual punishment levels on perceptions of punishment. The findings raise serious questions about deterrence-based rationales for more punitive crime control policies. [source] RESISTING CRIME: THE EFFECTS OF VICTIM ACTION ON THE OUTCOMES OF CRIMESCRIMINOLOGY, Issue 4 2004JONGYEON TARK This study assessed the impact of sixteen types of victim self protection (SP) actions on three types of outcomes of criminal incidents: first, whether the incident resulted in property loss, second, whether it resulted in injury to the victim, and, third, whether it resulted in serious injury. Data on 27, 595 personal contact crime incidents recorded in the National Crime Victimization Survey for the 1992 to 2001 decade were used to estimate multivariate models of crime outcomes with logistic regression. Results indicated that self-protection in general, both forceful and nonforceful, reduced the likelihood of property loss and injury, compared to nonresistance. A variety of mostly forceful tactics, including resistance with a gun, appeared to have the strongest effects in reducing the risk of injury, though some of the findings were unstable due to the small numbers of sample cases. The appearance, in past research, of resistance contributing to injury was found to be largely attributable to confusion concerning the sequence of SP actions and injury. In crimes where both occurred, injury followed SP in only 10 percent of the incidents. Combined with the fact that injuries following resistance are almost always relatively minor, victim resistance appears to be generally a wise course of action. [source] Neural Network Earnings per Share Forecasting Models: A Comparative Analysis of Alternative MethodsDECISION SCIENCES, Issue 2 2004Wei Zhang ABSTRACT In this paper, we present a comparative analysis of the forecasting accuracy of univariate and multivariate linear models that incorporate fundamental accounting variables (i.e., inventory, accounts receivable, and so on) with the forecast accuracy of neural network models. Unique to this study is the focus of our comparison on the multivariate models to examine whether the neural network models incorporating the fundamental accounting variables can generate more accurate forecasts of future earnings than the models assuming a linear combination of these same variables. We investigate four types of models: univariate-linear, multivariate-linear, univariate-neural network, and multivariate-neural network using a sample of 283 firms spanning 41 industries. This study shows that the application of the neural network approach incorporating fundamental accounting variables results in forecasts that are more accurate than linear forecasting models. The results also reveal limitations of the forecasting capacity of investors in the security market when compared to neural network models. [source] The relationship between anxiety disorders and suicide attempts: findings from the National Epidemiologic Survey on Alcohol and Related ConditionsDEPRESSION AND ANXIETY, Issue 9 2010Josh Nepon M.D. Abstract Background: Previous work has suggested that anxiety disorders are associated with suicide attempts. However, many studies have been limited by lack of accounting for factors that could influence this relationship, notably personality disorders. This study aims to examine the relationship between anxiety disorders and suicide attempts, accounting for important comorbidities, in a large nationally representative sample. Methods: Data came from the National Epidemiologic Survey on Alcohol and Related Conditions Wave 2. Face-to-face interviews were conducted with 34,653 adults between 2004 and 2005 in the United States. The relationship between suicide attempts and anxiety disorders (panic disorder, agoraphobia, social phobia, specific phobia, generalized anxiety disorder, posttraumatic stress disorder (PTSD)) was explored using multivariate regression models controlling for sociodemographics, Axis I and Axis II disorders. Results: Among individuals reporting a lifetime history of suicide attempt, over 70% had an anxiety disorder. Even after adjusting for sociodemographic factors, Axis I and Axis II disorders, the presence of an anxiety disorder was significantly associated with having made a suicide attempt (AOR=1.70, 95% confidence interval (CI): 1.40,2.08). Panic disorder (AOR=1.31, 95% CI: 1.06,1.61) and PTSD (AOR=1.81, 95% CI: 1.45,2.26) were independently associated with suicide attempts in multivariate models. Comorbidity of personality disorders with panic disorder (AOR=5.76, 95% CI: 4.58,7.25) and with PTSD (AOR=6.90, 95% CI: 5.41,8.79) demonstrated much stronger associations with suicide attempts over either disorder alone. Conclusion: Anxiety disorders, especially panic disorder and PTSD, are independently associated with suicide attempts. Clinicians need to assess suicidal behavior among patients presenting with anxiety problems. Depression and Anxiety, 2010. © 2010 Wiley-Liss, Inc. [source] Personality traits as prospective predictors of suicide attemptsACTA PSYCHIATRICA SCANDINAVICA, Issue 3 2009S. Yen Objective:, To examine higher order personality factors of negative affectivity (NA) and disinhibition (DIS), as well as lower order facets of impulsivity, as prospective predictors of suicide attempts in a predominantly personality disordered sample. Method:, Data were analyzed from 701 participants of the Collaborative Longitudinal Personality Disorders Study with available follow-up data for up to 7 years. Cox proportional hazards regression analyses was used to examine NA and DIS, and facets of impulsivity (e.g. urgency, lack of perseverance, lack of premeditation and sensation seeking), as prospective predictors of suicide attempts. Results:, NA, DIS and all facets of impulsivity except for sensation seeking were significant in univariate analyses. In multivariate models which included sex, childhood sexual abuse, course of major depressive disorder and substance use disorders, only NA and lack of premeditation remained significant in predicting suicide attempts. DIS and the remaining impulsivity facets were not significant. Conclusion:, NA emerged as a stronger and more robust predictor of suicide attempts than DIS and impulsivity, and warrants greater attention in suicide risk assessment. Distinguishing between facets of impulsivity is important for clinical risk assessment. [source] Health Status among Emergency Department Patients Approximately One Year after Consecutive Disasters in New York CityACADEMIC EMERGENCY MEDICINE, Issue 10 2005William George Fernandez MD Abstract Objectives: Emergency department (ED) patients with disaster-related experiences may present with vague symptoms not clearly linked to the event. In 2001, two disasters in New York City, the World Trade Center disaster (WTCD) and the subsequent American Airlines Flight 587 crash, presented an opportunity to study long-term consequences of cumulative disaster exposure (CDE) on health-related quality of life (HRQOL) among ED patients. Methods: From July 15 to October 30, 2002, a systematic sample of stable, adult patients from two EDs in New York City were enrolled. Participants completed a self-administered questionnaire. The Short Form 36 (SF-36) was used to assess overall health status. Bivariate analyses were conducted to identify individual correlates of worsening health status. Multivariate regression was performed to identify the association between various factors and overall health status, while controlling for relevant sociodemographic variables. Results: Four hundred seventy-one patients (54.6% female) participated. The participation rate was 73.4%. One hundred sixty-one participants (36%) reported direct, indirect, or occupational exposure to the WTCD; 55 (13.3%) had direct, indirect, or occupational exposure to the plane crash; 33 (8.1%) had both exposures. In separate multivariate models, CDE predicted lower SF-36 scores for general health (p < 0.0096), mental health (p < 0.0033), and bodily pain (p < 0.0046). Conclusions: In the year following mass traumatic events, persons with CDE had lower overall health status than those with one or no disaster exposure. Clinicians should consider the impact that traumatic events have on the overall health status of ED patients in the wake of consecutive disasters. [source] Analysis of nest occupancy and nest reproduction in two sympatric raptors: common buzzard Buteo buteo and goshawk Accipiter gentilisECOGRAPHY, Issue 5 2002Oliver Krüger Nest site selection can have important fitness consequences in birds. I analysed the habitat characteristics of 392 nests of two sympatric raptor species (common buzzard Buteo buteo and goshawk Accipiter gentilis) in Germany and their relation to nest occupation rate and nest reproductive success. For common buzzard, multivariate models explained only small proportions of the variance in nest occupation rate and nest reproductive success (13,19%). Important variables related to nest occupation rate were human disturbances, intra- and interspecific neighbour density, the amount of forested area and nest tree crown cover. Variables related to nest site reproductive success also included human disturbance, intra- and interspecific neighbour density and nest tree crown cover as well as nest distance to the nearest forest edge. In contrast, models for the goshawk explained a much higher proportion of the variation in nest occupation rate and nest reproductive success (41,43%). Important variables related to nest occupation rate were the remoteness of the nest site and direct human disturbance. Variables related to nest site reproductive success were remoteness of the nest site and good hunting habitat. Goshawks seem to be more sensitive to human disturbance than buzzards. A multiple discriminant analysis showed that nest site characteristics substantially overlapped between the species and there is a good evidence that competition for optimal nest sites occurs. Thus, buzzards might be constrained by the dominant goshawk in their nest site selection. [source] Effects of body mass, climate, geography, and census area on population density of terrestrial mammalsGLOBAL ECOLOGY, Issue 5 2001Marina Silva Abstract Aim The aim of this study was to investigate the effects of climate, geography, census area and the distribution of body mass on the mass : density relationship in terrestrial mammal populations. Location The areas covered include most major terrestrial biomes including the tropics, savannas, and temperate forests. Method Data on population density and body mass from 827 populations belonging to 330 different terrestrial mammal species were derived from a review of the literature. Results LOWESS and polynomial regression analysis indicated that the overall mass : density relationship on log-log scales was not linear and that the slope of this relationship behaves differently across the range of body mass. Body mass explained between 37 and 67% of the variability in population density depending upon the dietary category or the biome group. We also developed two multivariate models that can explain up to 65% of the variability in population density in terrestrial mammals. We also tested for a confounding effect of census area on the mass : density relationship on log-log scales in terrestrial mammals. Conclusions Our findings support previous studies suggesting that body mass is a major predictor of the variance in population density in terrestrial mammals. We suggest that the non-linearity of the mass : density relationship may result from the fact that the overall distribution of body mass is a mixture of distributions across dietary groups and biomes. In contrast to body mass, our results indicate that climatic and geographical factors have a minor effect on population density. Although census area was closely correlated with body mass, body mass was generally a better predictor of population density than was census area. [source] Mental Illness and Length of Inpatient Stay for Medicaid Recipients with AIDSHEALTH SERVICES RESEARCH, Issue 5 2004Donald R. Hoover Objective. To examine the associations between comorbid mental illness and length of hospital stays (LOS) among Medicaid beneficiaries with AIDS. Data Source and Collection/Study Setting. Merged 1992,1998 Medicaid claims and AIDS surveillance data obtained from the State of New Jersey for adults with ,1 inpatient stay after an AIDS diagnosis from 1992 to 1996. Study Design. Observational study of 6,247 AIDS patients with 24,975 inpatient visits. Severe mental illness (SMI) and other less severe mental illness (OMI) diagnoses at visits were ascertained from ICD,9 Codes. About 4 percent of visits had an SMI diagnosis; 5 percent had an OMI diagnosis; 43 percent did not have a mental illness diagnosis, but were patients who had been identified as having an SMI or OMI history; and 48 percent were from patients with no identified history of mental illness. Principal Findings. The overall mean hospital LOS was 12.7 days. After adjusting for measures of HIV disease severity and health care access in multivariate models, patients presenting with primary and secondary severe mental illness (SMI) diagnoses had ,32 percent and ,11 percent longer LOS, respectively, than did similar patients without a mental illness history (p<0.001 for each). But in these adjusted models of length of stay: (1) diagnosis of OMI was not related to LOS, and (2) in the absence of a mental illness diagnosed at the visit, an identified history of either SMI or OMI was also not related to LOS. In adjusted models of time to readmission for a new visit, current diagnosis of SMI or OMI and in the absences of a current diagnosis, history of SMI or OMI all tended to be associated with quicker readmission. Conclusions. This study finds greater (adjusted) LOS for AIDS patients diagnosed with severe mental illness (but not for those diagnosed with less severe mental comorbidity) at a visit. The effect of acute severe mental illness on hospitalization time may be comparable to that of an acute AIDS opportunistic illness. While previous research raises concerns that mental illness increases LOS by interfering with treatment of HIV conditions, the associations here may simply indicate that extra time is needed to treat severe mental illnesses or arrange for discharge of afflicted patients. [source] Semen quality in fertile US men in relation to geographical area and pesticide exposureINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 1 2006Shanna H. Swan Summary We conducted the first US study to compare semen quality among study centres using standardized methods and strict quality control. We present data on semen quality in partners of 493 pregnant women recruited through prenatal clinics in four US cities during 1999,2001. Sperm concentration, semen volume and motility were determined at the centres and morphology was assessed at a central laboratory. While between-centre differences in sperm morphology and sample volume were small, sperm concentration and motility were significantly reduced in Columbia, MO (MO) relative to men in New York, NY, Minneapolis, MN and Los Angeles, CA; total number of motile sperm was 113 × 106 in MO and 162, 201 and 196 × 106 in CA, MN and NY respectively. Differences among centres remained significant in multivariate models that controlled for abstinence time, semen analysis time, age, race, smoking, history of sexually transmitted disease and recent fever (all p -values <0.01). We hypothesized that poorer sperm concentration and motility in MO men relative to other centres might be related to agricultural pesticides that are commonly used in the mid-west. We investigated this hypothesis by conducting a nested case,control study within the MO cohort. We selected 25 men in this cohort for whom all semen parameters (concentration, % normal morphology and % motile) were low as cases and an equal number of men for whom all semen parameters were within normal limits as controls. We measured metabolites of eight non-persistent, current-use pesticides in urine samples the men had provided at the time of semen collection. Pesticide metabolite levels were elevated in cases compared with controls for the herbicides alachlor and atrazine, and for the insecticide diazinon (2-isopropoxy-4-methyl-pyrimidinol) (p -values for Wilcoxon rank test = 0.0007, 0.012, and 0.0004 for alachlor, atrazine and diazinon respectively). Men with higher levels of alachlor or diazinon were significantly more likely to be cases than men with low levels [odds ratios (OR) = 30.0, 16.7 for alachlor and diazinon respectively], as were men with atrazine over the limit of detection (OR = 11.3). These associations between current-use pesticides and reduced semen quality suggest that agricultural chemicals may have contributed to the reduced semen quality seen in fertile men from mid-Missouri. [source] Are cognitively intact seniors with subjective memory loss more likely to develop dementia?INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 9 2002Philip St John Abstract Background Subjective memory loss (SML) is common in elderly persons. It is not clear if SML predicts the development of dementia. Objectives (1) to determine if SML in those with normal cognition predicts dementia or cognitive impairment without dementia (CIND); (2) to determine if an association is independent of the effect of age, gender and depressive symptoms. Methods Secondary analysis of the Manitoba Study of Health and Aging (MSHA), a population-based prospective study. Data were collected in 1991, and follow-up was done 5 years later. Community-dwelling seniors sampled randomly from a population-based registry in the Canadian province of Manitoba, stratified on age and region. Only those scoring in the normal range of the Modified mini-mental state examination (3MS) were included. Predictor variables were self-reported memory loss, 3MS, Center for epidemiological studies,depression scale (CES-D), age, gender, and education. Outcomes were mortality and cognitive impairment five years later. Results In bivariate analyses, SML was associated with both death and dementia. In multivariate models, SML did not predict mortality. After adjusting for age, gender, and depressive symptoms, SML predicted dementia. However, after adjusting for baseline 3MS score, SML did not predict dementia. Conclusions Memory complaints predict the development of dementia over five years, and clinicians should monitor these persons closely. However, the proportion of persons developing dementia was small, and SML alone is unlikely to be a useful clinical predictor of dementia. Copyright © 2002 John Wiley & Sons, Ltd. [source] Immigration Policy and Employment Conditions of US Immigrants from Mexico, Nicaragua, and the Dominican Republic1INTERNATIONAL MIGRATION, Issue 5 2005Katharine M. Donato ABSTRACT Prior studies suggest that the passage of the Immigration Reform and Control Act (IRCA) in 1986 signalled a deterioration in the labour market conditions of Mexican migrants. In this paper, we examine whether and how labour market conditions worsened for Dominicans and Nicaraguans after 1986, and the extent to which these shifts were comparable to those experienced by Mexicans. Our analysis relies on a new source of data that offers comparable data across the three national origins. We estimate multivariate models that capture the effects of demographic attributes, human and social capital, migration-specific human and social capital, legal status, period of trip, national origin, and other controls on the hourly wages earned by household heads and whether they received cash wages on their last US trip. Models with interaction terms reveal significant pre- and post-1986 wage effects, but few differences in these effects between Mexicans and Dominicans or Nicaraguans. In contrast, group differences appear in the risk of cash receipt of wages. Dominicans and Nicaraguans experienced a greater increase in this risk relative to Mexicans pre- and post-1986. Together, these findings depict a broader, negative impact of IRCA on Latino migrant wages than has been documented elsewhere. [source] From Illegal to Legal: Estimating Previous Illegal Experience among New Legal Immigrants to the United States1INTERNATIONAL MIGRATION REVIEW, Issue 4 2008Guillermina Jasso This paper develops a framework for estimating previous illegal experience among annual cohorts of new legal immigrants to the United States , using public-use administrative microdata alone, survey data alone, and the two jointly , and provides estimates for the FY 1996 cohort of new immigrants, based on both administrative and survey data. Our procedures enable assessment of type of illegal experience, including entry without inspection, visa overstay, and unauthorized employment. We compare our estimates of previous illegal experience to estimates that would be obtained using administrative data alone; examine the extent of previous illegal experience by country of birth, immigrant class of admission, religion, and geographic residence in the United States; and estimate multivariate models of the probability of having previous illegal experience. To further assess origins and destinations, we carry out two kinds of contrasts, comparing formerly illegal new legal immigrants both to fellow immigrants who do not have previous illegal experience and also to the broader unauthorized population, the latter using estimates developed by the U.S. Department of Homeland Security (2002), Passel (2002), and Costanzo et al. (2002). [source] The Poor Outcome of Ischemic Stroke in Very Old People: A Cohort Study of Its DeterminantsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 1 2010Licia Denti MD OBJECTIVES: To assess how much of the excess risk of poor outcome from stroke in people aged 80 and older aging per se explains, independent of other prognostic determinants. DESIGN: Cohort, observational. SETTING: University hospital. PARTICIPANTS: One thousand five hundred fifty-five patients with first-ever ischemic stroke consecutively referred to an in-hospital Clinical Pathway program were studied. MEASUREMENTS: The relationship between age and 1-month outcome (death, disability (modified Rankin Scale 3,5), and poor outcome (modified Rankin Scale 3,6)) was assessed, with adjustment for several prognostic factors. RESULTS: Six hundred twelve patients aged 80 and older showed worse outcome after 1 month than those who were younger, in terms of mortality (19% vs 5%, hazard ratio (HR)=3.85, 95% confidence interval (CI)=2.8,5.4) and disability (51% vs 33%, odds ratio (OR)=3.16, 95% CI=2.5,4.0), although in multivariate models, the adjusted HR for mortality decreased to 1.47 (95% CI=1.0,2.16) and the ORs for disability and poor outcome decreased to 1.76 (95% CI=1.32,2.3.) and 1.83 (95% CI=137,2.43), respectively. Stroke severity, the occurrence of at least one medical complication, and premorbid disability explained most of the risk excess in the oldest-old. CONCLUSION: Stroke outcome is definitely worse in very old people, and most of the excess risk of death and disability is attributable to the higher occurrences of the most-severe clinical stroke syndromes and of medical complications in the acute phase. These represent potential targets for preventive and therapeutical strategies specifically for elderly people. [source] Self-Reported Sleep and Nap Habits and Risk of Falls and Fractures in Older Women: The Study of Osteoporotic FracturesJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 8 2006Katie L. Stone PhD OBJECTIVES: To test the association between self-reported sleep and nap habits and risk of falls and fractures in a large cohort of older women. DESIGN: Study of Osteoporotic Fractures prospective cohort study. SETTING: Clinical centers in Baltimore, Maryland; Minneapolis, Minnesota; Portland, Oregon; and the Monongahela Valley, near Pittsburgh, Pennsylvania. PARTICIPANTS: Eight thousand one hundred one community-dwelling Caucasian women aged 69 and older (mean 77.0). MEASUREMENTS: Sleep and nap habits were assessed using a questionnaire at the fourth clinic visit (1993/94). Fall frequency during the subsequent year was ascertained using tri-annual questionnaire. Incident hip and nonspinal fractures during 6 years of follow-up were confirmed using radiographic reports. RESULTS: Five hundred fifty-three women suffered hip fractures, and 1,938 suffered nonspinal fractures. In multivariate models, women who reported napping daily had significantly higher odds of suffering two or more falls during the subsequent year (odds ratio=1.32, 95% confidence interval (CI)=1.03,1.69) and were more likely to suffer a hip fracture (hazard ratio (HR)=1.33, 95% CI=0.99,1.78) than women who did not nap daily. Those sleeping at least 10 hours per 24 hours had a higher risk of nonspinal fracture than (HR=1.26, 95% CI=1.00,1.58) and a similar but nonsignificant increased risk of hip fracture to (HR=1.43, 95% CI=0.95,2.15) those who reported sleeping between 8 and 9 hours. CONCLUSION: Self-reported long sleep and daily napping are associated with greater risk of falls and fractures in older women. Interventions to improve sleep may reduce their risk of falls and fractures. Future research is needed to determine whether specific sleep disorders contribute to these relationships. [source] Urinary Incontinence and Psychological Distress in Community-Dwelling Older African Americans and WhitesJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 11 2004Hillary R. Bogner MD Objectives: To compare the association between urinary incontinence (UI) and psychological distress in older African Americans and whites. Design: A population-based longitudinal survey. Setting: Continuing participants in a study of community-dwelling adults who were initially living in East Baltimore in 1981. Participants: African Americans and whites aged 50 and older at follow-up interviews performed between 1993 and 1996 for whom complete data were available (n=747). Measurements: Participants were classified as incontinent if any uncontrolled urine loss within the 12 months before the interview was reported. Psychological distress was assessed using the General Health Questionnaire (GHQ). Results: African Americans with UI were more likely to experience psychological distress as measured using the GHQ than were African Americans without UI (unadjusted odds ratio=4.22, 95% confidence interval=1.72,10.39). In multivariate models that controlled for age, sex, education, functional status, cognitive status, and chronic medical conditions, this association remained statistically significant. The association between UI and psychological distress did not achieve statistical significance in whites. Conclusion: The effect of UI on emotional well-being may be greater for African Americans than for whites. [source] Income-Related Differences in the Use of Evidence-Based Therapies in Older Persons with Diabetes Mellitus in For-Profit Managed CareJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 5 2003Arleen F. Brown MD OBJECTIVES: To determine whether income influences evidence-based medication use by older persons with diabetes mellitus in managed care who have the same prescription drug benefit. DESIGN: Observational cohort design with telephone interviews and clinical examinations. SETTING: Managed care provider groups that contract with one large network-model health plan in Los Angeles County. PARTICIPANTS: A random sample of community-dwelling Medicare beneficiaries with diabetes mellitus aged 65 and older covered by the same pharmacy benefit. MEASUREMENTS: Patients reported their sociodemographic and clinical characteristics. Annual household income (,$20,000 or <$20,000) was the primary predictor. The outcome variable was use of evidence-based therapies determined by a review of all current medications brought to the clinical examination. The medications studied included use of any cholesterol-lowering medications, use of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) for cholesterol lowering, aspirin for primary and secondary prevention of cardiovascular disease, and angiotensin-converting enzyme (ACE) inhibitors in those with diabetic nephropathy. The influence of income on evidence-based medication use was adjusted for other patient characteristics. RESULTS: The cohort consisted of 301 persons with diabetes mellitus, of whom 53% had annual household income under $20,000. In unadjusted analyses, there were lower rates of use of all evidence-based therapies and lower rates of statin use for persons with annual income under $20,000 than for higher-income persons. In multivariate models, statin use was observed in 57% of higher-income versus 30% of lower-income respondents with a history of hyperlipidemia (P = .01) and 66% of higher-income versus 29% of lower-income respondents with a history of myocardial infarction (P = .03). There were no differences by income in the rates of aspirin or ACE inhibitor use. CONCLUSION: Among these Medicare managed care beneficiaries with diabetes mellitus, all of whom had the same pharmacy benefit, there were low rates of use of evidence-based therapies overall and substantially lower use of statins by poorer persons. [source] Estimation of multivariate models for time series of possibly different lengthsJOURNAL OF APPLIED ECONOMETRICS, Issue 2 2006Andrew J. Patton We consider the problem of estimating parametric multivariate density models when unequal amounts of data are available on each variable. We focus in particular on the case that the unknown parameter vector may be partitioned into elements relating only to a marginal distribution and elements relating to the copula. In such a case we propose using a multi-stage maximum likelihood estimator (MSMLE) based on all available data rather than the usual one-stage maximum likelihood estimator (1SMLE) based only on the overlapping data. We provide conditions under which the MSMLE is not less asymptotically efficient than the 1SMLE, and we examine the small sample efficiency of the estimators via simulations. The analysis in this paper is motivated by a model of the joint distribution of daily Japanese yen,US dollar and euro,US dollar exchange rates. We find significant evidence of time variation in the conditional copula of these exchange rates, and evidence of greater dependence during extreme events than under the normal distribution. Copyright © 2006 John Wiley & Sons, Ltd. 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