PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Regression Analysis”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 1,027 records · Page 57Linked to original sources
PubMedDate not supplied

Multiple spatial/behavioral correlates for cells in the rat postsubiculum: multiple regression analysis and comparison to other hippocampal areas.

Head direction cells in the rat postsubiculum fire in relation to the momentary directional heading of the animal, with each cell firing only when the animal faces in one particular direction. To understand how this signal might be generated, one useful step is to discover what other cell types, in addition to the head direction cells, may exist in the postsubiculum, since these cells might be involved in helping to generate the direction-specific activity. Here postsubicular cells were recorded as animals navigated in a cylindrical recording chamber. It was found that, in addition to head direction cells, the postsubiculum contains cells that show several other types of spatial/behavioral correlates, including angular velocity of the head, running speed, and location. Ten percent of the cells were classified as angular velocity cells, and they resembled vestibular afferent fibers, with antagonistic responses to clockwise versus counterclockwise turns. In addition, numerous other cell types were observed. These latter cells were harder to classify, but all showed a significant correlation with one or more of the above variables. These findings suggest that the head direction cell signal may be at least partly based on the angular velocity, running speed, and locational signals observed here.

Animals↗
PubMed1999

Multiple logistic regression analysis of plasma paraquat concentrations as a predictor of outcome in 375 cases of paraquat poisoning.

Successful prediction of who may survive paraquat poisoning can prevent inappropriately aggressive treatment in those who have little hope of survival and those only minimally poisoned. We examined case records of patients admitted to one poisoning treatment unit over the last 5 years, and the English and French language literature on paraquat poisoning. Data were recorded from all patients where outcome and timed plasma paraquat concentrations were present. Of 375 patients (113 M, 62 F, 200 unknown), mean age 38.3 years (range 1-87 years), 49 had evidence of renal toxicity, and 41 received haemodialysis or charcoal haemoperfusion; 61 developed pulmonary sequelae; and 44 had lesions in the upper gastrointestinal tract. Median time from ingestion to death in the 241 deaths reported was 270 h (range 3-720 h). We plotted log(plasma paraquat concentration) against log(h since ingestion). The predicted probability of survival for any specified time and concentration was exp(logit)/[1 + exp(logit)], where logit = 0.58-2.33 x log(plasma paraquat)-1.15 x log(h since ingestion). This equation may be helpful in predicting who will survive after ingestion of paraquat up to at least 200 h after ingestion, and can now be used as a research tool for studies on efficacy of treatment of paraquat poisoning.

Adolescent↗
PubMed2006

Lung cancer mortality and carbon black exposure: Cox regression analysis of a cohort from a German carbon black production plant.

OBJECTIVE: We undertook a lung cancer mortality analysis of 1528 German carbon black workers, followed between the years of 1976-1998, who produced furnace black, lamp black, and gas black. METHODS: We used Cox modeling across age with time-dependent covariates, ie, cumulative and mean carbon black exposure, duration of work in departments, adjusting for calendar time, a smoking indicator, and age at hire. Exposures were lagged up to 20 years. Analyses were performed with the full cohort and after restriction to an inception cohort. RESULTS: A total of 50 lung cancer deaths occurred. No positive association was found with carbon black exposure indices. Some models indicated an increasing risk across duration of work in the lamp black producing department. CONCLUSIONS: Our results do not suggest that carbon black exposure is a human lung carcinogen. The lamp black results, if no artifact, may point at historical exposures to gaseous polycyclic aromatic hydrocarbons.

Age Factors↗
PubMed2006

Secretion of keratinolytic enzymes and keratinolysis by Scopulariopsis brevicaulis and Trichophyton mentagrophytes: regression analysis.

A survey on keratinophilic fungi from poultry-farm soils at Namakkal and from feather dumping soils at Chennai, India, revealed the existence of 34 species of fungi. Most of the fungi exhibited variable efficiency in producing extracellular keratinase when grown in plates with chicken feathers as the sole carbon and nitrogen source. The fungi Aspergillus flavus, Aspergillus niger, Aspergillus versicolor, Chrysosporium state of Arthroderma tuberculatum, Paecilomyces carneus, Scopulariopsis brevicaulis, Trichoderma viride, and Trichophyton mentagrophytes were efficient candidates to degrade the feathers. However, when cultivating the strains in submerged conditions in a medium containing chicken feathers as the sole nutrients source, Aspergillus glaucus, Chrysosporium keratinophilum, Curvularia lunata, Fusarium solani, and Penicillium citrinum also proved to be potent. Among all species, S. brevicaulis and Trichophyton mentagrophytes produced higher amounts of keratinase in both methods. Conditions for keratinase production were optimized by statistical design and surface plots. The highest keratinase activity was estimated by S. brevicaulis (3.2 KU/mL) and Trichophyton mentagrophytes (2.7 KU/mL) in the culture medium with chicken feathers and shows (79% and 72.2% of degrading ability, respectively).

Animals↗
PubMed2000

Factors associated with increased risk of exacerbation and hospital admission in a cohort of ambulatory COPD patients: a multiple logistic regression analysis. The EOLO Study Group.

BACKGROUND AND OBJECTIVE: The aim of this study was to develop and validate two models to estimate the probabilities of frequent exacerbations (more than 1 per year) and admissions for chronic obstructive pulmonary disease (COPD) that can be used in a primary care setting. METHODS: Information was obtained in a cross-sectional observational study on ambulatory COPD patients performed in 201 general practices located throughout Spain. The model for admissions included 713 cases, 499 for the developmental sample and 214 in the validation sample; the model for frequent exacerbations included 896 patients, 627 in the developmental sample and 269 in the validation model. Candidate variables to be included in both models were: age, sex, body mass index (BMI), FEV(1) as percent predicted [FEV(1 )(% pred.)], active smoking, chronic mucus hypersecretion (CMH) and significant comorbidity. RESULTS: The admission model contained 2 readily obtainable variables: comorbidity (OR = 1.97; CI 95% = 1. 24-3.14) and FEV(1)(% pred.) (OR = 0.72; 0.58-0.88, for every 10 units), and well calibrated in developmental and validation samples (goodness-of-fit tests: p = 0.989 and p = 0.720, respectively). The model for frequent exacerbations included 3 variables: age (OR = 1. 21; 1.01-1.44; for every 10 years of increasing age), FEV(1 )(% pred. ) (OR = 0.82; 0.70-0.96, for every 10 units) and CMH (OR = 1.54; 1. 11-2.14) and also well calibrated (p = 0.411 and p = 0.340 in the developmental and validation samples, respectively). CONCLUSIONS: Our results suggest that FEV(1) impairment explains part of the risk of frequent exacerbations and hospital admissions. Furthermore, CMH and increasing age are significantly associated with the risk of frequent exacerbations, but severity of exacerbations provoking hospital admissions is associated with the presence of significant comorbidity. These important and easily measurable variables contain valuable information for optimal management of ambulatory patients with COPD.

Age Factors↗
PubMed1993

Compliance in hemodialysis patients: a multivariate regression analysis.

Successful treatment of patients with end-stage renal failure requires, in addition to dialysis, strict control of dietary, fluid and medication intake. In the present study we measured, in 50 chronic hemodialysis patients, serum potassium (K), serum phosphate (PO4) and interdialytic weight gain as indices of diet, medication and fluid compliance, respectively. Dietary compliance did not correlate with fluid or medication compliance, whereas fluid intake and medication compliance were related (p = 0.01). Age, time on dialysis, place of birth and whether the patient came accompanied or not to the dialysis unit were the main variables affecting serum K levels. Sex, ethnic origin and education significantly affected serum PO4. Sex, place of birth, marital status, number of children and years of education affected fluid intake. The compliance of the hemodialysis patient with different aspects of his regimen is thus multifactorial. Attempts to improve compliance and thus reduce morbidity and mortality should be aimed at identifying the population with low compliance and exposing them to educational programs.

Adult↗
PubMed2005

Volume-based referral for cardiovascular procedures in the United States: a cross-sectional regression analysis.

BACKGROUND: We sought to estimate the numbers of patients affected and deaths avoided by adopting the Leapfrog Group's recommended hospital procedure volume minimums for coronary artery bypass graft (CABG) surgery and percutaneous coronary intervention (PCI). In addition to hospital risk-adjusted mortality standards, the Leapfrog Group recommends annual hospital procedure minimums of 450 for CABG and 400 for PCI to reduce procedure-associated mortality. METHODS: We conducted a retrospective analysis of a national hospital discharge database to evaluate in-hospital mortality among patients who underwent PCI (n = 2,500,796) or CABG (n = 1,496,937) between 1998 and 2001. We calculated the number of patients treated at low volume hospitals and simulated the number of deaths potentially averted by moving all patients to high volume hospitals under best-case conditions (i.e., assuming the full volume-associated reduction in mortality and the capacity to move all patients to high volume hospitals with no related harms). RESULTS: Multivariate adjusted odds of in-hospital mortality were higher for patients treated in low volume hospitals compared with high volume hospitals for CABG (OR 1.16, 95% CI 1.10-1.24) and PCI (OR 1.12, 95% CI 1.05-1.20). A policy of hospital volume minimums would have required moving 143,687 patients for CABG and 87,661 patients for PCI from low volume to high volume hospitals annually and prevented an estimated 619 CABG deaths and 109 PCI deaths. Thus, preventing a single death would have required moving 232 CABG patients or 805 PCI patients from low volume to high volume hospitals. CONCLUSION: Recommended hospital CABG and PCI volume minimums would prevent 728 deaths annually in the United States, fewer than previously estimated. It is unclear whether a policy requiring the movement of large numbers of patients to avoid relatively few deaths is feasible or effective.

Aged↗
PubMed1991

Therapeutic results and prognostic predictors of childhood acute lymphoblastic leukemia: Cox regression analysis.

Determining the current status of therapeutic results of acute lymphoblastic leukemia (ALL), and identifying the important clinical predictors of survival and relapse are essential for establishing therapeutic strategies. Sixty-two children with ALL who were admitted to Chonnam University Hospital from January 1983 to June 1991 were studied. With a mean follow-up period of 53.7 months, the overall 5-year survival rate (5YSR) was 46.1%. The overall rate of 5-year event-free survival (EFS) was 25.4% and significantly differed between risk groups: 48.7% for standard, 16.3% for high, and 12.5% for very high (p < .05). Overall 4-year survival after initial relapse was 34.2% and there was no significant difference in survival between those who relapsed during maintenance therapy and those who relapsed after completing maintenance. The Cox proportional hazards model identified central nervous system (CNS) irradiation (P < 0.001) as having the most important influence upon EFS, followed by serum alanine aminotransferase level, platelet level, and age. On the other hand, CNS leukemia at diagnosis, followed by mediastinal mass, and hemoglobin level were found to be the most important prognostic predictors for relapse. On the basis that present results differ from those of developed countries, we suggest the necessity of a nation-wide cohort study to delineate the characteristics of Korean ALL in children, to make our own protocols, and ultimately to improve the therapeutic outcome.

Antineoplastic Combined Chemotherapy Protocols↗