Logistic Regression

The refugee and migration crisis that took place in 2015 and affected Europe but mostly Greece and the Aegean islands, with Lesvos island, in particular, bearing most of its burden, has been the key point of discussions and confrontations among the leaders of the European Union. At the same time, most of the islanders responded immediately in handling the situation on the island. This, led to the necessity for exploring the attitude of the residents of Mytilene towards these mass refugee and migration flows in Lesvos in order to exert the necessary policy to address the issue. Within this framework, the purpose of this present study is to explore the factors that determine the attitude of the local community of Lesvos island towards the refugee and migration issue separately, emphasizing on both demographic and socio-economic factors. In particular, it seeks to explore whether there is a bearing on the attitude of the local community of Lesvos, with some determining factors such as demographic (gender, age, marital status), social (level of education), political (political positioning) and economic factors (total income) in order to check the overall impact. For the statistical analysis, modern statistical techniques are applied to address this multifaceted issue such as multiple imputation by chained equations in order to create accurate, predictive and interpretative models so as to have a comprehensive interpretation of the local society’s attitude towards refugees and migrants.

Several methods which have been adopted to analyze multi-category data yields unsatisfactory results because of strict assumptions regarding normality, linearity, and homoscedasticity. As a result, Multinomial logistic regression is considered as an alternative because it does not assume normality, linearity, or homoscedasticity (Hosmer & Lemeshow, (2000)). The study attempted to use Maximum likelihood estimation and predicted probability to model Maternal Health Care Services data based on a set of explanatory variables. Also to determine the indices that affect Mortality rate. The result shows that wealth index has a significant impact on the use of public and private health delivery facilities. Educational level, antenatal care, assistance during delivery and place of residence are also important factors in assessing Maternal Health Care Services. Finally, the study revealed that educated women, who are wealthy, living in urban areas and who received antenatal care services and assistance during delivery are more likely to utilize Maternal Health Care Services (MHCS)

The mean value of average overall running speed (AORS) in Zagazig city main
streets (ZCMS) is about 10 kph. This means that traffic congestion is common
phenomenon all over ZCMS. This leads to more trips delays, traffic accidents, fuel
consumption, air pollution, noise, etc. Many reasons cause traffic congestion
specially the huge number of running vehicles on ZCMS all day time comparing to
their characteristics. This study aims to decrease the running vehicles volume on
ZCMS to its minimum and improve level of service. A comprehensive experimental
program was designed and implemented starting with reviewing past studies then
designing questionnaires to collect data required to define and improve the current
situation. Two questionnaires were designed to define ZCMS current situation and to
forecast the proposed situation in the case of adding new mode facilities. Analyzing
collected data, utility functions for current situation scenario (Scenario 0), adding
public buses system to current modes scenario (Scenario 1), and adding luxury public
buses system to current modes scenario (Scenario 2) are determined. Based on the
calculated utility functions, volume of different commonly types of modes in Zagazig
enough to generated trips implementation are determined. As well as corresponding
real number and types of modes used in implementing Zagazig generated daily trips
(ZGDT). Analyzing study results, it is found that no significant difference is noticed
between real volumes of modes required to implementing ZGDT and the identical
determined using utility functions of Scenario 0. Appling polices of Scenario 1
reducing the volumes of modes required to implementing ZGDT to 44.90% of the original required volumes. Applying Scenario 2 reaches volume reduction to 56.97%.
It’s anticipated that AORS in ZCMS will be increased by 42% applying polices of
Scenario 1 and 64.5% when applying polices of scenario 2.

The aim of this study is to determine the effects of demographic variables such as age, gender, education, working status, working years in sector and working years in accommodation business on life satisfaction. Survey technique was used in the study. The data were obtained by using Diener et al. (1985) Life Satisfaction Scale and personal information form. The research was carried out on 598 employees working in the accommodation business in Manavgat, an important tourism destination of Antalya. Research data were analyzed with SPSS 23.0 statistical package program. Firstly, the reliability of the
scales (Cronbach Alpha) was tested. Afterwards, factor analysis (principal component analysis) was applied to the life satisfaction scale and a single dimension was obtained. In this study, logistic regression analysis was used to determine the effects of independent variables consisting of categorical variables on the binary dependent variable. As a result of the logistic regression analysis, it was determined
that the full-time or seasonal working status, which is one of the demographic variables affecting the life satisfaction of the employees, had a statistically significant effect and it was revealed that the full-time
work would reduce life satisfaction according to the seasonal work. The effects of other demographic variables were not statistically significant.

Medical therapy with dopaminergic drugs is the preferred initial treatment for symptomatic prolactin (PRL)-secreting adenomas; but in recent years, there has been a renewed interest in surgery. The aim of this study is to report a large series of patients operated for prolactinoma in the last 10 yr. A total of 120 consecutive patients (93 female, 27 male) underwent surgery from January 1990 to December 1999. Their mean age at surgery was 29.7 +/- 0.9 yr. Fifty-nine patients (49.2%) had a microadenoma, and the remaining 61 (50.8%) had a macroadenoma, of which 24 (20%) were intrasellar and 37 (30.8%) were extrasellar adenoma. Magnetic resonance imaging signs of invasion of the cavernous sinus were detected in 18 patients (15.0%). Thirty-one patients (25.8%) had never been treated before, whereas the remaining 89 (74.2%) had received dopaminergic drugs. After surgery, normalization of PRL levels occurred in 77 patients (64.2%). Logistic regression analysis showed that the only predictive factor of unsuccessful surgery was a high preoperative PRL level. Recurrence of hyperprolactinemia occurred in 13 of the 77 cured patients (16.9%) during a mean follow-up of 50.2 +/- 3.0 months; the 5-yr disease-free survival was 75.9%. Extrasellar extension of the tumor and presence of a postoperative PRL response to TRH were associated with a lower risk of relapse. In summary, surgery normalized PRL levels and relieved symptoms of hyperprolactinemia in most patients. Recurrence of hyperprolactinemia occurred within 4 yr after surgery. Transsphenoidal surgery can be offered as a definitive therapy, especially to patients with intrasellar tumors.

Medical therapy with dopaminergic drugs is the preferred initial treatment for symptomatic prolactin (PRL)-secreting adenomas; but in recent years, there has been a renewed interest in surgery. The aim of this study is to report a large series of patients operated for prolactinoma in the last 10 yr. A total of 120 consecutive patients (93 female, 27 male) underwent surgery from January 1990 to December 1999. Their mean age at surgery was 29.7 +/- 0.9 yr. Fifty-nine patients (49.2%) had a microadenoma, and the remaining 61 (50.8%) had a macroadenoma, of which 24 (20%) were intrasellar and 37 (30.8%) were extrasellar adenoma. Magnetic resonance imaging signs of invasion of the cavernous sinus were detected in 18 patients (15.0%). Thirty-one patients (25.8%) had never been treated before, whereas the remaining 89 (74.2%) had received dopaminergic drugs. After surgery, normalization of PRL levels occurred in 77 patients (64.2%). Logistic regression analysis showed that the only predictive factor of unsuccessful surgery was a high preoperative PRL level. Recurrence of hyperprolactinemia occurred in 13 of the 77 cured patients (16.9%) during a mean follow-up of 50.2 +/- 3.0 months; the 5-yr disease-free survival was 75.9%. Extrasellar extension of the tumor and presence of a postoperative PRL response to TRH were associated with a lower risk of relapse. In summary, surgery normalized PRL levels and relieved symptoms of hyperprolactinemia in most patients. Recurrence of hyperprolactinemia occurred within 4 yr after surgery. Transsphenoidal surgery can be offered as a definitive therapy, especially to patients with intrasellar tumors.

Quantitative methods to assess the creditworthiness of the loan applicants are vital for the profitability and the transparency of the lending business. With the total loan volumes typical for traditional financial institutions, even the slightest improvement in credit scoring models can translate into substantial additional profit. Yet for the regulatory reasons and due to the potential model risk, banks tend to be reluctant to replace the logistic regression as an industrial standard with the new algorithms. This does not stop researchers from examining such new approaches, though. This thesis discusses the potential of the support vector machines, to become an alternative to logistic regression in credit scoring. Using the real-life credit data set obtained from the P2P lending platform Bondora, the scoring models were built to compare the discrimination power of support vector machines against the traditional approach. The results of the comparison were ambiguous. The linear support vector machines performed worse than logistic regression and their training consumed much more time. On the other hand, support vector machines with non-linear kernel performed better than logistic regression and the difference was statistically significant at 95 % level. Despite this success, several factors prevent SVM from the widespread applications in credit scoring, higher training times and lower robustness of the method being two of the major drawbacks. Considering the alternative algorithms which became available in the last 10 years, support vector machines cannot be recommended as a standalone method for credit risk models.

Several recent reports of high local recurrence and lymph node metastasis in T1 carcinoma of the rectum prompted us to study the risk factors for lymph node metastasis in these lesions. We reviewed the clinical records of 7,543 patients who underwent operative treatment for carcinoma of the colon and rectum from 1979 to 1995. Only patients with sessile T1 lesions who underwent colorectal resection were included in the study, yielding an analysis cohort of 353 patients. The following carcinoma-related variables were assessed: size, mucinous subtype, carcinomatous component, grade, site in colon and rectum, lymphovascular invasion, and depth of submucosal invasion. For the depth, the submucosa was divided into upper third (sm1), middle third (sm2), and lower third (sm3). Chi-squared tests and logistic regression were used to evaluate the variables as potential risk factors for lymph node metastasis. The incidence of T1 lesions was 8.6 percent. In the analysis cohort, the lymph node metastasis rate was 13 percent. Significant predictors of lymph node metastasis both univariately and multivariately were sm3 (P = 0.001), lymphovascular invasion (P = 0.005), and lesions in the lower third of the rectum (P = 0.007). Poorly differentiated carcinoma was significant univariately (P = 0.001) but not in the multivariate model. No other parameter was associated with a significant risk. T1 colorectal carcinomas with lymphovascular invasion, sm3 depth of invasion, and location in the lower third of the rectum have a high risk of lymph node metastasis. These lesions should have an oncologic resection. In a case of the lesion in the lower third of the rectum, local excision plus adjuvant chemoradiation may be an alternative.

To investigate the multiple effects of socioeconomic factors on cognitive impairment in older persons. Subjects were a nationally representative sample (n = 4,155) aged >or=65 years of the Korean Longitudinal Study of Aging. Cognitive status was assessed by the Mini-Mental State Examination. Education, income, wealth and occupation were measured, with low levels on each factor combined to produce an aggregate risk score. Multiple logistic regression was used to analyze the combined effects of socioeconomic risks on cognitive impairment. A socioeconomic risk gradient was evident, with the combined effect being stronger than any one of the risk factors acting alone. Compared with those with no risks, the odds ratios were 2.4 (for 2 socioeconomic risks), 3.4 (3 risks) and 7.7 (4 risks) for men, and 2.8 (2 risks), 3.5 (3 risks) and 5.4 (4 risks) for women. For individual socioeconomic risks, income and occupation were significant predictors of cognitive impairment in men, whereas in women, all 4 factors were independently associated. Multiple socioeconomic risks have a combined effect on cognitive impairment in older adults.

Demonstrations of memory changes in those at risk for Alzheimer's disease by the presence of the APOE e4 allele have been inconsistent to date. The present study went beyond traditional analyses of central tendency (i.e., group differences on mean test scores) and also conducted distribution analyses to search for subtle cognitive differences in subgroups of normal-functioning elderly persons with the APOE e4 genotype. The results of the study revealed that (a) the e4 and non-e4 groups failed to differ in terms of their mean scores on tests of memory and verbal skills; and (b) relative to the non-e4 group, the e4 subjects had significantly greater heterogeneity of variance on the memory measures but not on fundamental verbal skills. Logistic regression analyses indicated that the discrepancy in scores on the memory measures was a significant predictor of genotype group membership (82% correct classification rate). Implications of these findings for the detection of a preclinical phase of AD are discussed.

Many analytical approaches to single-case data assume either linear effects (regression-based methods) or instant effects (mean-based methods). Neither assumption is realistic; therefore, these approaches' assumptions are often violated. In this article, we propose modeling curvilinear effects to appropriately parametrize the characteristics of singe-case data. Specifically, we introduce the generalized logistic function as adequate function for this situation. The merits of the proposed procedure are demonstrated using data previously used in single case research that represent typical single case data. We provide the function with auxiliary graphical options to demonstrate the model parameters. The function is freely available in the R package "userfriendlyscience." The proposed procedure is a new way to analyze single case data, which may provide applied single case researchers with a new tool to better understand their data and avoid applying methods with violated assumptions.