Thesis (M.Pharm. (Pharmacy Practice))---North-West University, Potchefstroom Campus, 2008.

The Sami people are the Natives of northern Scandinavia. The knowledge of the health and living conditions of the Swedish Sami is extremely limited which is in contrast to the large amount of detailed information on health and socioeconomic issues that is available for other circumpolar Natives. The encounter with the western society and the acculturation process has for many native populations had serious health consequences, causing a dramatic increase of lifestyle related diseases such as cancer, diabetes, stroke, obesity and hypertension as well as a dramatic increase of suicide and drug abuse. The overall objective of this thesis was to investigate the health conditions of the Sami population of Sweden using causes of death and incidences of cancer and cardiovascular diseases (CVD) as health indicators, and to evaluate their possible association with acculturative factors such as assimilation, integration, separation and marginalization. A Sami population was identified containing a total of 41 721 individuals. Specific cohorts were selected from this population for the different studies. A four times as large demographically matched non-Sami control population was used for comparisons. A study of causes of death, 1961-2000, showed small differences in overall mortality and life expectancy between the Sami and the non-Sami. However, Sami men showed significantly lower mortality risks for cancers but higher for external cause of injury and Sami women higher risks for diseases of the circulatory system (CVD) and of the respiratory system. An increased risk of dying from subarachnoid haemorrhage (SAH) was observed among both Sami men and women. The increased risk of dying from accidents among male reindeer herders is suggested to be caused by the increased socioeconomic pressure and the extensive use of terrain vehicles. It is concluded that commercial reindeer management is one of the most dangerous occupations in Sweden. In a study of the cancer risk among the reindeer herding Sami between 1961-1997, an overall lower risk to develop cancers, particularly prostate and malignant lymphoma was observed among the reindeer herding Sami. The risk for stomach cancer was significantly higher in relation to their non-Sami neighbours. The Sami and the non-Sami had similar risk factor-patterns for CVD. The main differences were related to working conditions and lifestyle factors of the reindeer herding Sami - the women showed a more unfavourable risk factor pattern than the men. Higher incidences of stroke were observed among Sami men and women compared to their non-Sami neighbours while the mortality rates of stroke were similar. The mortality ratio of AMI was increased for Sami women in spite of similar incidence ratios. A higher risk of SAH was observed among all groups of Sami. According to traditional socioeconomic risk factors, the differences in the levels of income and education observed between the Sami and the non-Sami, were poorely associated with the disparities of CVD. As has been shown, only minor differences in the health indicators were found between the Sami and their non-Sami neighbours. This is in clear contrast to several other native populations for which the health situation is largely unfavourable in comparison with that of the general population. The observed differences between the Sami and the non-Sami probably reflect differences in lifestyle, psychosocial and genetic factors. The relation between these factors and the acculturation process is dicussed, and it is suggested that separation or segregation of the reindeer herding Sami and the assimilation of the other Sami have influenced the health condition of the Sami, but with the largest impact probably prior to 1961 and the earliest start of follow-up for the studies in this thesis. Thus, the similarities in health between the Sami and the non-Sami 1961-2002, are probably a result of centuries of close interaction that has caused similarities in culture, attitudes and lifestyle, as well as equal accessibility to the health care services and the social security systems.

Background: Although it is well established that chronic somatic diseases are significantly associated with a wide range of psychopathology, it remains unclear to what extent subjects with chronic somatic diseases are at increased risk of experiencing mental disorders. The present epidemiological study investigates age- and sex-adjusted 12-month prevalence rates of mental disorders in patients with cancer, and musculoskeletal, cardiovascular and respiratory tract diseases, based on comprehensive physicians’ diagnoses and compared with physically healthy probands. Methods: Prevalence rates were calculated from two large epidemiological surveys. These studies investigated inpatients and patients from the general population with cancer (n = 174) and musculoskeletal (n = 1,416), cardiovascular (n = 915) and respiratory tract diseases (n = 453) as well as healthy controls (n = 1,083). The prevalence rates were based on the Munich Composite International Diagnostic Interview, a standardized interview for the assessment of mental disorders. Results: Prevalence rates were very similar for inpatients (43.7%) and patients from the general population (42.2%). The adjusted odds ratios (OR) of patients with chronic somatic diseases were significantly elevated for mental disorders in comparison with healthy probands (OR: 2.2). Mood, anxiety and somatoform disorders were most frequent. The prevalence rates did not differ significantly between the somatic index diseases. The number of somatic diseases per patient had a higher association with mental disorders. Conclusions: There is a strong relationship between chronic somatic diseases and mental disorders. A future task is to improve the care of mental disorders in patients with chronic physical illness, specifically with multimorbid conditions.

Hintergrund: Ein signifikanter Anteil der Patienten mit einer chronischen körperlichen Erkrankung weist eine komorbide psychische Störung auf. Ob und in welchem Ausmaß sich die Prävalenzraten psychischer Störungen bei Patienten mit einer chronischen Erkrankung von denen der Allgemeinbevölkerung unterscheiden, ist bislang noch kaum untersucht. Fragestellung: Die vorliegende epidemiologische Studie untersucht geschlechts- und altersadjustierte 4-Wochen, 12-Monats- und Lebenszeitprävalenzen psychischer Störungen bei Rehabilitationspatienten mit muskuloskelettalen und kardiovaskulären Erkrankungen im Vergleich zu Prävalenzraten der Allgemeinbevölkerung. Methode: Die Daten der drei Stichproben (N = 4192) basieren jeweils auf einem zweistufigen, epidemiologischen Untersuchungsansatz mit einer schriftlichen Befragung der Patienten bzw. Probanden zu ihrem psychischen Befinden (GHQ-12; M-CIDI-S) und einem anschließenden Interview (M-CIDI) bei einem randomisiert ausgewählten Teil der Gesamtstichprobe. Ergebnisse: Mit adjustierten Lebenszeitprävalenzen von 59.3 % (OR: 1.6) und 56.2 % (OR: 1.4) weisen die Patienten mit einer muskuloskelettalen und kardiovaskulären Erkrankung im Vergleich zur Allgemeinbevölkerung (47.9 %) eine deutlich erhöhte Prävalenz psychischer Störungen auf. Am häufigsten sind affektive Störungen (22.5 % bis 34.9%) und Angststörungen (18.4 % bis 33.8 %). Schlussfolgerung: Der im Vergleich zur Allgemeinbevölkerung deutliche Zusammenhang zwischen chronischen körperlichen Erkrankungen und psychischen Störungen verdeutlicht die Bedeutsamkeit einer verstärkten Diagnostik und Behandlung komorbider psychischer Störungen bei chronisch erkrankten Patienten. / Background: A significant part of patients with chronic diseases have comorbid mental disorders. However, by now it is nearly unexplored if and to what extend the prevalence rates of mental disorders in patients with chronic diseases differ from the rates of the general population. Objective: The present epidemiologic study investigates sex- and age-adjusted 4-week, 12-months, and lifetime prevalence rates of mental disorders in inpatients with musculoskeletal and cardiovascular diseases compared to prevalence rates of the general population. Methods: In each sample (N = 4192), the data based on a two-stage epidemiologic design. The first stage entailed the use of a screening questionnaire for mental disorders (GHQ-12; M-CIDI-S). The second stage consisted of an interview (M-CIDI) of a randomised part of the sample. Results: The adjusted lifetime prevalence in both clinical samples (musculoskeletal: 59.3 %, OR 1.6; cardiovaskular: 56.2 %, OR 1.4) is high compared to the rate of the general population (47.9 %). Affective disorders (22.5 % to 34.9 %) and anxiety disorders (18.4% to 33.8 %) are the most common disorders. Conclusions: Compared to the general population there is a clear correlation between chronic diseases and mental disorders, that shows the importance of an improved diagnostic and treatment of patients suffering from comorbid mental disorders.

published_or_final_version / Public Health / Master / Master of Public Health

Thesis (M.Pharm. (Pharmacy Practice))---North-West University, Potchefstroom Campus, 2008.

Η τεχνητή νοημοσύνη στη βιοπληροφορική θεωρείται ένα πολύ σημαντικό βήμα αναφορικά με την κατηγοριοποίηση των ασθενειών, ακόμα και τη θεραπεία αυτών. Μέσω των νευρωνικών δικτύων τεχνητής νοημοσύνης μπορούμε να επεξεργαστούμε ιατρική πληροφορία και να κατηγοριοποιήσουμε μοτίβα καίριας σημασίας όσον αφορά την ιατρική διάγνωση. Βέβαια, καθώς στη λήψη αποφάσεων πάντα εισχωρεί ο παράγοντας της αβεβαιότητας, μία από τις πιο κατάλληλες προσεγγίσεις, η οποία προσομοιώνει τον τρόπο που κάθε άνθρωπος λαμβάνει αποφάσεις, είναι η ασαφής λογική. Συνδιάζοντας την ασαφή λογική με τη γνώση ειδικών μπορούμε να μοντελοποιήσουμε σύνθετα φαινόμενα και να αποφανθούμε για τη φύση αυτών. Σε αυτή τη διπλωματική εργασία υλοποιείται ένα ασαφές έξυπνο σύστημα που έχει ως σκοπό να μοντελοποιήσει πέντα καρδιολογικής φύσεως ασθένειες, χρησιμοποιώντας υλικό το οποίο προέρχεται από τη γνώση ειδικών στον τομέα της καρδιολογίας: στεφανιαία νόσος, υπέρταση, κολπική μαρμαρυγή, καρδιακή ανεπάρκεια, διαβήτης. Επιπλέον, το σύστημα, σε συνεργασία με το αρμόδιο ιατρικό προσωπικό, παραμετροποιήθηκε και στη συνέχεια έγινε προσπάθεια βελτιστοποίησής του μέσω της ενσωμάτωσης νευρωνικών δικτύων. Η αποδοτικότητά του αξιολογήθηκε ευνοϊκά μέσα από μία ομάδα ιατρών, δίνοντας ελπίδες για μία νέα εποχή στον τρόπο διεξαγωγής ιατρικής διάγνωσης. Το συγκεκριμένο σύστημα θα αποτελέσει τμήμα του Cardiosmart365, ενός ολοκληρωμένου συστήματος για τη δια βίου παρακολούθηση ασθενών με καρδιολογικά προβλήματα, την έγκαιρη διάγνωση και τη βέλτιστη διαχείριση περιπτώσεων εκτάκτου ανάγκης. Σε αυτό το έξυπνο ασαφές σύστημα προσαρτάται η γνώση που προκύπτει μέσα από τα νευρωνικά δίκτυα, με την οποία και επιτυγχάνεται αυτόματα η βελτιστοποίησή του. / Arti cial intelligence (AI) in bioinformatics is considered to be a great step towards disease classi cation, or even disease treatment. AI gives the opportunity through arti cial neural networks (ANNs) to process medical information and classify pat- terns, something of great importance, as far as medical diagnosis is conserned. How- ever, since there is always the factor of uncertainty in decision making, fuzzy logic is considered to be one of the most suitable approximations, since it deals with reason- ing that is approximate rather than xed and exact, thus closer to human reasoning. Therefore, based on human expert knowledge they are capable of modeling complex phenomena. In this diploma thesis, we implement a fuzzy expert system, consisting of ve subsystems, concerning ve cariological diseases, incorporating expert knowledge on this particular eld: coronary artery disease, hypertension, atrial brillation, heart failure, and diabetes. Moreover, the parameters were con gured, in cooperation with experts on the eld, and optimization e orts were made through the integration of neural networks. Evaluated by a group of doctors, the e ciency was rated as satisfactory, giving hope for a new era in the way medical diagnosis is conducted. This system will be a part of Cardiosmart365, an integrated system for lifelong cardiologic patient monitoring, early detection of emergency, and optimal process management of the emergency incident. In the fuzzy expert system implemented, knowledge through neural networks is incorporated, thus achieving automatic opti- mization.

The increased prevalence of obesity amongst adolescents is considered a worldwide epidemic. Within the black population of South Africa, obesity is significantly more prevalent amongst black girls than black boys. The high prevalence of obesity amongst children can be attributed to a combination of various lifestyle factors, namely a decrease in physical activity, an increase in television viewing, Westernization and increased food supply. The decrease in physical activity amongst adolescents over the last few decades has led to an increase in the number adolescents diagnosed with type 2 diabetes mellitus. Research has indicated that insulin sensitivity improves with regular physical endurance activity, irrespective of change in bodyweight. Regular physical exercise also lowers the risk of type 2 diabetes mellitus, and prevents the development of coronary heart diseases, hypertension and obesity. The primary goals of this study were two-fold: Firstly, to determine the relationship between BMI, percentage body fat and insulin sensitivity amongst black adolescents, and, secondly, to determine whether there exists a positive correlation between current cardiovascular fitness (V02-maximum),together with everyday physical activity status, and insulin sensitivity amongst black adolescents. One hundred and twenty-four (124) black boys and 148 black girls between the ages of 14 and 17 participated in the study. The BOD-POD was used to calculate percentage body fat, and blood analysis for fasting glucose and insulin were completed. Insulin sensitivity (QUIKI-index) and resistance (HOMA) were also calculated, and habitual physical activity was measured using the "Previous Day Physical Activity Recall" (pDPAR) questionnaire. Physical development was determined with the Tanner questionnaire, cardiovascular fitness (VO2-maximum) was determined using the "Bleep" test and anthropometry (mass, length, skin folds, waist and hip circumference) was measured to determine body composition. The results of this study found a statistically significant negative correlation between skin fold thickness, percentage body fat, BMI and insulin sensitivity in girls. A significant negative correlation between percentage body fat and V02-maximum was found in boys, while their self-reported activity (PDPAR) did not correlate with percentage body fat. Current cardiovascular fitness and habitual physical activity status (PDPAR) showed no significant relationship with insulin sensitivity. Amongst the girls there was however a tendency towards a positive correlation between insulin sensitivity and V02-maximum. / Thesis (M.Sc. (Human Movement Science))--North-West University, Potchefstroom Campus, 2006.

Cardiovascular diseases (CVDs) are the leading cause of death and disability around the world. The purpose of this thesis is to investigate the impact of socio-environmental determinants of CVDs at the neighbourhood scale in order to inform actionable interventions, which may lead to large-scale reductions in preventable CVDs. Drawing on 2411 surveys carried out in Toronto, Canada, this thesis employs multilevel models to estimate the magnitude of socio-environmental influences on the risk of CVD while adjusting for individual-level risk factors. To advance current research methodology, strategies and innovations were developed to 1) improve the characterization of neighbourhoods by empirically testing a full range of socio-environmental influences; 2) account for non-residential exposures by including a combined analysis of work and home contexts; 3) account for variations in the duration of exposure through the use of time-weighted models; 4) deal with problem of spatial data aggregation by developing and testing a novel method of neighbourhood zone design, and 5) account for the spatial scales of different socio-environmental determinants by modeling at multiple scales. The thesis demonstrated that land use decisions are inextricably public health decisions. It found that living in neighbourhoods with inadequate access to food stores and areas for physical activity, burdened by violent crimes and fast food restaurants, and over-dependent on automobiles (leading to air pollution), with a high level of noise may significantly increase the risk of CVDs, over and above individual-level risks. The thesis also found that working in neighbourhoods that are socio-economically disadvantaged or have high-traffic may significantly increase CVD risk. The thesis developed and demonstrated novel methods to reduce the measurement error of neighbourhood exposures through 1) the use of “amoeba buffers” to improve neighbourhood zone design to better reflect participants’ local neighbourhoods and 2) the use of duration of exposure weights to adjust for individual differences in the time spent across different contexts. Finally, it found that the significance of socio-environmental factors depends on the scale of data aggregation; thus, investigation of multiple scales may be required to identify the relevant scale that matches the specific contextual factor in future research.

Cardiovascular diseases (CVDs) are the leading cause of death and disability around the world. The purpose of this thesis is to investigate the impact of socio-environmental determinants of CVDs at the neighbourhood scale in order to inform actionable interventions, which may lead to large-scale reductions in preventable CVDs. Drawing on 2411 surveys carried out in Toronto, Canada, this thesis employs multilevel models to estimate the magnitude of socio-environmental influences on the risk of CVD while adjusting for individual-level risk factors. To advance current research methodology, strategies and innovations were developed to 1) improve the characterization of neighbourhoods by empirically testing a full range of socio-environmental influences; 2) account for non-residential exposures by including a combined analysis of work and home contexts; 3) account for variations in the duration of exposure through the use of time-weighted models; 4) deal with problem of spatial data aggregation by developing and testing a novel method of neighbourhood zone design, and 5) account for the spatial scales of different socio-environmental determinants by modeling at multiple scales. The thesis demonstrated that land use decisions are inextricably public health decisions. It found that living in neighbourhoods with inadequate access to food stores and areas for physical activity, burdened by violent crimes and fast food restaurants, and over-dependent on automobiles (leading to air pollution), with a high level of noise may significantly increase the risk of CVDs, over and above individual-level risks. The thesis also found that working in neighbourhoods that are socio-economically disadvantaged or have high-traffic may significantly increase CVD risk. The thesis developed and demonstrated novel methods to reduce the measurement error of neighbourhood exposures through 1) the use of “amoeba buffers” to improve neighbourhood zone design to better reflect participants’ local neighbourhoods and 2) the use of duration of exposure weights to adjust for individual differences in the time spent across different contexts. Finally, it found that the significance of socio-environmental factors depends on the scale of data aggregation; thus, investigation of multiple scales may be required to identify the relevant scale that matches the specific contextual factor in future research.