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PubMed2006

DOVER and QUVER-new marker combinations to detect and monitor at-risk drinking.

BACKGROUND: At-risk drinking is a common medical problem. "Objective" laboratory tests are widely used, especially in situations where it might be favorable for the patient to dissimulate the existing alcohol problem. In this study, we report a new approach to combine the biological markers % carbohydrate-deficient transferrin (%CDT) and gamma-glutamyltransferase (gammaGT) to increase diagnostic properties to identify patients with at-risk drinking behavior. METHODS: Fifty-eight general practitioners (GPs) participated in the study at 2 study sites in South-West Germany. Patients filled in a questionnaire that included the Alcohol Use Disorders Identification Test (AUDIT) and gave a blood sample. The GP recorded his assessment about the presence of an alcohol-related disorder in the patient. Screening results of 1 test center were used as a calculation sample. The results at the other site were used to cross-validate the study outcomes. The markers were combined by 2 methods. The first approach used the AUDIT (QUestionnaire VERified; QUVER), and the second was performed using the clinical judgment of the treating GP (DOctor VERified; DOVER). The formulas were calculated using linear and logistic regression models, respectively. RESULTS: A total of 2,940 patients participated in the study, of whom 2,496 completed data sets that could be used for further analysis. In the receiver-operating characteristics (ROC) curves with the reference standard of an AUDIT> or =8, the area under the curve (AUC) of 78.8% for DOVER and 80.6% (QUVER) are in a higher range than the values for gamma-%CDT (75.4%) or gamma-GT (66.3%) and %CDT (74.3%) and suggest a clear superiority of the proposed marker combinations. Regarding the combinations DOVER and QUVER, the cross-validation results were almost identical, with 78.4/78.8% and 80.6/79.5%, respectively. CONCLUSION: Our study is to date the largest practice-based trial that examines the value of the markers CDT and gamma-GT and their combinations for the screening of at-risk drinking in general practice under routine conditions. Our ROC analysis clearly demonstrated that the combination of the markers gamma-GT and %CDT under routine conditions with a behaviorally oriented reference standard leads to an improvement of diagnostic performance, more so than the use of single markers.

Adult↗

PubMed1991

Black-pigmenting gram-negative bacteria in periodontal disease. I. Topographic distribution in the human dentition.

The purpose of this study was to determine the distribution of black-pigmenting Gram-negative bacteria in the dentition of periodontitis patients and to examine differences in the microbial composition of samples taken from a series of adjacent sites. Separate subgingival samples were taken from the mesial, buccal, distal and oral aspects of every tooth in 10 subjects. Thus, a total of 927 sites, 84 to 102 per patient, were scored clinically and sampled microbiologically. P. intermedia and P. melaninogenica were found in all subjects. P. gingivalis was found in 7. The organisms tended to be distributed unevenly, giving the impression of clusters of positive samples in certain areas of the dentition. 77% of all samples positive for P. gingivalis were also P. intermedia-positive. Premolars had lower frequencies and mean proportions of P. gingivalis than incisors and molars. In the premolar and molar region, frequencies and mean proportions of P. gingivalis increased with more posterior location. While frequencies indicated a similar topographic distribution of P. intermedia the mean proportions of this organism were more consistent at different locations. Based on a logistic regression model, it was estimated that the probability of detecting P. gingivalis was 34 times higher in any site which had at least 1 P. gingivalis-positive neighboring site. For P. intermedia any site with at least 1 P. intermedia-positive neighboring site had a chance 2.4 times higher of harboring the organism as well. The highest chance of detecting P. gingivalis and P. intermedia existed in deep, oral pockets of molars, which bled upon sampling.

Adult↗

PubMed2002

Risk indicators for periodontal disease in a remote Canadian community--a dental practice-based study.

OBJECTIVES: The purpose of this cross-sectional study was to identify risk markers and risk indicators for periodontal attachment loss in a remote Canadian community. Of special interest was the association between smoking and periodontal disease experience. METHODS: Data were collected from a convenience sample of 187 adult patients attending a dental office in a rural community located in Northern Ontario. Information was obtained via a questionnaire and a periodontal examination. The questionnaire included the use of dental services, self-care behaviors, general health status, smoking, and personal characteristics. Periodontal health was assessed using the mean periodontal attachment loss (MPAL), measured at two sites on all remaining teeth and the proportions of sites examined with loss of 2 mm or more and 5 mm or more. Plaque scores and measures of the number of missing teeth also were obtained. The relationships between mean periodontal attachment loss, the proportion of sites with 5 mm or more of loss and independent variables such as age, sex, current smoking status, mean tooth plaque scores, flossing frequency, and regularity of preventive dental visits were examined in bivariate and multivariate analyses. RESULTS: The data revealed a mean periodontal attachment loss of 3.9 mm (SD=1.5). The mean proportion of sites examined with loss of 2 mm or more was 0.89 and the mean proportion with loss of 5 mm or more was 0.35. In linear regression analysis, plaque scores, the number of missing teeth, age, current smoking status, regularity of dental visits, and flossing frequency had statistically significant independent effects and explained 60.0 percent of the variance in mean periodontal attachment loss. Just over 30 percent of subjects had severe periodontal disease, defined as 50 percent or more of sites examined with loss of 5 mm or more. In logistic regression analysis, missing teeth, dental visiting, smoking status, age, and flossing frequency had significant independent effects. The strongest association observed was with smoking, which had an odds ratio of 6.3. The logistic regression model correctly predicted 64.3 percent of cases with severe disease. CONCLUSIONS: The data indicate that the periodontal health of these patients is poor. Risk indicators or markers of poor periodontal health in the population studied included missing teeth, plaque scores, age, current smoking status, regularity of dental visits, and flossing frequency. This supports previous findings that behavioral factors play an important role in periodontal disease.

Adult↗

PubMedDate not supplied

A longitudinal study of the association between tooth loss and age-related hearing loss.

The purpose of this study was to investigate cross-sectional and longitudinal associations between hearing acuity and tooth loss in 1156 US veterans taking part in the Veterans Affairs' Normative Aging (NAS) and Dental Longitudinal (DLS) Studies in the Boston, MA, area. The mean age was 48 years (SD = 8.9), 5.3% were edentulous, and 15.4% had < 17 teeth at baseline. Hearing acuity was determined by puretone, air- and bone-conduction audiometry, and speech discrimination tests at triennial examinations over a 20-year follow-up period. Hearing decline was defined as a change from baseline in the average puretone air-conduction thresholds of > or = 20 dB at 0.25, 0.5, 1, 2, 3, 4, 6, and 8 kHz. The explanatory variables of interest were change since baseline in dentate status (cut points at < 1, < 17, and < 20 teeth), and in the number of teeth lost (linear). Linear and logistic regression models--which controlled for baseline audiological status, age, air-bone gap, and otoscopic examination at current visit--showed that subjects who went from having > or = 17 to < 17 teeth had 1.64 times (95% CI, 1.24-2.17) as high odds of having hearing decline as those with no change in their dentate status. For every tooth lost since baseline, there was a 1.04 times as high odds (95% CI, 1.02-1.06) for hearing decline, when additional baseline and time-varying covariates were taken into account in the model.

Adult↗

PubMed2004

Prediction of visual field progression in glaucoma.

PURPOSE: To determine the probability of future glaucomatous visual field (VF) progression with clinical and perimetric data. METHODS: One hundred sixty-one eyes of patients (161) enrolled in the Advanced Glaucoma Intervention Study (AGIS) with >or=8 years of follow-up and a baseline VF score <or=16 were selected. VF progression at 8 years was determined with point-wise linear regression (PLR) analysis, using a two-omitting algorithm. The course of VF series over the first 4 years of follow-up was quantified by an index, the sum of slopes, which is the sum of all slopes of VF thresholds with P < 0.05 when PLR was performed on the 4-year data. The following parameters were included in a logistic regression model to predict 8-year outcomes from the first 4 years of follow-up: intervention sequence, age, AGIS VF score, mean IOP, IOP fluctuation, and sum of slopes. RESULTS: Sixty-four (40%) eyes progressed after 8 years as determined by PLR analysis. Two parameters were predictive of subsequent VF progression, as identified at 8 years (predictive power: 76%): more negative sum of slopes (i.e., faster or more extensive deterioration; P < 0.001) and older age at 4 years (P = 0.049). When sum of slopes alone was used to predict outcomes at 8 years, the predictive power was the same. CONCLUSIONS: The VF sum of slopes can be used to estimate the probability of subsequent VF worsening with reasonable, clinically useful accuracy. This probability may be combined with other clinical information for more effective clinical predictions and treatment decisions.

Aged↗

PubMed2001

Clinical utility of monitoring tacrolimus blood concentrations in liver transplant patients.

The relationship between the dose of tacrolimus, trough tacrolimus blood concentration, and selected clinical endpoints (acute rejection, nephrotoxicity, and other toxicities) were examined in a prospective, multicenter clinical trial to validate the use of an enzyme-linked immunosorbent assay (ELISA) for monitoring whole-blood concentrations of tacrolimus in liver transplant patients. A total of 111 subjects from six transplant centers were evaluated over 12 weeks posttransplantation. In addition to trough tacrolimus blood concentrations, hematocrit, ALT, AST, GGTP, alkaline phosphatase, total bilirubin, serum creatinine, BUN, serum potassium, serum magnesium, blood glucose, and serum albumin were also measured. The relationship between trough tacrolimus blood concentrations and clinical endpoints was analyzed using both a logistic regression model and a Cox proportional hazard model. By logistic regression analysis, a statistically significant (p = 0.0465) relationship between increasing trough tacrolimus blood concentrations and decreasing risk of acute rejection was demonstrated over a 7-day time window. Nephrotoxicity and other toxicities also demonstrated statistically significant relationships with trough tacrolimus blood concentrations. The results of the Cox analysis were consistent with the logistic regression analysis. Using receiver operator characteristic curves, trough tacrolimus concentrations as measured by the ELISA method were able to differentiate the occurrence of nephrotoxicity and toxicity from nonevents. To minimize nephrotoxicity of tacrolimus, it is necessary to maintain trough blood concentrations below 15 ng/ml. This study demonstrates that the ELISA method used to measure tacrolimus blood concentrations in this study provides information of predictive value for managing the risk of nephrotoxicity, other toxicity, and rejection in liver transplant patients.

Administration, Oral↗

PubMed2002

Stature at time of diagnosis of type 1 diabetes mellitus.

OBJECTIVE: To assess the stature of children with type 1 diabetes mellitus at diagnosis. METHODS: We collected data from 451 records of children who were examined in a pediatric diabetes clinic and used data from the Third National Health and Nutrition Examination Survey for 10 522 children as control group. Analytical techniques included linear and logistic regression modeling. A semiquantitative meta-analysis evaluated 38 earlier publications that contain information on height at the onset of diabetes. RESULTS: Children <1 year of age were shorter than their peers by 1 standard deviation, whereas those from 3 years to near puberty were taller by approximately 0.3 standard deviation. Adjusting for parental height caused this difference to disappear for the older children but not for the infants. The meta-analysis results paralleled these observations. CONCLUSIONS: Taller children generally seem to experience increased risk for development of diabetes mellitus type 1, except perhaps during infancy or early adolescence. This observation may have implications regarding pathogenesis of this disorder.

Adolescent↗

PubMed2000

Cigarette consumption in rural China: survey results from 3 provinces.

OBJECTIVES: This study assessed cigarette consumption and its main determinants in rural China. METHODS: A logistic regression model was used to analyze status of smoking, daily amount of smoking, and expense of cigarettes in rural China. RESULTS: Approximately 57.1% of the males and 3.1% of the females were current smokers. The daily amount of smoking among smokers was 15.23 cigarettes, and their annual expenses were 227 yuan. CONCLUSIONS: People in rural China consume fewer cigarettes and are less likely to smoke than those in urban areas. Education and occupation are 2 major factors that determine the likelihood of smoking in rural China.

Adolescent↗

PubMed2001

Keeping the unemployed healthy: the effect of means-tested and entitlement benefits in Britain, Germany, and the United States.

OBJECTIVES: Although considerable evidence about the health effects of unemployment exists, little is known about the possible protective effects of various social interventions. This study examined the role that means-tested and entitlement programs could have in ameliorating the health impact of unemployment in Britain, Germany, and the United States. METHODS: Logistic regression models were used to analyze panel data from Britain (1991-1993), Germany (1991-1993), and the United States (1985-1987) available in the Household Panel Comparability Project database. The analysis included 8,726 respondents from Britain, 11,086 from Germany, and 11,668 from the United States. The health-dependent variable used was a single measure of perceived health status. RESULTS: Evidence was found of differences in perceived health status between groups of unemployed people characterized by the types of benefits they receive. When socioeconomic characteristics and previous health and employment status are controlled for, means-tested benefits do not seem sufficient to reduce the impact of unemployment on health. CONCLUSIONS: Monitoring the possible health effects of changes in public assistance benefits should be given priority in the research and political agenda.

Attitude to Health↗

PubMedDate not supplied

Depression, functional status, treatment for psychiatric problems, and the health-related practices of elderly HMO members.

PURPOSE: To study relationships between depression, functional limitations, psychiatric treatment, and the health-related practices of elderly individuals. DESIGN: Cross-sectional, observational study based on survey data (response rate = 90%) analyzed using multiple linear and logistic regression models. SETTING: Kaiser Permanente Northwest, a large nonprofit HMO. SUBJECTS: Medicare members (4615) aged 65-103 years who responded to a health status survey. MEASURES: Depression, health and functional status, frequency of alcohol consumption, smoking status, advance medical directive completion, influenza or pneumonia vaccinations, mammograms, recent psychiatric treatment, and attempts to lose weight or increase exercise. RESULTS: Self-reported depression was related to a greater risk of smoking (odds ratio [OR] = 1.54). Health-related functional limitations were related to fewer attempts to change health behaviors and less preventive service use (significant ORs ranged from 0.84 to 0.94). Minority group membership and Supplemental Security Income were negatively associated with better health practices and with completing advance medical directives (ORs 0.41 and 0.79, respectively). Falls in the prior year, more prescription medications, and psychiatric treatment were positively associated with better health practices (significant ORs ranged from 1.12 to 1.88). CONCLUSIONS: Depression and smoking are associated among elderly individuals, as are psychiatric treatment and attempts to lose weight. Those with functional limitations, minority status, or Supplemental Security Income use fewer preventive services; the latter two groups are less likely to complete advance medical directives. Older adults with these characteristics might need assistance in improving health-related practices.

Adaptation, Psychological↗

PubMed1999

Method of physician remuneration and rates of antibiotic prescription.

BACKGROUND: Rates of antibiotic prescription in Canada far exceed generally accepted rates of bacterial infection, which led the authors to postulate that rates of antibiotic prescription depend to some extent on factors unrelated to medical indication. The associations between antibiotic prescription rates and physician characteristics, in particular, method of remuneration and patient volume, were explored. METHODS: The authors evaluated all 153,047 antibiotic prescriptions generated by 476 Newfoundland general practitioners and paid for by the Newfoundland Drug Plan over the 1-year period ending Aug. 31 1996, and calculated rates of antibiotic prescription. Linear and logistic regression models controlling for several physician characteristics, specifically age, place of education (Canada or elsewhere), location of practice (urban or rural) and proportion of elderly patients seen, were used to analyse rates of antibiotic prescription. RESULTS: Fee-for-service payment (rather than salary) and greater volume of patients were strongly associated with higher antibiotic prescription rates. Fee-for-service physicians were much more likely than their salaried counterparts to prescribe at rates above the median value of 1.51 antibiotic prescriptions per unique patient per year. The association between rate of antibiotic prescription and patient volume (as measured by number of unique patients prescribed to) was evident for all physicians. However, the association was much stronger for fee-for-service physicians. Physicians with higher patient volumes prescribed antibiotics at higher rates. INTERPRETATION: In this study factors other than medical indication, in particular method of physician remuneration and patient volume, played a major role in determining antibiotic prescribing practices.

Adult↗

PubMed1999

Residential magnetic field measurements in France: comparison of indoor and outdoor measurements.

Residential magnetic field (MF) measurements were performed for the first time in a representative sample of French dwellings. Exposure levels were assessed by two methods: indoor and outdoor measurements. Linear and logistic regression models were used to determine factors associated with the time-weighted average (TWA) home MF. TWA magnetic field magnitudes were approximately log-normally distributed with geometric means under 0.010 microT for both indoor and outdoor measurements. Only 5% of the dwellings presented indoor MF levels greater than 0.120 microT (1.2 mG). Both indoor and outdoor MF variations were explained by three factors: wiring configuration, the dwelling's location (i.e., urban or rural), and housing characteristics (individual houses or apartment building). The reliability of outdoor spot measurements with 30-min bedroom recordings was assessed by an intraclass correlation coefficient. The measurements were accurate in rural areas and small towns. In urban centers, local MF variations spoil the outdoor measurement's reliability. If indoor measurements are taken as the reference method, the use of outdoor instead of indoor measurement leads to an important decrease in statistical power. Further assessment of MF near high power transmission lines is necessary to evaluate the usefulness of outdoor spot recordings near such lines. The urban MF environment also has to be explored to identify extraneous sources.

Case-Control Studies↗

PubMed2004

Thyroid cancer has increased in the adult populations of countries moderately affected by Chernobyl fallout.

BACKGROUND: The incidence of thyroid carcinoma increased among children affected by Chernobyl fallout. Less evidence exists for a corresponding effect in adolescents and adults. The Cancer Registry of the Czech Republic provides an opportunity to study various determinants of the occurrence of thyroid cancer. MATERIAL/METHODS: Anonymous population-based incidence data on thyroid carcinoma of the Czech Republic from 1976 to 1999 were obtained from the Czech Statistical Office (CSO) and the Institute of Health Information and Statistics (IHIS). This study covers 247 million person-years. Linear logistic regression models allowing for possible changes in slope (change-points) are suggested for the trends of incidence proportions. RESULTS: From 1976 to 1999 a uniform annual increase of 2.0% per year was found in the directly age-standardized thyroid cancer incidence proportion (95%-CI: 1.3-2.7, p<0.0001). From 1990 on, we observed an additional significant increase in the thyroid cancer incidence of 2.6% per year (95%-CI:1.2-4.1, p=0.0003). This effect (change-point) is essentially independent of age but dependent on gender: females 2.9% per year (95%-CI: 1.3-4.7, p=0.0006), males 1.8% per year (95%-CI: -1.0-4.7,p=0.2127). The estimated minimum latency period for the population as a whole is 4 years. CONCLUSIONS: Although the Czech Republic received only a relatively moderate amount of radioactive fallout,an unexpected uniformly accelerated increase of thyroid cancer in all age categories is seen from 1990 onwards. Therefore one should look carefully at collective dose and at the group of persons low in individual organ dose but high in number.

Adolescent↗

PubMed2006

Healthy living among seniors.

OBJECTIVES: This article investigates good health among Canadian seniors in relation to health behaviours and psychosocial factors. DATA SOURCES: Data are from the 2003 Canadian Community Health Survey and the 1994/95 through 2002/03 National Population Health Survey, household components. ANALYTICAL TECHNIQUES: Multiple logistic regression modeling was used to study associations between being in good health and behavioural risk and psychosocial factors in 2003. Proportional hazards modelling and logistic regression were used to examine health-related characteristics and psychosocial factors in relation to maintaining and recovering health. MAIN RESULTS: Seniors who exercised frequently, had a body mass index in the normal range, were high consumers of fruit and vegetables and moderate consumers of alcohol were more likely to be in good health. Low levels of stress and feeling connected to the community were also associated with good health. Healthy behaviours were related to maintaining good health over time, as well as increased likelihood of recovery. These findings persisted when controlling for socio-demographic factors and chronic conditions.

Activities of Daily Living↗

PubMed2006

Prevalence and correlates of cardiovascular risk factors in South Asians: population-based data from two California surveys.

OBJECTIVE: Few population-based studies report cardiovascular disease (CVD) risk factor prevalence for South Asians in the United States. We examined CVD risk for South Asians in California. DESIGN/SETTING/PARTICIPANTS: We used data from two population-based surveys with South Asian participants in California, the California Health Interview Survey (CHIS) and the Cardiovascular Health among Asian Indian (CHAI) survey. The CHIS 2001 was conducted in English; 769 South Asians aged 25-83 years participated as one of many ethnic groups. The CHAI survey was population-based but focused on ethnicity-specific characteristics in 304 South Asians aged 25-80 years in English and Punjabi in 2001-2002. MAIN OUTCOME MEASURES: A CVD risk score included smoking, hypertension, hypercholesterolemia, diabetes, myocardial infarction, and angina. Separate logistic regression models examined the association of sociodemographics, lifestyle, medical risk, acculturation, and "any CVD risk." RESULTS: In CHAI, hypertension (20%), hypercholesterolemia (24%), and diabetes (10%) were high; smoking was low (12%). In CHIS, prevalence of these conditions was lower, except smoking (21%). Approximately 35% of participants in each survey had any CVD risk. Male sex, age, higher body mass index, education less than a bachelor's degree, and alcohol use were associated with CVD risk in both studies. The CHAI subjects interviewed in English had higher odds of any CVD risk than those interviewed in Punjabi (odds ratio 10.3, 95% confidence interval 2.9-36.7). CONCLUSIONS: Data from multiple sources add crucial information about heterogeneity of risk within ethnic populations. South Asians in the CHIS had higher rates of smoking, but lower CVD risk scores than participants in the CHAI study. In CHAI, English language use was associated with increased CVD risk score. Additional research should examine if acculturation increases CVD risk.

Adult↗

PubMed1994

Epidemiological study of metritis in Michigan dairy cattle.

A prospective study using the Michigan National Animal Health Monitoring System was conducted to determine factors that affect the incidence of metritis in Michigan dairy herds. Data on herd management, disease, and environmental risk factors were collected from a stratified random sample of 97 herds with 7,835 cows for 12 months. Linear and logistic regression models were developed to assess the association between metritis and factors at the herd and cow level. Significant factors included retained placenta, dystocia, routine post partum examinations, herd size, and parity. Implications on the interpretation and use of results from herd- and cow-based analyses are discussed.

Animals↗

PubMed1987

Logistic regression for dependent binary observations.

The likelihood of a set of binary dependent outcomes, with or without explanatory variables, is expressed as a product of conditional probabilities each of which is assumed to be logistic. The models are called regressive logistic models. They provide a simple but relatively unknown parametrization of the multivariate distribution. They have the theoretical and practical advantage that they can be analyzed and fitted as in logistic regression for independent outcomes, and with the same computer programs. The paper is largely expository and is intended to motivate the development and usage of the regressive logistic models. The discussion includes serially dependent outcomes, equally predictive outcomes, more specialized patterns of dependence, multidimensional tables, and three examples.

Models, Theoretical↗

PubMed2002

Some relationships between spirochaete infections and digital dermatitis in four UK dairy herds.

Digital dermatitis, presenting as a focal necrotic dermatitis on the skin of cows' feet adjacent to the interdigital space, has been associated with dermal infection by spirochaetes. Lesions cause severe, transient lameness. An enzyme-linked immunoassay (ELISA) was used to measure IgG(2) antibody titres against three different spirochaetes: USA bovine Treponema isolates 1-9185MED and 2-1498, and a UK strain of Borrelia burgdorferi B31. Logistic models were used to describe lesion prevalence in terms of the antibody titres, herd and milking status, year, lactation number, and yield. The antibody titres and milking status (P<0.001) dominated the logistic fits, with the other variables adding little. Generalised linear models were used to describe the antibody titres in terms of the presence or absence of lesions, herd, year, lactation number, and yield. The presence or absence of lesions had the most significant effect for all three antibodies (P<0.001). Neither the herd effects nor the effects due to lactation number or yield showed consistent patterns.

Animal Husbandry↗