<p>The Kappa coefficient is widely used in assessing categorical agreement between two raters or two methods. It can also be extended to more than two raters (methods).  When using Kappa, the shortcomings of this coefficient should be not neglected.  Bias and prevalence effects lead to paradoxes of Kappa. These problems can be avoided by using some other indexes together, but the solutions of the Kappa problems are not satisfactory. This paper gives a critical survey concerning the Kappa coefficient and gives a real life example. A useful alternative statistical approach, the Rank-invariant method is also introduced, and applied to analyze the disagreement between two raters.</p>

<p>Morbidity of asthma has increased over the world. The reasons for this increase have remained unclear. Studies in children have reported considerable East-West difference in the prevalence of atopy and respiratory allergies.</p><p>The aim of this thesis was to compare the prevalence and risk factors of respi-ratory symptoms, atopic sensitisation and bronchial hyperresponsiveness (BHR) in young adults in Estonia and Sweden. </p><p>Following the protocol of the European Community Respiratory Health Survey (ECRHS), two random population samples, 3000 from Tartu, Estonia, and 3600 from Uppsala, Sweden were investigated with postal questionnaires. Random sub samples and subjects with asthma-like complaints were subsequently interviewed, BHR was tested and serum samples analysed for total and specific IgE and eosinophil cationic protein (ECP). In a separate study two methacholine challenge methods, using either Spira Elektro2 or Mefar MB3 as dosimeters, were compared on 28 mild to moderate asthma patients.</p><p>Symptoms of asthma and hay fever were less common in Esto-nia than in Sweden, while respiratory symptoms in general were more common in Estonia. The prevalence of BHR was high and the prevalence of atopy and the levels of serum ECP were low in Tartu. The differences between the two centres in the prevalence of atopy and allergic rhinitis diminished with age, indicating a probable cohort effect. Current smoking was a dominant risk factor for BHR and for all respiratory symptoms, except attacks of asthma, both in Tartu and Uppsala. There was some difference between risk factors for BHR and atopy between Tartu and Uppsala, mostly of social and environmental origin. The low prevalence of hay fever and asthma in Tartu seemed to be partly explained by a lack of awareness of atopy and allergic diseases in the Estonian society. The estimated cumulative dose causing a 20% fall in FEV₁ was smaller and the decline of FEV₁ /log(dose) curve steeper, using the Spira, compared to the Mefar protocol.</p>

<p>Urinary incontinence is a prevalent condition; nevertheless few women seek professional help. One aim of this study was to investigate all women aged 18-70 years in a Swedish community regarding (a) the prevalence rate and risk factors of urine leakage and (b) the quality of life for women with and without urine leakage, for women with stress incontinence versus urge incontinence, and for women with urine leakage who had or had not sought help. A second aim was to study all women aged 18-46 years from the same population four years later regarding (a) the quality of life and natural history of urine leakage, (b) why some women with persistent urine leakage seek help and others do not, and (c) how they deal with their urine leakage.</p><p>Every fourth woman aged 18-70 years was found to have urine leakage. The number of women with urine leakage increased with increasing age, the number of deliveries, the presence of urinary tract infection, and the use of oestrogen substitutions. Women with urine leakage had a lower quality of life in all eight dimensions of the SF-36 as compared with women without urine leakage. Furthermore, in women with urge incontinence the quality of life was lower compared with women with stress incontinence in all dimensions of the SF-36. Women with urine leakage who had sought help had lower quality of life in seven of eight SF-36 dimensions as compared with women with urine leakage who had not sought help.</p><p>At the four-year follow-up the quality of life had deteriorated in five of eight SF-36 dimensions in women aged 18-46 years with persistent urine leakage as compared with women with persistent continence. The mean annual incidence and remission rates of urine leakage were on the same low level (4%). Most women with slight or moderate long-term urine leakage had not sought professional help, largely because they considered their leakage a minor problem. Pelvic floor exercises was the most commonly used management method for all participants.</p>

<p>Eating disorders (ED) constitute a significant source of psychiatric morbidity and are an important public health concern in Western societies. Knowledge about risk factors for ED is crucial for early detection and implementation of preventive interventions. The aim of the present thesis was to examine the prevalence, incidence, correlates, and the risk factors for ED among 1,157 young adult women in the general population. The studies in the thesis used a prospective design with the potential of addressing methodological limitations in earlier research.</p><p>In Study I, conducted in 1997, the lifetime and point prevalence of DSM-IV-based diagnoses of ED was, respectively, 7.85% and 2.59%. Participants with ED reported higher body dissatisfaction, lower perceived social support from the family, and lower self-esteem compared to participants with no ED. In Study II, it was shown that highest relative use of escape-avoidance coping was reported among participants with ED, followed by dieting participants with no ED, and least among those neither dieting nor with ED. In Study III, (i.e., the follow-up in 1999), the point prevalence of ED was 3.15% and the cumulative 2-year first time incidence was .0105 (n=8). The total incidence group (n=34), as compared to the participants with no ED (controls, n=643), reported significantly lower premorbid self-esteem, and perceived social support from the family and higher body dissatisfaction, higher relative use of escape-avoidance coping, and dieting. Furthermore, the incidence group reported a significant increase in body dissatisfaction and relative use of escape-avoidance coping, and a significant decrease in self-esteem as compared to controls from 1997 to 1999. In Study IV, it was shown that the <i>Survey for Eating Disorders</i> is a reliable and valid self-report questionnaire for the screening of ED and case ascertainment. </p><p>In conclusion, it is suggested that premorbid low self-esteem, perceived low social support, high body dissatisfaction, high relative use of escape-avoidance coping, and dieting be regarded as risk factors for a later development of ED among young adult women. It is also proposed that more attention be devoted to these factors both in designing prevention interventions and in refining current treatments. </p>

<p>Headache is the most frequently reported pain in children and is associated with missed schooldays, anxiety, depressive symptoms and various physical symptoms. A secular trend of increasing headache prevalence has been suggested. Few studies have focused on tension-type headache among children from the general population. </p><p>The aims of this thesis were to describe the prevalence, incidence and prognosis of tension-type headache, migraine and overall headache in schoolchildren, to identify medical, psychological and social factors associated with these headache types, and to determine whether the prevalence of headache has increased over the last decades.</p><p>In 1997, 1850 schoolchildren aged 7-15 years from the city of Uppsala participated in a questionnaire study and 1371 (74.1%) responded. Out of these, a randomly selected, stratified sample of 131 children and their parents were interviewed. Three years later, 122 children from the interview sample replied to an identical headache questionnaire.</p><p>Compared with a similar study in 1955, a significantly lower proportion of schoolchildren reported no headache. The prevalence of tension-type headache increased with age and was significantly higher in girls than boys after the age of twelve. Similar age and gender differences were obtained for migraine. A higher proportion of girls reported frequent headache than boys. Children with headache, especially those with migraine, as well as their first-degree relatives suffered from other pains and physical symptoms more frequently than headache-free children and their first-degree relatives. Although the likelihood of experiencing the same headache diagnosis and symptoms at follow-up was high, about one fifth of children with migraine developed tension-type headache and vice versa. Female gender was a predictor of migraine and frequent headache a predictor of overall headache at follow-up. The estimated annual incidence for tension-type headache, migraine and overall headache was 81, 65 and 131 per 1000 children, respectively. </p><p>In conclusion, the results indicate that headache has become increasingly common among schoolchildren over the last decades. Prevention and treatment of headache is particularly important for girls since they have high prevalence of headache, frequent headache episodes and a poor outcome. In children with headache, diagnoses and treatment should be reassessed regularly and other pains should be asked about and treated as well. </p>

<p><b>Objectives</b>. To study medication utilization and adherence to prescribed therapy in a female population in central Sweden. To study usage of hormone replacement therapy (HRT) in this population and to assess how HRT users compare to non-users regarding symptom reporting, general health and other variables. To evaluate symptom prevalence adjusted for potential symptom affecting variables. </p><p><b>Material and methods</b>. A cross-sectional postal questionnaire study was performed in 1995 in seven counties in central Sweden. A questionnaire was sent to a random sample of 4,200 women aged 35-64, of whom 2,991 responded (71.2%). The questionnaire contained questions on psycho-socio-economic background, quality of life, self-reported health, height and weight, climacteric symptom prevalence, and menopausal status and symptoms. It also comprised questions on medication prescribed during the past year. </p><p><b>Results</b>. 40% used prescribed medication and 12% took four drugs or more. Age, educational level, self-rated health, and BMI remained significantly correlated to drug use in multivariate analysis. Adherence ranged from 15%-98% depending on age, a scheduled check-up, perceived importance of medication, concern about medication, taking cardiovascular and respiratory disease drugs. The highest adherence was found for hormonal medication the lowest for musculoskeletal medication. </p><p>HRT was used by 15% of the women. 13 % used other symptom relieving therapy. HRT users reported higher score of vasomotor symptoms, except for sweating during the daytime. </p><p>Prevalence of general symptoms did not necessarily increase with age. Especially symptoms related to stress-tension-depression decreased with age. Four different symptom prevalence patterns were found. </p><p><b>Conclusions</b>. Age, health status, educational level and body mass index (BMI) appear to affect drug use. Adherence to therapy is highest among elderly women who regard their medication as important and have a scheduled check-up. HRT relieves some vasomotor symptoms but does not affect other symptoms or self-rated health. Prevalence of symptoms related to Stress-tension-depression appears to decrease with age.</p>

Thesis (M. Pharm. (Pharmacy Practice))--North-West University, Potchefstroom Campus, 2009.

Coeliac disease (CD) is considered to be the result of a complex interplay of intrinsic (genetic) factors and variable extrinsic (environmental) factors. The complex background of CD explains its wide spectrum of clinical manifestations. For a very long time CD was considered more or less a disease of childhood, which was extremely rare in adults. Nowadays we know that CD is one of the most common food intolerance disorders. An epidemiological study of CD in a geographically defined area of Sweden (Paper1) showed a prevalence of 95.5/ 100 000 inhabitants. Among the associated diseases an especially high incidence of associated thyroid disease, 10.8% was observed. In a fifteen-year cohort follow up study of all CD-patients residing in the counties of Örebro and Linköping (Paper 2) the total mortality was increased with 38% (SMR 1.38 95% C.I. 0.31-0.83). This was mainly explained by a 48% increased death rate in ischemic heart disease, significant in patients over 65 years (SMR 1.58 95% C.I. 1.00-2.06). However, there was a 47 % lower risk of all malignancies (SIR 0.53 95% C.I. 0.31-0.83). A cohort of 22 consecutively biopsy-proven adult CD patients (Paper 3), were followed in respect of antibody titres from diagnosis and after 1, 3, 6, and 12 months on a gluten free diet (GFD). All antibody titres fell sharply within one month. Thus excluding a CD diagnosis serologically on a patient who has initiated a GFD by herself is not to recommend. In another cohort with CD patients (Paper IV) who were diagnosed 8-12 years earlier recommended and who were recommended, the reliability of diet history, serological and biochemical markers to predict the appearance of the small intestinal mucosa were analysed (Paper IV). The history of a strict GFD gave a predictive value of 88% of a mucosa in remission. The values of serological tests (AGA, EmA and tTG) to predict a mucosa in remission were 93% for all. In CD patients in remission gastro-intestinal symptoms were evaluated with the GSRS questionnaire. Subjects with CD reported significantly more GI-symptoms than a general population sample (p&lt;0.01). This was particularly true for women with CD who scored worse than female controls .By contrast men with CD reported no more symptoms than male controls.

To ensure that the resources of the health care sector are used effectively, new technologies need to be evaluated before implementation to examine if they generate health outcomes at an acceptable cost. This information can be collected by performing health economic evaluations in which the costs and health outcomes of different technologies are compared. To estimate the effect on health care budgets, there is also a need for information about the prevalence of the specific disease. Health outcomes in health economic evaluations are often measured in quality-adjusted life years (QALYs), which are calculated by multiplying the remaining life years after an intervention by a weight representing the health-related quality of life (HRQoL) during those years. This thesis aims to provide deeper knowledge of the health economic aspects of diabetic retinopathy (DR), an eye complication that affects patients with diabetes and may in the worst case lead to blindness. The focus is on three empirical and two methodological health economic research questions. The empirical research areas cover prevalence, costs, and HRQoL related to patients with DR. The methodological research questions explore the performance of different methods for estimation of QALY weights. This is of interest since it has been argued that the most common methods for estimating QALY weights may not capture all relevant vision-related aspects of quality of life. The analyses comprehend the validity of different methods for estimating QALY weights among patients with DR and if the results of one of the specific methods for estimating QALY weights, the time trade-off (TTO) exercise, are affected by patients’ subjective life expectancy (SLE). The empirical results demonstrate that DR is seen in approximately 40% and 30% of patients with type I and type II diabetes respectively, indicating that the prevalence of DR has decreased in both of these patient groups. Healthcare costs vary considerably between different severity levels of the disease, being estimated at €26, €257, €216, and €433 per patient per year for background retinopathy, proliferative diabetic retinopathy (PDR), diabetic macular oedema (DMO), and PDR combined with DMO respectively. Blindness due to DR is associated with an increased use of transportation services, caregiving services, and assistive technologies as well as productivity losses. This suggests that preventing the progression of DR may lower healthcare costs. Patients with vision impairment due to DR have lowered HRQoL in various dimensions, but the diagnosis of DR in itself has only a limited effect on HRQoL. The results on the methodological research questions show that different methods for estimating QALY weights seem to give different results. In comparison to EQ-5D, the Health Utilities Index Mark 3 (HUI-3) is the most sensitive method for detecting differences in QALY weights due to DR, and if decisions are to be made based on values from the general public, it can be recommended for use in cost-utility analyses of interventions directed at DR. Neither of the direct methods, TTO and the visual analogue scale, seems to be sensitive to differences in visual function, and more research is needed concerning the role of vision in people’s responses to the TTO exercises. In TTO exercises with time frames based on actuarial life expectancy, the patients’ SLE has an effect on their willingness to trade off years for full health. Thus, applying time frames deviating from patients’ SLE may result in biased QALY weights. Such bias may appear stronger within patient populations than within the general public. In conclusion, this thesis offers estimates for prevalence, costs, and QALY weights that can be used in economic evaluations of interventions directed at DR and as benchmarks for future DR research in order to follow up consequences of changes in diabetes care. In addition, it demonstrates that the choice of method for estimating QALY weights may have an impact on whether an intervention is considered cost-effective.

<p><font face="Arial"> <p align="left">The aim of the study was to determine the prevalence of and risk factors contributing to work-related musculoskeletal injuries amongst underground mine workers in Kitwe, Zambia.</p> </font></p>