Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Logistics”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 991 records · Page 55Linked to original sources
PubMedDate not supplied

Evaluation of susceptibility status of Culex quinquefasciatus larvae to few organophosphorus insecticides based on logistic regression analysis.

A laboratory trial was carried out at Pune to evaluate the effectiveness of five types of larvicides viz. Malathion, Temephos, Fenthion, Dichlorvos and Fenitrothion against Culex quinquesfasciatus larvae. The expected number of mortality at various dose levels for the five types of insecticides were estimated separately using logistic regression model. Based on the fitted model, the estimated dose level corresponding to the 90 percent mortality (LC90) was obtained for each insecticide. Approximate 95 percent confidence intervals for the LC90 dose, in each case, has been provided. The analysis revealed that out of all the five types of insecticides included in the study, fenthion was the most effective. The estimated value of LC90 in this case was the lowest and is equal to 0.007 mg/L. The effectiveness of temephos, dichlorvos and fenitrothion was found to be approximately same and malathion was the least effective. The results were found to be comparable with that obtained under probit method.

Animals↗
PubMed1994

Prognostic factors in childhood asthma: a logistic regression analysis.

Thirty-two factors related to childhood asthma were studied in 200 asthmatic children. Remission of asthma was defined as a period of at least 2 years free of asthma while receiving no treatment. Univariate analysis showed significant associations between persistence of asthma and perennial symptoms with an odds ratio (OR) of 2.5 (95% confidence intervals 1.2 to 5.5); sensitization to house dust mites OR 3.5 (1.2 to 9.6); sensitization to molds, OR 7.9 (2.9 to 21.6); sensitization to pollen, OR 4.8 (1.4 to 16.3); and sensitization to milk protein, OR 5.4 (1.8 to 15.9). There was a positive association of remission of asthma with good treatment compliance, OR 12.1 (1.6 to 91.6). A stepwise logistic regression analysis selected the variables: perennial symptoms (S: 0 = no, 1 = yes), length of follow-up time (T: number of months), treatment compliance (C: 0 = poor, 1 = good), sensitization to fungi (F: 0 to 4), and sensitization to milk protein (M: 0 to 4). The analysis yielded the following formula for calculation of probability of asthma remission P(R): [formula: see text] where S indicates perennial symptoms; T, follow-up time in months; C, compliance; F, allergy to fungi; and M, allergy to milk.

Adolescent↗
PubMed1993

[An application of multiple logistic regression analysis to an outcome study on surgery for patients with femoral neck fracture].

Sixty five patients with femoral neck fracture were examined to find any risk factor for their postoperative complications. Here, postoperative complications included cardiac catastrophe, pulmonary embolism, central nervous system accident, and respiratory failure requiring mechanical ventilation during the period of one week after operation. Multiple logistic regression analysis was used to predict these factors. Explanatory variables were selected based on the clinical judgement. Those variable are age, sex, preoperative underlying cardiac disease, preoperative underlying respiratory complications, the use of cement for the procedure, and anesthetic technique. The analysis revealed that the sex was the only variable that was considered significant based on the P value less than 0.05. However, multi-colinearity between variables was suspected to exist based on the correlation matrix analysis which may indicate that the factor is not, in fact, significant. In short, further study will be required to find any significant variables or risk factors to predict the outcome of untoward events.

Aged↗
PubMed1996

Effect of alcohol intake on the efficacy of interferon therapy in patients with chronic hepatitis C as evaluated by multivariate logistic regression analysis.

The effect of alcohol intake on the efficacy of interferon (IFN) therapy was evaluated retrospectively in patients with chronic hepatitis C diagnosed by liver histology and positive serum hepatitis C virus (HCV)-RNA. Patients included 119 given IFN therapy and 11 no IFN therapy. Serum HCV-RNA was measured 6 months after discontinuation of IFN therapy in 92 treated patients, 27.2% of whom showed disappearance of serum HCV-RNA. Multivariate logistic regression analysis revealed that this disappearance was affected by alcohol intake, the presence of its history (p < 0.05) or cumulative alcohol consumption (kg) (p < 0.01), and serum HCV-RNA levels (p < 0.001). The odds ratio associated with serum HCV-RNA still positive at 6 months was 7.018 (95% confidence interval: 1.444-34.062) and 1.004 (1.001-1.007) for the presence of alcohol intake history and the cumulative alcohol consumption, respectively. Other predictor variables-such as sex and age of patients, history of blood transfusion, HCV genotype, histological findings of the liver, and types of IFN-had no influence on the efficacy of the therapy. Cumulative alcohol consumption showed a negative correlation with serum HCV-RNA levels pretreatment, when the outcome variable was divided into two categories based on serum HCV-RNA levels: 10(6) copy/ml or less and 10(7) copy/ml or more. Alcohol intake was positively correlated with histological extent of alcoholic fibrosis, but affected neither grading nor staging of chronic viral hepatitis. We conclude that alcohol intake was a risk factor on the efficacy of IFN therapy in chronic hepatitis C patients. This effect was independent of serum HCV-RNA levels and histological findings specific for viral hepatitis in the liver.

Adult↗
PubMed1997

[Logistics characteristics and surgical aspects of heart transplantation].

Orthotopic cardiac transplantation is an established treatment for terminal cardiac diseases. The organization of the operation closely depends on the successful team work between cardiologists, selecting the proper patients for this procedure, the anesthesiologists taking care of the multiorgan donor and the cardiac surgeons managing in parallel the donor and the recipient. Accurate donor evaluation and treatment are essential for a perfect graft function immediately after transplantation. Orthotopic heart transplantation can also be offered as a therapeutical option in adolescents presenting with end-stage heart failure due to complex congenital heart disease and who have sustained multiple previous operations. In this paper, some special logistic and technical particularities of cardiac transplantation are presented and discussed.

Assisted Circulation↗
PubMed1997

Logistics of performing an ophthalmic assessment in elderly inpatients.

To assess the feasibility of performing an ophthalmic assessment on elderly inpatients, we examined 48 patients over 75 years of age who were consecutively admitted to an acute elderly-care ward. Difficulties were encountered in 35 patients (73%). By employing simple methods to overcome these problems, useful information was obtained in all cases and the time taken to complete the examination ranged from six to 20 minutes (mean 7.5 minutes). Doctors looking after elderly patients should be encouraged to assess visual function and must not be deterred by anticipated logistical difficulties.

Aged↗
PubMed1997

Logistics and design issues in the use of biological samples in observational epidemiology.

Standard epidemiological study designs are well suited to answering questions involving the collection of biological samples. However, different designs are better suited--both for design and logistic reasons--to different questions. The strengths and weaknesses of each design are discussed in relation to markers of exposure, susceptibility and early outcome, and to markers used to classify cancers into biologically defined subsets.

Animals↗
PubMed1976

Use of the logistic model in retrospective studies.

A logistic regression model is used to study the association between a dichotomous exposure variable and a disease. The method takes into account factors that may confound the association and leads to a quantitative study of the influence of factors which are related to the strength of the association. Special results are given for matched pair data. A case-control study relating post-menopausal estrogen use and endometrial cancer provides illustration.

Biometry↗
PubMedDate not supplied

Analysis of image cytometry data of fine needle aspirated cells of breast cancer patients: a comparison between logistic regression and artificial neural networks.

Image flow cytometry data of aspirated tumour cells from 102 patients with breast cancer were analysed and used as prognostic markers in an attempt to predict involvement of axillary lymph nodes and histological grade using logistic regression. Prediction was 70% for both nodal status and histological analyses. The outcome of this study is compared to an earlier study using the same cytological information to obtain prediction using a neural approach. Using artificial neural networks, prediction accuracy was 87% and 82% for nodal status and histological assessment, respectively. This study also attempts to identify the impact of individual prognostic factors. The statistical approach identified S-phase fraction and DNA-ploidy as the most important prediction markers for nodal status and histological assessment analyses. A comparison was made between these two quantitative techniques.

Analysis of Variance↗
PubMed1998

[New distribution forms for pharmaceuticals--a logistic perspective].

Pharmaceuticals are an important input in health care. As a complement to other modes of treatment and as a substitute for hospitalisation, they affect the health of individuals and populations. Enormous public financial resources are spent on pharmaceuticals, and halting the growth in expenditures is a political objective. Factors with room for improvement include drug use efficiency, cost-efficient prescription, purchasing prices and distribution. High distribution costs affect prices and, thus, the assessment of product cost vs. utility. Changes in the distribution system may be important, for three reasons: First, increased capital costs call for higher efficiency. Second, increased competition requires improved logistics. And third, information technology has opened up for new supply chain solutions. Direct sales solutions are being considered, and were discussed in a Norwegian public report on the matter, but no final conclusion has been reached. This article discusses changes in the supply of pharmaceuticals and the development of the market. Alternative supply chains are outlined, including what role the postal service may play in a deregulated pharmaceutical market.

Cost-Benefit Analysis↗
PubMed1996

Maximum likelihood estimation of the kappa coefficient from bivariate logistic regression.

We propose a maximum likelihood estimator (MLE) of the kappa coefficient from a 2 x 2 table when the binary ratings depend on patient and/or clinician effects. We achieve this by expressing the logit of the probability of positive rating as a linear function of the subject-specific and the rater-specific covariates. We investigate the bias and variance of the MLE in small and moderate size samples through Monte Carlo simulation and we provide the sample size calculation to detect departure from the null hypothesis H0: kappa = kappa 0 in the direction of H1: kappa > kappa 0.

Analysis of Variance↗
PubMedDate not supplied

Logistic analysis of studies with two-stage sampling: a comparison of four approaches.

This paper discusses the analysis of two-stage studies where covariates are missing or measured with error at the first stage of sampling and are validated at the second stage in a subsample. Four recently developed approaches, the weighted pseudo-likelihood method of Flanders and Greenland (1991), the pseudo-conditional likelihood methods of Breslow and Cain (1988) and Schill et al. (1993) and the maximum likelihood estimate obtained via the EM-algorithm (Wacholder and Weinberg, 1994) are reviewed, and some connections between them are established. It is shown that, with respect to odds ratio estimation, case-control designs can be analysed as if first-stage sampling had been prospective. The procedures are numerically compared with respect to asymptotic relative efficiency in a missing value setting.

Algorithms↗
PubMed2000

Utilization of multiple imperfect assessments of the dependent variable in a logistic regression analysis.

Often, in biomedical research, there are multiple sources of imperfect information regarding a dichotomous variable of interest. For example, in a study we are conducting on the relationship between cocaine use and stroke risk, information on the cocaine use of each study patient is available from three fallible sources: patient interviews; urine toxicology testing, and medical record review. Regression analyses based on a rule for classifying patients from this information can result in biased estimation of associations and variances due to the misclassification of some subjects and to the assumption of certainty. We describe a likelihood-based method that directly incorporates multiple sources of information regarding an outcome variable into a regression analysis and takes into account the uncertainty in the classification. The method can be applied when some sources of information are missing for some subjects. We show how the availability of multiple sources can be exploited to generate estimates of the quality (for example, sensitivity and specificity) of each source and to model the degree to which missing data are informative. A fitting algorithm and issues of identifiability are discussed. We illustrate the method using data from our study.

Adult↗
PubMed1997

Logistic transmission modeling for the simulated data of GAW10 problem 2.

A recently developed nonparametric method is a generalization of the transmission disequilibrium test across all alleles of a locus. This approach has been applied to Problem 2 of GAW10 and has been extended to explore the combined contribution of neighboring loci for chromosomes 1, 5, and 8. When applied to the chromosome 5 data of the first replicate of the nuclear pedigrees from Problem 2 of GAW10, the data show that four of the 25 loci obtain a probability less than 0.05. However, when combined models composed of each potentially significant marker (p < 0.05) and its nearest neighbors are considered, the combined contributions of G14 and G15 are the most significant (p = 0.007). Consequently, the region near G14 and G15 is identified as the best candidate region in chromosome 5 for linkage to the common disease.

Case-Control Studies↗
PubMed2002

Functional data analysis with application to periodically stimulated foetal heart rate data. II: functional logistic regression.

We present a basis solution for the modelling of a binary response with a functional covariate plus any number of scalar covariates. This can be thought of as singular longitudinal data analysis as there are more measurements on the functional covariate than subjects in the study. The maximum likelihood parameter estimates are found using a basis expansion and a modified Fisher scoring algorithm. This technique has been extended to model a functional covariate with a repeated stimulus. We used periodically stimulated foetal heart rate tracings to predict the probability of a high risk birth outcome. It was found that these tracings could predict 94.1 per cent of the high risk pregnancies and without the stimulus, the heart rates were no more predictive than chance.

Adult↗