Determination of Respiratory Parameters by Means of Hurst Exponents of the Respiratory Sounds and Stochastic Processing Methods.

OBJECTIVES: System approach to the human respiratory system and input/output signals which characterize the system properties were not explored in detail in the literature. The aim of this study is to propose a combination of methods to investigate the indirect relationship between the fractal properties of Respiratory Signals (RS) and Respiratory Sound Signals (RSS) and the clinically measured respiratory parameters. METHODS: We used Hurst exponent to reveal the fractal properties of RS and RSS and to estimate the pressures in the respiratory system. The combination of well-known statistical signal processing methods and optimization were applied to the experimentally acquired 23 records. Pearson correlation coefficient and Bland-Altman analysis were the chosen validation methods. RESULTS: Considerable amounts of Hurst exponent values of RSS were found to be between 0.5 and 1, which means increasing trend or decreasing trend can be seen in RSS with fractional Gaussian process properties. Results of the pressure estimator revealed that internal pressure due to tissue viscoelasticity is higher than the pressure due to static elasticity. Feature power and skewness also provided distinctive results for all recordings. CONCLUSION: Hurst exponent values of the RSS are fruitful representation of the signals which bring the underlaying system characteristics into the surface. We illustrated that required number of sensors can be reduced in the feature calculation to ease implementation effort on the hardware of the handheld devices. SIGNIFICANCE: Bland-Altman plots were very successful to demonstrate the connection between the sets of measured respiratory parameters and calculated features.

Analysis of linear lung models based on state-space models.

BACKGROUND AND OBJECTIVES: Linear parametric respiratory system models have been used in the model-based analysis of the respiratory system. Although there are studies exploring the physiological correctness and fitting accuracy of the models, they are not analysed in terms of interaction between parameters and dynamics of the model. In this study we propose to use state-space modelling to yield the time-varying nature of the system incorporated by the parameters. METHODS: We tested controllability, observability and stability characteristics of the equation of motion, 2-comp. parallel, 2-comp. series, viscoelastic, 6-element and mead models while using the parameters given in the literature. In the sensitivity analysis we proposed to use dual Desensitized Linear Kalman Filter (DKF) and Extended Kalman Filter (EKF) method. In this method, state error covariance revealed the parameter sensitivities for each model. RESULTS: Results showed that all models, except 2-comp. parallel and mead models, are both controllable and observable models. On the other hand all models, except mead model, are stable models. Regarding to the sensitivity analysis, dual DKF - EKF method estimated states of the models successfully with a low estimation error. Sensitivity analysis results showed that airway parameters have higher effects on the state estimation than the other parameters have. CONCLUSION: We proved that state-space evaluation of the previously proposed parametric models of the respiratory system led us to quantitative and qualitative assessments of the respiratory models. Moreover parameter values found in the literature have different effects on the models.

Correlation analysis of respiratory signals by using parallel coordinate plots.

BACKGROUND AND OBJECTIVES: The understanding of the bonds and the relationships between the respiratory signals, i.e. the airflow, the mouth pressure, the relative temperature and the relative humidity during breathing may provide the improvement on the measurement methods of respiratory mechanics and sensor designs or the exploration of the several possible applications in the analysis of respiratory disorders. Therefore, the main objective of this study was to propose a new combination of methods in order to determine the relationship between respiratory signals as a multidimensional data. METHODS: In order to reveal the coupling between the processes two very different methods were used: the well-known statistical correlation analysis (i.e. Pearson's correlation and cross-correlation coefficient) and parallel coordinate plots (PCPs). Curve bundling with the number intersections for the correlation analysis, Least Mean Square Time Delay Estimator (LMS-TDE) for the point delay detection and visual metrics for the recognition of the visual structures were proposed and utilized in PCP. RESULTS: The number of intersections was increased when the correlation coefficient changed from high positive to high negative correlation between the respiratory signals, especially if whole breath was processed. LMS-TDE coefficients plotted in PCP indicated well-matched point delay results to the findings in the correlation analysis. Visual inspection of PCB by visual metrics showed range, dispersions, entropy comparisons and linear and sinusoidal-like relationships between the respiratory signals. CONCLUSION: It is demonstrated that the basic correlation analysis together with the parallel coordinate plots perceptually motivates the visual metrics in the display and thus can be considered as an aid to the user analysis by providing meaningful views of the data.

The risk of overweight and obesity in children after tonsillectomy: a cross-sectional study.

The aim of this cross-sectional study was to determine the prevalence of tonsillectomy among secondary school children and to investigate whether tonsillectomy with or without adenoidectomy is a risk factor for childhood obesity. A total of 27 secondary schools with 12,296 students between the ages 11 and 17 were screened in Denizli, Turkey. We determined 129 students who had undergone tonsillectomy; each student was matched with two healthy control subjects of the same age and sex (n = 258). A 28-item questionnaire on nutrition and physical exercise was completed by the parents. Age-adjusted body mass index and waist circumference percentiles of Turkish boys and girls were used for the assessment of overweight and obesity. The prevalence of tonsillectomy was 1.0 %. There was no significant relationship between having tonsillectomy and being overweight or obese and physical exercise and screen time (p > 0.05 for each). Logistic regression analyses suggested no significant effect of tonsillectomy on overweight or obesity of the subjects (p > 0.05). It seems that tonsillectomy had no effect on overweight and obesity among children.

Challenges in access to health services and its impact on quality of life: a randomised population-based survey within Turkish speaking immigrants in London.

BACKGROUND AND AIM: There are a significant number of Turkish speaking immigrants living in London. Their special health issues including women's health, mental health, and alcohol and smoking habits has been assessed. The aim of this study was to explore the ongoing challenges in access to health care services and its impact on Quality of Life of immigrants. MATERIAL AND METHODS: This cross-sectional population-based study was conducted between March and August 2010 with Turkish immigrants (n = 416) living in London. Of these, 308 (74%) were Turkish and 108 (26%) were Turkish Cypriots. All healthy or unhealthy adults of 17-65 years of age were enrolled. A structured questionnaire with 44 items in five subcategories and 26-items WHOQOL BREF were used. RESULTS: Mean duration of stay for Turkish Cypriots (26.9 ± 13.9 years) was significantly longer than Turkish immigrants (13.3 ± 7.5) (p < 0.001). Turkish immigrants (n = 108, 36.5%) need interpretation more often when using health services than Turkish Cypriots (n = 16, 15%) (p < 0.001). Multivariate analyses suggested significant effects of older age, non-homeownership, low socioeconomic class, poor access to health services, being ill, poor community integration and being obese on physical well-being and also significant effects of low income and poor community integration on perceived overall Quality of Life (WHOQOL) of the participants. CONCLUSIONS: The results of this study demonstrate how the health and well-being of members of the Turkish speaking community living in London are affected by social aspects of their lives. Providing culturally competent care and interpretation services and advocacy may improve the accessibility of the health care.

The well-being and treatment satisfaction of diabetic patients in primary care.

BACKGROUND: The quality of life in patients with diabetes is reduced and emotional coping with the disease has great impact on patient well-being. OBJECTIVES: The aim of this study was to assess the psychological well-being and treatment satisfaction in patients with type 2 diabetes mellitus in primary care. STUDY DESIGN AND SETTING: Patients (n = 112) with type 2 diabetes mellitus diagnosis for at least six months were enrolled. The Well-Being Questionnaire-22 and the Diabetes Treatment Satisfaction Questionnaire were used. Physical examination and laboratory investigations were performed. RESULTS: The rates of the achieved targets were 32.1% for hemoglobin A1c, 62.5% for cholesterol and 20.5% for blood pressure. The mean scores for the general well-being, depression, anxiety, positive well-being and energy were 44.40 +/- 13.23 (range = 16-62), 12.65 +/- 3.80 (range = 5-18), 10.57 +/- 4.47 (range = 1-18), 12.00 +/- 4.01 (range = 2-18), and 9.16 +/- 2.47 (range = 2-12), respectively. The mean scores for the treatment satisfaction, perception for hyperglycemia and perception for hypoglycemia were 22.37 +/- 9.53 (range = 0.00-36.00), 1.71 +/- 1.59 (range = 0-6), and 0.51 +/- 0.98 (range = 0-6), respectively. There were significant associations between the depression score and the educational status, compliance to diet and physical exercise, and diabetic complications; between the anxiety score and the educational status, glycemic control, compliance to diet and physical exercise; between the energy score and the educational status, compliance to physical exercise, and diabetic complications; between the positive well-being score and the educational status, compliance to diet and physical exercise, complications and type of treatment; between the general well-being score and the educational status, compliance for diet and physical exercise, and complications. Treatment satisfaction was significantly associated to the educational status, glycemic control and compliance to diet and physical exercise. A significant correlation was found between the treatment satisfaction and the well-being. CONCLUSIONS: Individualized care of patients with diabetes should consider improving the quality of life. Psychosocial support should be provided to the patients with type 2 diabetes and the negative effects of psychopathological conditions on the metabolic control should be lessened.

Self-perceived body weight status and weight-control behaviors of high school students in a southern city of Turkey.

Defining "healthy weight" is not easy and for an adolescent with all concerns about newly developing physiognomy it is even harder. The aim of this study was to find out the frequency of obesity and the association between the body mass index (BMI), weight-control behaviors and self-perceived body weight status in high school students of a southern city of Turkey. The students from 10 schools were randomly selected among 46,271 students of 72 high schools in Adana from 1999 to 2000. The response rate was 94.8% (2352/2480). The Turkish version of Youth Risk Behavior Survey Questionnaire (YRBSQ) was completed by the students. The students' weights and heights were measured. The mean age was 16.5 +/- 1.0 years of age (range = 14-21 years). The mean BMI was 21.0 +/- 3.1, 25.5% of students were underweight, 65.7% were normal, 6.4% were overweight and 2.3% were obese (p = 0.0001). Of all students, 24.3% defined themselves as thin, 45.3% as normal, 24.9% as overweight and 5.5% as obese (p = 0.0001). The percentage of girls defining their body weight as overweight and obese was significantly higher than the boys (p = 0.0001). Of all students, 35.5% wanted to lose weight, 22.3% wanted to gain weight, 27.8% wanted to keep their current weight. Intention (p = 0.0001) and interventions to lose weight such as going on a diet (p = 0.0001), provocative vomiting (p = 0.0001) and 24-hours starving (p = 0.0001) were significantly higher in girls than boys. Of students, 26.8% (n=620) were on a diet program either to lose or to keep their body weight. There was significant relationship between being on a diet program and intention to change body weight (p = 0.047). We concluded that adolescents living in Adana have relatively higher risk of being underweight than being obese and have unhealthy weight changing plans due to their misperception of their body images. Adolescents may be unconscious on plans and attempts to change their body weights and nutrition and we suggest that education on nutrition and health is required for adolescents.

Prevalence of migraine diagnosis using ID Migraine among university students in southern Turkey.

In this prospective study, we aimed to determine the prevalence of migraine and non-migraine headaches using a questionnaire, including ID Migraine, for university students. The study was designed cross-sectionally and a questionnaire consisting of 43 questions was applied to 1,256 students. The questionnaire consisted of questions related to demographic, social, curriculum, housing and headache characteristics of the subjects. Three-item screening questions of the ID Migraine test were included at the end of the questionnaire aimed at migraine diagnosis. The mean age of 1,256 students (529 females and 727 males) enrolled in this study was 21.9 +/- 2.1 years (17-31 years). Migraine-type headache was detected in 265 subjects (21.9%) based on the ID Migraine evaluation. Of these, 145 (54.7%) were female and 120 (45.3%) were male (female/male ratio: 1.2/1). Non-migraine-type headache was identified in 864 subjects, with 357 females and 507 males. As a conclusion, ID Migraine screening test might be practical and beneficial when a face-to-face interview is not possible or to pre-determine the subjects for a face-to-face interview for migraine diagnosis in larger populations.

The prevalence of risky behaviors related to violence in high school students in a southern city, Turkey.

Injuries are the leading cause of mortality and morbidity in adolescents and can be grouped as unintentional (such as motor vehicle crashes and fires) and intentional (violence and suicide). The aim of this study was to find the prevalence of high risk behaviors related to violence in high school students. The population comprised 2,480 randomly selected students from 10 schools among 46,271 students from 72 high schools in 1999-2000 in Adana and 2,352 (94.8%) were reached. They completed a Youth Risk Behavior Survey Questionnaire (YRBSQ). The mean age was 16.5 +/- 1 (14-21) years. 275 (11.7%) students stated that they carried a knife or a sharp weapon during the last 30 days, 151 (6.4%) carried a gun, 710 (30.2%) participated in a physical fight, 68 (2.9%) were threatened or injured by a weapon, 73 (3.1%) could not attend school because of threats from other students, 96 (4.1%) were forced into sexual intercourse. Male students were significantly more likely than female students to report all types of high risk behaviors except forced sexual intercourse. The rate of risky behaviors increased with higher grade. Violence towards and by adolescents is a severe problem. Families, teachers, and health care professionals should be aware of risk factors and be active in prevention of high risk behaviors in youth.

Respiratory parameter estimation in linear lung models.

If the respiratory system is represented as a one compartment model composed of linear electrical elements, the Minimum Variance Unbiased Estimation (MVUE) is the optimum statistical method to estimate the model parameters. Two well known linear models, RIC and Viscoelastic models were chosen and their parameters were estimated by MVUE. Synthetic data simulations showed that minimum 100 Hz sampling rate is required in order to have minimum variance. Estimation of lung inertance and viscoelastic tissue compliance parameters resulted in very large estimation variance, whereas the rest of the parameters were estimated successfully. Both parameter values and estimator variances have their own characterization in terms of patient discrimination for diagnostic purposes.

Lung model parameter estimation by unscented Kalman filter.

Dynamic nonlinear models are the best choice to analyze respiratory systems and to describe system mechanics. In this work, Unscented Kalman Filtering (UKF) was used to estimate the dynamic nonlinear model parameters of the lung model by using the measured airway flow, mask pressure and integrated lung volume. Artificially generated data and the data from Chronic Obstructive Pulmonary Diseased (COPD) patients were analyzed by the proposed model and the proposed UKF algorithm. Simulation results for both cases demonstrated that UKF is a promising estimation method for the respiratory system analysis.

Headache characteristics in senior medical students in Turkey.

Headache is one of the most common neurological complaints of the young population and it affects the quality of life due to limitation of daily activities. In this study, our main goal was to appraise the general headache characteristics in senior medical students just before graduation and to determine the impact of headache on the quality of life, as well as the general attitude of students about their headaches. The study group consisted of 141 senior students. As the first step, the question about "having headache within the past one year period" was asked. Of the 141 students, 127 students answering "yes" were invited to a face-to-face interview. Of these, 67 students (52.8%) participated in the second evaluation. The second evaluation consisted of history taking and neurological and physical examination. All subjects were classified according to the International Classification of Headache Disorders (2nd edition) criteria. Validated Turkish version of Migraine Disability Assessment questionnaire was given to the subjects to evaluate the socio-economical impact of headache. Tension-type headache, which is the most common form of primary headaches, was identified in 34 students (50.7%) out of 67 students. Migraine was detected in 31 students (46.3%). This is the first study performed on a face-to-face interview basis with medical students using the new classification criteria in Turkey. Astonishingly, most of the students (n:65) ignored their headaches and did not seek medication, despite the negative impact of headache on daily functioning and overall quality of life.

Assessing poverty and related factors in Turkey.

Poverty, a complex, multidimensional, and universal problem, has been conceptualized as income and material deprivation. In this article, we discuss poverty and related factors in Turkey. The absolute poverty line for Turkey was US$ 4 per capita per day. Turkey was ranked 92nd out of 177 countries with moderate human development in the 2006 Human Development Report. The individual food poverty rate was 1.35% and the non-food poverty rate was 25.6%. The highest poverty rate was among primary school graduates (42.5%; 38.5% for women and 46.8% for men). The rate for this group was higher in urban than in rural areas. Among poor people, 57.2% were married. The highest poverty rate was among agricultural workers (46.6%) and in Eastern and Southeastern Anatolia. Factors related to poverty were crowded households, unemployment, immigration, working for a daily wage in the agricultural and construction sector, low educational status, female sex or married status, lacking social insurance, and living in rural areas or in Eastern and Southeastern Anatolia.

Which is the best anthropometric technique to identify obesity: body mass index, waist circumference or waist-hip ratio?

This study was designed to define the most suitable anthropometric technique among body mass index (BMI), waist circumference (WC) and waist-hip ratio (WHR) as indices of obesity in adult people living in Adana, a Southern province of Turkey. A random sample design was used. A total of 900 individuals (men and non-pregnant women aged 25-65 years) were enrolled in the study. Of subjects, 50.9% were females. Anthropometric measurements were performed. Data were analysed using statistical package program. The prevalence of obesity among adults living in Adana was 20.8% 28.4% when defined using BMI, 30.5% by WC and 15.8% 42.0% by WHR. Truncal obesity and gynoid obesity showed similar prevalence with 26.6%, in the same age group. Waist circumference, BMI and WHR identified different proportions of the population, as measured for obesity prevalence. The most common methods for diagnosing overweight and obesity are based on BMI (kg/m2). However, BMI is suboptimal marker for total body fat percentage and even less suitable to assess body fat distribution. WHR is the most useful measure of obesity and the best simple anthropometric index in predicting a wide range of risk factors and related health conditions.

Avian influenza in Turkey--will it influence health in all Europe?

Avian influenza is an infection caused by avian influenza (bird flu) viruses, which occur naturally among birds. Wild birds worldwide carry the viruses in their intestines, but usually do not get sick. However, avian influenza is very contagious among birds and can cause illness and death in some domesticated birds, including chickens, ducks, and turkeys. The virus can transmit from birds to humans, causing lethal infections, but as yet the virus does not easily transmit from human to human. However, there is a substantial risk of either re-assortment of virus (combination of avian and human influenza), or adaptation of the influenza virus to humans. The present situation in Turkey emphasizes the importance of good surveillance and updated pandemic plans in all countries.

The antibiotic prescribing behaviourof physicians for acute tonsillopharyngitis in primary care.

OBJECTIVES: Acute tonsillopharyngitis is one of the most common reasons for antibiotic use although it is mostly viral. There seems to be a large variation between physicians in prescribing antibiotics. The aim of this study was to explore the antibiotic prescribing behaviour of physicians while treating cases with acute tonsillopharyngitis. PATIENTS AND METHODS: Data were collected using a questionnaire designed to investigate the effect of the antibiotics actively promoted by pharmaceutical companies, the sociodemographic details of primary care physicians, the geographic location (urban-rural) of the primary care organizations, and the effect of laboratory investigations on provider antibiotic prescribing behaviour in the treatment of acute tonsillopharyngitis. Sixty six primary care organisations (PCOs) and 316 primary care physicians working in the 66 PCOs in Adana in 2001 were involved in the study. RESULTS: Out of 66 PCOs, 55 (83%) were urban and 11 (16%) were rural. The response rate was 79%. There was significant association between antibiotic prescription for acute tonsillopharyngitis and geographic location, antibiotic promotion by pharmaceutical companies and postgraduate training for physicians (p = 0.001, p = 0.0001, p = 0.0001, respectively). There was also significant association between laboratory investigation and geographic location, postgraduate training for physicians, and period since graduation (p = 0.0001, p = 0.0001, p = 0.003, respectively). CONCLUSIONS: Antibiotics in cases with acute tonsillopharygitis are more frequently prescribed in rural areas and in PCOs where the visits and motivation from pharmaceutical companies are intensive. Physicians without postgraduate vocational training prescribe more antibiotics for cases with acute tonsillopharyngitis.

Suicidal thought and behavior in high school students in Adana, Turkey.

Fifty years ago adolescents mostly died of natural causes, whereas they now die from more preventable causes. Part of this change has been a worldwide rise in adolescent suicide rates in both developed and developing countries. Suicides are probably under reported due to cultural and religious stigma attached to self-destruction. Objectives of this study were to collect data about suicidal thoughts, plans and attempts and related sociodemographic details in high school students. The population comprised 2,480 randomly selected students among 46,271 students from 72 high schools in 1999-2000 in Adana and 2,352 (94.8%) students from 10 schools were reached and given a questionnaire modified using Youth Risk Behavior Survey Questionnaire (YRBSQ). Chi2 and Kolmogorov-Smirnov tests were used. Mean age was 16.5 +/- 1 (14-21) year, 1,187 (50.5%) students reported severe desperation, 526 students (22.4%) had suicidal thoughts, 332 (14.1%) planned committing suicide, 145 (6.2%) attempted suicide. The occurrence rate of desperation, suicidal thoughts, plans, attempts and the mean number of attempts were significantly higher in females than males. Adolescent suicide is a tragedy affecting individual, family, peers, and community. Families, teachers, and physicians should be aware of risk factors for suicide.

Predictors of smoking behavior of first year university students: questionnaire survey.

AIM: To assess the prevalence of smoking and sociodemographic factors related to smoking behavior of first year university students in Adana, Turkey. METHODS: The sample was selected from two faculties (Faculty of Engineering and Architecture and Faculty of Agriculture) using the method of simple cluster sampling, representing the university student population. The students filled out an anonymous questionnaire comprising 17 questions related to their sociodemographic characteristics and smoking behavior. The response rate was 73.5% (471 out of 640 students). RESULTS: The prevalence of daily smoking among the first year students was 21.4%, with the predominance of men (25.0%) over women (12.9%). Most students (89.1%) had positive expectations about quitting smoking in the next 5 years ("I will quit smoking", "I will decrease the number of cigarettes I smoke", and "I will continue to be a non-smoker"). The smoking behavior was significantly related to student's sex (p=0.026, Pearson's chi-square test), mother's education (p=0.029, Pearson's chi-square test), number of failed grades (p=0.011, ANOVA), student's monthly income (p<0.001, Pearson's chi-square test), and having friends who smoke (p<0.0001, Pearson's chi-square test). CONCLUSION: The main determinants of regular smoking behavior for university students in Turkey were male sex, low academic performance, having smoking friends, high level of income, and a mother with high education level. These findings call for making anti smoking policies more specific in regard to the targeted population.