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At least 721 records · Page 40Linked to original sources
PubMed2001

[Logistic regression analysis of wedge-shaped defects in the middle-aged and elderly].

OBJECTIVE: To investigate and identify the possible clinical risk factors associated with the formation of wedge-shaped defects. METHODS: Four hundred and ninety-three subjects were examined. The possible risk factors associated with wedge-shaped defects were identified by logistic regression analysis. RESULTS: The prevalence of wedge-shaped defects was observed 90.5% in this population. The prevalence and severity of wedge-shaped defects were found to be increasing with age. The correlation between age, sex, preferred side for tooth chewing, brushing twice a day, malocclusion, the formation and severity of wedge-shaped defects were noted. CONCLUSION: Occlusal factors and tooth brushing have found related to the formation of wedge-shaped defects.

Age Factors↗
PubMedDate not supplied

Predictive value of different prognostic factors in breast cancer recurrences: multivariate analysis using a logistic regression model.

BACKGROUND: The aim of this study was to compare the sensitivity of different pre-operative parameters in patients with breast cancer (BC) recurrence using univariate and multivariate analysis. MATERIALS AND METHODS: We retrospectively analyzed a series of 387 women (median age 60 years, range 35-83 years) who underwent curative surgery for pT1-2 BC. The patients were divided into two groups: Group 1: 325 (84.0%) patients with no evidence of disease during a median follow-up of 53 months (range 25-149 months) and Group 2: 62 (16.0%) patients who developed local or distant recurrences. RESULTS: Univariate analysis showed significant (p<0.01) differences between the two Groups in age, size and grading of the tumor and hormone receptor rate. MIB1 proliferation rate, serum markers CEA and CA 15-3, and lymph node status were not useful in predicting relapse. Multivariate analysis using a logistic regression model showed that only age, size of the tumor and hormone receptor rate independently correlate with the onset of recurrences. CONCLUSION: There is no clear correlation between BC recurrence and the majority of the prognostic factors available. Multivariate analysis of several pre-operative parameters may help to correctly select the high risk population.

Adult↗
PubMedDate not supplied

A multiple logistic regression analysis of risk factors in different subtypes of gastric ulcer.

BACKGROUND/AIMS: To elucidate the relationship among disparate ulcer risk factors in 3 subtypes of gastric ulcer. METHODOLOGY: One hundred and fifty-nine age-matched controls, 30 patients with ulcer craters in the gastric body (GU-I), 55 with coexistent gastroduodenal ulcer (GU-II), and 69 with ulcer craters in the prepyloric region (GU-III) were examined for potential risk factors. These included cigarette smoking, nonsteroidal anti-inflammatory drug use, Helicobacter pylori infection, gender and ABO blood group. Using multiple logistic regression analysis, Odds ratios of relevant risk factors associated with different subtypes of gastric ulcer were reported. RESULTS: Among all gastric ulcer subsets, cigarette smoking, nonsteroidal anti-inflammatory drugs use and H. pylori infection were independent ulcer risk factors. For GU-I, smoking (OR: 3.98; 95% CI: 1.44-11.0) and nonsteroidal anti-inflammatory drugs use (OR: 4.33; 95% CI: 1.10-17.1) raised the likelihood of ulceration. For GU-II and GU-III, smoking, nonsteroidal anti-inflammatory drug use and H. pylori infection were identified as risk factors. H. pylori infection carried the strongest association with gastroduodenal ulcer (OR: 9.29; 95% CI: 3.11-27.7) in GU-II, and nonsteroidal anti-inflammatory drug use generated the highest possibility of GU-III (OR: 11.3; 95% CI: 3.49-36.5). Nonsteroidal anti-inflammatory drug use also markedly raised the likelihood of multiple gastric ulcers (OR: 17.0; 95% CI: 4.21-68.9). CONCLUSIONS: Stratification analysis showed differential influences of risk factors on separate subtypes of gastric ulcer. These data support the hypothesis that peptic ulcer disease is heterogeneous in etiology and pathogenesis.

Aged↗
PubMedDate not supplied

Combination of HCGbeta, CA 19-9 and CEA with logistic regression improves accuracy in gastrointestinal malignancies.

BACKGROUND: Earlier studies suggest that the free beta-subunit of human chorionic gonadotropin (hCGbeta) may be a useful tumour marker for gastrointestinal cancers. Our aim was to investigate hCGbeta in serum in gastrointestinal diseases in comparison with CA 19-9 and carcinoembryonic antigen (CEA). PATIENTS AND METHODS: The serum concentrations of hCGbeta, CA 19-9 and CEA were measured from 142 patients with malignant and 178 with benign gastrointestinal diseases. The diagnostic accuracies of the markers were compared and a diagnostic algorithm was established with logistic regression (LR) analysis. RESULTS: The hCGbeta serum level was elevated most frequently in bile duct (56%), pancreatic (45%) and gastric cancer (41%). In benign diseases, hCGbeta concentration was elevated in 10% of the patients. In an LR model each marker provided independent diagnostic information and the probability of cancer was calculated. It was applied as a diagnostic algorithm providing better accuracy than the markers alone. In receiver operating characteristic (ROC) curve analysis the area under the curve (AUC) value of the algorithm was significantly higher than the AUC values of CA 19-9, CEA, or hCGbeta (p=0.009-0.049). CONCLUSION: Serum hCGbeta, CA 19-9 and CEA provide additive diagnostic information in gastrointestinal malignancies and the use of an algorithm established by LR analysis improves diagnostic accuracy.

Adult↗
PubMed2003

A randomized double blind, placebo controlled trial of topical Tripterygium wilfordii in rheumatoid arthritis: reanalysis using logistic regression analysis.

OBJECTIVE: To assess the efficacy of topical Tripterygium wilfordii (TW), a Chinese herbal therapy, in rheumatoid arthritis (RA). METHODS: A 6 week randomized double blind placebo controlled study of 61 patients with RA meeting American College of Rheumatology (ACR) criteria was conducted in China. The primary outcome was a modified ACR-20 response rate, analyzed by logistic regression analysis. RESULTS: The modified ACR-20 response rate differed significantly (topical TW 58% vs placebo 20%; p = 0.002). There was an 8.1-fold (95% CI 1.9-35.4) increase in the modified ACR-20 response for the TW compared to the placebo group, adjusted for age and erythrocyte sedimentation rate. CONCLUSION: Topical TW appears efficacious for the treatment of RA, but larger studies are needed.

Adult↗
PubMed2003

Predicting sediment toxicity using logistic regression: a concentration-addition approach.

The question posed in this article is how useful the chemical concentration measurements for predicting the outcome of sediment toxicity tests are. Using matched data on sediment toxicity and sediment chemical concentrations from a number of studies, we investigated several approaches for predicting toxicity based on multiple logistic regression with concentration-addition models. Three models were found to meet criteria for acceptability. The first model uses individual chemicals selected using stepwise selection. The second uses derived variables to reflect combined metal contamination, polycyclic aromatic hydrocarbon (PAH) contamination, and the interaction between metals and PAHs. The third and final model is a separate species model with derived variables. Overall, these models suggest that toxicity may be correctly predicted approximately 77% of the time, although prediction is better for samples identified as nontoxic than for those known to be toxic.

Animals↗
PubMed2003

Using logistic regression to detect item-level non-response bias in surveys.

This article describes a procedure for evaluating item-level non-response bias in questionnaire items. Specifically, logistic regression is used to determine whether non-responses are random or systematic in nature for one question from the National Educational Longitudinal Study of 1994 concerning drug use behaviors. It turns out that, indeed, non-responses are systematic with males and lower achieving students being more likely to contribute to non-response along with two-way interactions between ethnicity and SES and ethnicity and geographic region. In addition, the magnitude of the potential bias is estimated, which demonstrates that the parameter estimates obtained by assuming that the data are missing at random may be extremely biased, given this frame of reference. Finally, several steps are suggested for evaluating the threat of non-response bias in survey research.

Adolescent↗
PubMed2003

[Logistic regression model analysis on Bolton ratio of orthodontic extraction model].

OBJECTIVE: The purpose of this study was to evaluate the role of Angle's class, overall ratio and anterior ratio in the creation of tooth size discrepancies, and to determine whether any tooth extraction combinations create more severe discrepancies. METHODS: 166 dental casts of orthodontic patients were selected randomly. These models were classified according to angle's criterion. Mesio-distal dimensions of mandibular and maxillary teeth were measured before treatment, and subjected to Bolton's analysis. Hypothetical tooth extraction by the following combinations: all the first premolars, all the second premolars, upper first and lower second premolars, and upper second and lower first premolars, was performed on each patient. The measurement results were again subjected to Bolton's analysis to see whether any tooth-size discrepancy had been created. The results were evaluated statistically by means of Logistic regression model. RESULTS: Overall ratio, anterior ratio and extraction models affected mesio-distal tooth size ratio of both maxillary and mandibular teeth in the final stage of orthodontic treatment, Whereas, the results showed no significant difference among these groups of malocclusion. CONCLUSION: The results suggested that dentists should always keep in mind that each patient should be treated individually and should be aware of that other factors also played important roles in determining what teeth, if any, should be removed and the Bolton analyses of all kinds of extraction models should be carried out, as well as the general Bolton analysis.

Adolescent↗
PubMed2003

[Analysis of the nasal complication after radiotherapy in patients with nasopharyngeal carcinoma by logistic regression].

OBJECTIVE: To study of the risk factors of the nasal complication after radiotherapy in patients with nasopharyngeal carcinoma(NPC). METHOD: Observed 131 cases nasal disease in NPC patients, analyzed the factors that might cause the complication by using Logistic regression model. RESULT: The highest incidences of complication after radiotherapy was chronic purulent sinusitis (116/131), the chosen factors in the regression formula were T staging and radiation for anterior field of the nose. The second was nasal synechia(33/131), the chosen factors were total dose of external irradiation, intracavitary irradiation and medicamentous rhinitis. The incidences of atrophic rhinitis was the lowest (9/131), the chosen factors were chemotherapy and medicamentous rhinitis. CONCLUSION: T staging of tumor and radiation for anterior field of the nose had relation with post radiotherapy sinusitis. It was easy to lead to nasal synechia when the does of external irradiation being higher or adding intracavitary irradiation or using the decongestant for long time. Chemotherapeutic drugs and decongestant may be the risk factors of atrophic rhinitis.

Adolescent↗
PubMed2003

Using rough sets, neural networks, and logistic regression to predict compliance with cholesterol guidelines goals in patients with coronary artery disease.

Coronary artery disease is a leading cause of death and disability in the United States and throughout the developed world. Results from large randomized, blinded, placebo-controlled trials have demonstrated clearly the benefit of lowering LDL cholesterol in lowering the risk for coronary artery disease. Unfortunately, despite the quantity of evidence, and the availability of medications that can efficiently lower LDL cholesterol with few side effects, not everyone who could benefit from cholesterol lowering interventions actually receives them. Despite the dissemination of national care guidelines for the evaluation and treatment of cholesterol levels (NCEP - National Cholesterol Education Program), compliance with such guidelines is suboptimal. There clearly is room for improvement in narrowing the gap between evidence based guidelines and actual clinical practice. The ability to classify those patients who are or will likely to be noncompliant on the basis of patient data routinely collected during patient care could be potentially useful by enabling the focusing of limited health care resources to those who are or will be at high risk of being under treated. In order to explore this possibility further, we attempted to create such classifiers of cholesterol guideline compliance. To do this, we obtained data from an ambulatory electronic medical record system at use at the MGH adult primary care practices for over 20 years. We obtained the data from this hierarchically-structured EMR using its own native query language, called MQL (Medical Query Language). Next, we applied to the collected data the machine learning techniques of rough set theory, neural networks (feed forward backpropagation nets), and logistic regression. We did this by using commonly available software that for the most part is freely available via the internet. We then compared the accuracy of the classifier models using the receiver operating characteristic (ROC) area and C-index summary metrics.

Cholesterol↗
PubMed2003

A validated logistic regression model to identify coronary heart disease patients within primary care databases in the United kingdom.

We established the optimal search strategy for identifying coronary heart disease (CHD) patients within the Electronic Patient Record (EPR) of 'paperless' family practices in the UK. Multiple logistic regression modelling (MLRM) and Receiver Operating Characteristic (ROC) curves were used to develop the query. The selected search strategy was validated at 2 additional paperless family practices.

Adult↗
PubMedDate not supplied

[Analysis of mortality and relative prognostic factors in general surgery: use of the multiple logistic regression model].

Surgical risk is defined as the occurrence of complications arising in the individual as a result of surgical stress. The ability to forecast these consequences is an important factor in determining decision taken by surgeon. Several attempts have been made to quantify postsurgical prospects but up till now no overall solution has been found. This paper attempts to define a multifactorial risk index for adults subjected to surgery, with respect to immediate and early per- and post-surgical complications. 1182 adult patients, 14 yrs or more, surgically treated not for urgency during 1985 in six Italian centres, were prospectively studied in order to derive a multivariate prognostic index of after surgery mortality. Stepwise logistic regression model was applied to a set of preoperative and operative factors, five of which were found significantly correlate with death: nutritional status, renal failure, reintervention, bacterial contamination during surgery, age greater than 70 years. Thus, from regression coefficients, scores were derived for modalities of significant variables, allowing to build four classes of risk patients: low (less than 1%), medium (between 1% and 10%), high (between 10% and 50%), extremely high risk (greater than 50%).

Adolescent↗
PubMed2004

[The morbidity of chronic diabetic complication with logistic regression analysis of related potential risk factors].

OBJECTIVE: To investigate the morbidity and potential risk factors of chronic diabetic complication in Zhejiang province. METHODS: In the paper the morbidity of diabetic chronic complication was illustrated, using descriptive statistics. The potential risk factors of diabetic chronic complication were studied with logistic regression modeling, using data from a large retrospective study involving 1083 patients from two hospitals in Zhejiang province. RESULTS: Principal chronic diabetic complications were found to be cardiovascular diseases, ophthalmic diseases, nephropathy, esthetic diseases, plant nerve diseases, cerebral blood vessel diseases, limbsblood vessel diseases and athletic nerve diseases. The principal potential risk factors would include the courses of diabetes and hypertension, age, age being diagnosed, blood pressure, baseline blood glucose, two hour blood glucose after dietary, HBAIC, nitroglycerine, cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol. CONCLUSION: The analytic method used in the paper was fit for the study of morbidity and potential risk factors of other chronic diseases complication and the discriminant function could be built for clinical diagnosis.

China↗
PubMed2004

[Combination of variance components estimation, regression trees and logistic regression as a concept for exploring associations between animal husbandry conditions and lesions found at slaughter].

Integrated quality control measures have been discussed in farm animal husbandry and veterinary medicine for some time in search of concepts to link information on management factors with disease data gained by veterinary meat inspection at slaughter. Better understanding of relationships between these variables hopefully will help to improve management practices as well as meat quality and safety. In order to analyse data gained on-farm and at slaugherhouses and to investigate relationships between animal husbandry conditions and lesion occurrence at slaughter a biometrical concept has been developed. This concept combines a characterization of variation structures, the generation of regression trees to explore association structures in available animal management and disease data, and logistic regression used to quantify systematic effects of farm management factors. The combination of these three steps is illustrated with an example.

Analysis of Variance↗
PubMed2004

[Logistic analysis on risk factors related to smear positive pulmonary tuberculosis].

OBJECTIVE: To explore the risk factors on relapsing tuberculosis related to smear positive pulmonary tuberculosis which had been cured for five years. METHODS: Patients with smear positive pulmonary tuberculosis registered in 1995 from ten countries in Hubei province were studied and logistic regression was used for data analysis. RESULTS: The 5-year relapse rate of smear positive pulmonary tuberculosis was 3.85 percent. Risk factors related to relapse would include being non-modeled county, negative smear after treated for three months, the class of retreatment, management of non-DOTS, method of chemotherapy and patients that did not get treated by the tuberculosis institute, with odds ratios of 0.15, 4.62, 3.68, 5.88 and 6.47, respectively. CONCLUSION: Effect standard, regulation DOTS and the centralized management measure might have had effects on decreasing the relapse rate.

Adolescent↗
PubMed2005

Clinical evaluation of the temporomandibular joint following orthognathic surgery--multiple logistic regression analysis.

This study compares temporomandibular joint dysfunction (TMD) symptoms before and after bilateral sagittal split ramus osteotomy, and identifies predictive factors for the postoperative TMD symptoms by assessing the adjusted odds ratio using multiple logistic regression analysis. A consecutive series of 37 cases treated only with bilateral sagittal split ramus osteotomy were evaluated. New postoperative TMD symptoms appeared in 9 cases, preoperative TMD symptoms disappeared in 6 cases, and TMD symptoms were unchanged in 5 cases. The median period until the interincisal opening range attained 40 mm was 5 months (range, from 2 to 15 months). Age was a positive factor in patients with postoperative TMD symptoms, with an odds ratio of 1.43 (95 percent confidence interval, from 1.05 to 1.93). In addition, the maximum value of the bilateral setback distance of more than 9 mm was a positive factor of 6.95 (95 percent confidence interval, from 1.06 to 45.42). We concluded that surgical correction in skeletal malocclusion may affect temporomandibular joint dysfunction symptoms.

Adult↗
PubMed2005

Prognosis for sudden sensorineural hearing loss: a retrospective study using logistical regression analysis.

Sudden sensorineural hearing loss (SSNHL) remains a controversial problem with respect to etiology and the factors that might predict prognosis. We used logistical regression analysis to determine which factors are most strongly related to outcome for patients with SSNHL. In so doing, we employed a retrospective chart-review study. The study group consisted of 296 patients (296 ears). The outcome of SSNHL was cured (full recovery) in 64, recovered (partial recovery) in 175, and no change in 57. We performed separate analyses on those in the no-change and partial-recovery groups and on those in the no-change and full-recovery groups. The following factors were studied as explanatory variables: age; number of days until presentation; vestibular symptom; initial mean hearing level at 0.25 kHz, 0.5 kHz, 1 kHz, 2 kHz, and 4 kHz; and treatments (steroids, satellite ganglion block). In the first analysis, for patients in the no-change and recovered groups, the factors most strongly related to outcome were the number of days until presentation and age. The second analysis, for the nochange and cured groups, revealed that the number of days until presentation, vestibular symptom, age, and initial mean hearing level were most strongly related to outcome. Our results will increase the ability to predict the outcome for SSNHL.

Adolescent↗
PubMed2006

Computation of decision levels from differentiated logistic regression probability curves.

The determination of clinical decision levels (DL) or "cut-offs" for laboratory parameters involves the analysis of sensitivity and specificity at varying levels of the predictor variable (PV). Commonly, receiver-operator characteristic (ROC) curves are used for this purpose. However, the association between a binary outcome choice and a continuous PV is often tested for statistical significance by logistic regression (LoRe), which also provides estimates of outcome probability (P) at various levels of the PV. Utilizing a graphical procedure based on the 1st [f'(P)] and 2nd [f"(P)] derivatives of the probability curve, DL were computed for simulated data sets (sims) and for actual data from a case-control study and compared with those obtained from ROC curves. Sims were constructed for 5 sets of two outcomes (n = 50, each outcome) of normally distributed data with progressive overlap and for 2 sets of fewer data (n = 15 and 9 per outcome, respectively). Additionally, data from a study of the relationship between serum Mg+2 concentration and outcomes in chronic obstructive pulmonary disease (COPD) were analyzed. DL from LoRe was taken to be the point where f"(P) = 0. For sims, the DL from LoRe correlated well with the optimum DL from ROC analysis (n = 7; r2 = 0.93; p = 0.0004). DL for Mg+2 in COPD data from LoRe was 0.83 mmol/L compared to mean of 0.82 mmol/L by ROC. These data suggest that, when the strength of association between outcomes and PV is analyzed by LoRe, DL can be determined from the probability curves. Moreover, LoRe may provide a useful method to determine DL with less ambiguity than those obtained from ROC curves, as well as provide measures of dispersion for the DL.

Decision Support Techniques↗