Determinants and treatment of hypertension in South Africans: The first demographic and health survey

Objectives: To identify the groups of patients with high prevalence and poor control of hypertension in South Africa. Methods: In the first national Demographic and Health Survey, 12 952 randomly selected South Africans, aged 15 years and older were surveyed. Trained interviewers completed questionnaires on socio-demographic characteristics, lifestyle and the management of hypertension. This cross-sectional survey also included blood pressure, height and weight measurements. Logistic regression analyses identified the determinants of hypertension and the treatment status in this dataset. Results: A high risk of hypertension was associated with less than tertiary education, older age groups, overweight and obese people, using alcohol in excess, and a family history of stroke and hypertension. Rural Africans had the lowest risk of hypertension, which was significantly higher in obese African women than in women with normal body mass index. Improved hypertension control was found in the wealthy, women, older persons, being Asian, and having medical insurance. Conclusions: Rural African people had lower hypertension prevalence rates than the other groups. The poorer, younger men, without health insurance had the worst level of hypertension control.

Increasing the confidence and knowledge of occupational therapy and physiotherapy students when communicating with people with aphasia: A pre–post intervention study

This study investigated occupational therapy and physiotherapy students' level of confidence and knowledge of strategies for communicating with people with aphasia (PWA) before and after a communication partner-training (CPT) program. Twenty-eight physiotherapy and occupational therapy students participated in a pre–post CPT program. Students completed a customized mixed-methods questionnaire before and after the intervention. The CPT program involved a lecture about effective communication strategies followed by a conversation with PWA to practice strategies learnt. Before CPT, students were not confident with the possibility of communicating with PWA. Students demonstrated rudimentary knowledge of supported conversation, identifying a maximum of five strategies for communicating effectively with PWA. Following intervention, students demonstrated increased confidence. Students' knowledge of effective communication strategies improved, with students identifying a maximum of 16 suitable strategies post-training. The results suggest that occupational therapy and physiotherapy students have potential to benefit from practical training in supported communication with PWA, which may assist them during placements in clinical settings with neurological patients or subsequent employment.

Napping, development and health from 0 to 5 years : a systematic review

Background Duration and quality of sleep affect child development and health. Encouragement of napping in preschool children has been suggested as a health-promoting strategy. Objectives The aim of this study is to assess evidence regarding the effects of napping on measures of child development and health. Design This study is a systematic review of published, original research articles of any design. Subjects Children aged 0–5 years. Method Electronic database search was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and assessment of research quality was carried out following a Grading of Recommendations, Assessment, Development and Evaluations (GRADE) protocol. Results Twenty-six articles met inclusion criteria. These were of heterogeneous quality; all had observational designs (GRADE-low). Development and health outcomes included salivary cortisol, night sleep, cognition, behaviour, obesity and accidents. The findings regarding cognition, behaviour and health impacts were inconsistent, probably because of variation in age and habitual napping status of the samples. The most consistent finding was an association between napping and later onset, shorter duration and poorer quality of night sleep, with evidence strongest beyond the age of 2 years. Limitations Studies were not randomised. Most did not obtain data on the children's habitual napping status or the context of napping. Many were reliant on parent report rather than direct observation or physiological measurement of sleep behaviour. Conclusions The evidence indicates that beyond the age of 2 years napping is associated with later night sleep onset and both reduced sleep quality and duration. The evidence regarding behaviour, health and cognition is less certain. There is a need for more systematic studies that use stronger designs. In preschool children presenting with sleep problems clinicians should investigate napping patterns.

Enhanced preference for high-fat foods following a simulated night shift

Objectives Shift workers are prone to obesity and associated co-morbidities such as diabetes and cardiovascular disease. Sleep restriction associated with shift work results in dramatic endocrine and metabolic effects that predispose shift workers to these adverse health consequences. While sleep restriction has been associated with increased caloric intake, food preference may also play a key role in weight gain associated with shift work. This study examined the impact of an overnight simulated night shift on food preference. Methods Sixteen participants [mean 20.1, standard deviation (SD) 1.4 years; 8 women] underwent a simulated night shift and control condition in a counterbalanced order. On the following morning, participants were provided an opportunity for breakfast that included high- and low-fat food options (mean 64.8% and 6.4% fat, respectively). Results Participants ate significantly more high-fat breakfast items after the simulated night shift than after the control condition [167.3, standard error of the mean (SEM 28.7) g versus 211.4 (SEM 35.6) g; P=0.012]. The preference for high-fat food was apparent among the majority of individuals following the simulated night shift (81%), but not for the control condition (31%). Shift work and control conditions did not differ, however, in the total amount of food or calories consumed. Conclusions A simulated night shift leads to preference for high-fat food during a subsequent breakfast opportunity. These results suggest that food choice may contribute to weight-related chronic health problems commonly seen among night shift workers.

Patient safety and the RCA: A document analysis

This research examined the function of Queensland Health's Root Cause Analysis (RCA) to improve patient safety through an investigation of patient harm events where permanent harm and preventable death, Severity Assessment Code 1, were the outcome of healthcare. Unedited and highly legislated RCAs from across Queensland Health public hospitals from 2009, 2010 and 2011 comprised the data. A document analysis revealed the RCAs opposed organisational policy and dominant theoretical directives. If we accept the prevailing assumption that patient harm is a systemic issue, then the RCA is failing to address harm events in healthcare.

Nintendo Wii Fit as an adjunct to physiotherapy following lower limb fractures: Preliminary feasibility, safety and sample size considerations

Objective The Nintendo Wii Fit integrates virtual gaming with body movement, and may be suitable as an adjunct to conventional physiotherapy following lower limb fractures. This study examined the feasibility and safety of using the Wii Fit as an adjunct to outpatient physiotherapy following lower limb fractures, and reports sample size considerations for an appropriately powered randomised trial. Methodology Ambulatory patients receiving physiotherapy following a lower limb fracture participated in this study (n = 18). All participants received usual care (individual physiotherapy). The first nine participants also used the Wii Fit under the supervision of their treating clinician as an adjunct to usual care. Adverse events, fracture malunion or exacerbation of symptoms were recorded. Pain, balance and patient-reported function were assessed at baseline and discharge from physiotherapy. Results No adverse events were attributed to either the usual care physiotherapy or Wii Fit intervention for any patient. Overall, 15 (83%) participants completed both assessments and interventions as scheduled. For 80% power in a clinical trial, the number of complete datasets required in each group to detect a small, medium or large effect of the Wii Fit at a post-intervention assessment was calculated at 175, 63 and 25, respectively. Conclusions The Nintendo Wii Fit was safe and feasible as an adjunct to ambulatory physiotherapy in this sample. When considering a likely small effect size and the 17% dropout rate observed in this study, 211 participants would be required in each clinical trial group. A larger effect size or multiple repeated measures design would require fewer participants.

Population health planning and health promotion: Opportunities and challenges to improve social determinants

Complex social factors and health issues challenge equitable health outcomes for many people, in particular those living in marginalised communities. Primary health care promises solutions through population health and health promotion approaches to improve social conditions (determinants) affecting health with emphasis on change at systems levels. Yet short-term efficiency focus policy decisions without long-term planning can undermine the effectiveness of primary health care. The workshop goal is to explore opportunities and share ideas about population health planning in Primary Health Networks and other community health care settings, so as to draw out opportunities, challenges and forward thinking health planning and health promotion strategies.

Psychological resources, their social antecedents, and association with well-being and health behaviour in early adulthood

The success of entering work life, young people s psychological resources and self-reported well-being were studied in a longitudinal setting from a life-span developmental-contextual perspective in early adulthood. The aim was to analyse how psychosocial characteristics in early childhood and adolescence predict successful entrance into work life, how this is associated with well-being, and to assess the level of psychological resources such as dispositional optimism, personal meaning of work and coping in early adulthood. The role of these and social support, in the relationship between regional factors (such as place of residence and migration), self-reported health and life satisfaction was studied. The association between a specific coping strategy, i.e. eating and drinking in a stressful situation and eating habits, was studied to demonstrate how coping is associated with health behaviour. Multivariate methods, including binary logistic regression analyses and ANOVA, were used for statistical analyses. The subjects were members of the Northern Finland 1966 Birth Cohort, which consists of all women and men born in 1966 in the two northernmost provinces of Finland (n= 12,058). The most recent follow-up, at the age of 31 years when 11,637 subjects were alive, took place in 1997-1998. The results show, first, that social resources in the childhood family and adolescence school achievement predict entrance into the labour market. Secondly, psychosocial resources were found to mediate the relationship between migration from rural to urban areas, and subjective well-being. Thirdly, psychological resources at entrance into the labour market were found to develop from early infancy on. They are, however, influenced later by work history. Fourthly, stress-related eating and drinking, as a way of coping, was found to be directly associated with unhealthy eating habits and alcohol use. Gender differences were found in psychosocial resources predicting, and being associated with success in entering the labour market. For men, the role of attitudinal and psychological factors seems to be especially important in entrance into work life and in the development of psychological resources. For women, academic attainment was more important for successfully entering work life, and lack of emotional social support was a risk factor for stress-related eating only among women. Stress-related eating and drinking habits were predicted by a long history of unemployment as well as a low level of education among both genders, but not excluding an academic degree among men. The results emphasize the role of childhood psychosocial factors in preventing long-term unemployment and in enhancing psychological well-being in early adulthood. Success in entering work life, in terms of continuous work history, plays a crucial role for well-being and the amount of psychological resources in early adulthood. The results emphasize the crucial role of enhancing psychological resources for promoting positive health behaviour and diminishing regional differences in subjective well-being.

Living arrangements and health

In line with major demographic changes in other Northern European and North American countries and Australia, being nonmarried is becoming increasingly common in Finland, and the proportion of cohabiters and of persons living alone has grown in recent decades. Official marital status no longer reflects an individual s living arrangement, as single, divorced and widowed persons may live alone, with a partner, with children, with parents, with siblings, or with unrelated persons. Thus, more than official marital status, living arrangements may be a stronger discriminator of one s social bonds and health. The general purpose of this study was to deepen our current understanding of the magnitude, trends, and determinants of ill health by living arrangements in the Finnish working-age population. Distinct measures of different dimensions of poor health, as well as an array of associated factors, provided a comprehensive picture of health differences by living arrangements and helped to assess the role of other factors in the interpretation of these differences . Mortality analyses were based on Finnish census records at the end of 1995 linked with cause-of-death registers for 1996 2000. The data included all persons aged 30 and over. Morbidity analyses were based on two comparable cross-sectional studies conducted twenty years apart (the Mini-Finland Survey in 1978 80 and the Health 2000 Survey in 2000 01). Both surveys were based on nationally representative samples of Finns aged 30 and over, and benefited from high participation rates. With the exception of mortality analyses, this study focused on health differences among the working-age population (mortality in age groups 30-64 and 65 and over, self-rated health and mental health in the age group 30-64, and unhealthy alcohol use in the age group 30-54). Compared with all nonmarried groups, married men and women exhibited the best health in terms of mortality, self-rated health, mental health and unhealthy alcohol use. Cohabiters did not differ from married persons in terms of self-rated health or mental health, but did exhibit excess unhealthy alcohol use and high mortality, particularly from alcohol-related causes. Compared with the married, persons living alone or with someone other than a partner exhibited elevated mortality as well as excess poor mental health and unhealthy alcohol use. By all measures of health, men and women living alone tended to be in the worst position. Over the past twenty years, SRH had improved least among single men and women and widowed women, and most among cohabiting women. The association between living arrangements and health has many possible explanations. The health-related selection theory suggests that healthy people are more likely to enter and maintain a marriage or a consensual union than those who are unhealthy (direct selection) or that a variety of health-damaging behavioural and social factors increase the likelihood of ill health and the probability of remaining without a partner or becoming separated from one s partner (indirect selection). According to the social causation theory, marriage or cohabitation has a health-promoting effect, whereas living alone or with others than a partner has a detrimental effect on health. In this study, the role of other factors that are mainly assumed to reflect selection, appeared to be rather modest. Social support, which reflects social causation, contributed only modestly to differences in unhealthy alcohol use by living arrangements, but had a larger effect on differences in poor mental health. Socioeconomic factors and health-related behaviour, which reflect both selection and causation, appeared to play a more important role in the excess poor health of cohabiters and of persons living alone or with someone other than a partner, than of married persons. Living arrangements were strongly connected to various dimensions of ill health. In particular, alcohol consumption appeared to be of great importance in the association between living arrangements and health. To the extent that the proportion of nonmarried persons continues to grow and their health does not improve at the same rate as that of married persons, the challenges that currently nonmarried persons pose to public health will likely increase.

Trust, participation and health among ageing people : A cross-sectional cohort study of men and women born in 1926-30, 1936-40, and 1946-50 in the Lahti region, southern Finland

The purpose of the present study was to explore the associations between good self-rated health and economic and social factors in different regions among ageing people in the Päijät-Häme region in southern Finland. The data of this study were collected in 2002 as part of the research and development project Ikihyvä 2002 2012 (Good Ageing in Lahti region GOAL project). The baseline data set consisted of 2,815 participants born in 1926 30, 1936 40, and 1946 50. The response rate was 66 %. According to the previous studies, trust in other people and social participation as the main aspects of social capital are associated with self-rated health. In addition, socioeconomic position (SEP) and self-rated health are associated, but all SEP indicators do not have identical associations with health. However, there is a lack of knowledge of the health associations and regional differences with these factors, especially among ageing people. Regarding these questions, the present study gives new information. According to the results of this study, self-perceived adequacy of income was significantly associated with good self-rated health, especially in the urban areas. Similar associations were found in the rural areas, though education was also considered an important factor. Adequacy of income was an even stronger predictor of good health than the actual income. Women had better self-rated health than men only in the urban areas. The youngest respondents had quite equally better self-rated health than the others. Social participation and access to help when needed were associated with good self-rated health, especially in the urban area and the sparsely populated rural areas. The result was comparable in the rural population centres. The correlation of trust with self-rated health was significant in the urban area. High social capital was associated with good self-rated health in the urban area. The association was quite similar in the other areas, though it was statistically insignificant. High social capital consisted of co-existent high social participation and high trust. The association of traditionalism (low participation and high trust) with self-rated health was also substantial in the urban area. The associations of self-rated health with low social capital (low participation and low trust) and the miniaturisation of community (high participation and low trust) were less significant. From the forms of single participation, going to art exhibitions, theatre, movies, and concerts among women, and studying and self-development among men were positively related to self-rated health. Unexpectedly, among women, active participation in religious events and voluntary work was negatively associated with self-rated health. This may indicate a coping method with ill-health. As a whole, only minor variations in self-rated health were found between the areas. However, the significance of the factors associated with self-rated health varied according to the areas. Economic factors, especially self-perceived adequacy of income was strongly associated with good self-rated health. Also when adjusting for economic and several other background factors social factors (particularly high social capital, social participation, and access to help when needed) were associated with self-rated health. Thus, economic and social factors have a significant relation with the health of the ageing, and improving these factors may have favourable effects on health among ageing people.

Socioeconomic Status, Occupational Factors and Lifestyle as Predictors of Hospitalisation for Back Disorders

The aim of this dissertation was to examine the determinants of severe back disorders leading to hospital admission in Finland. First, back-related hospitalisations were considered from the perspective of socioeconomic status, occupation, and industry. Secondly, the significance of psychosocial factors at work, sleep disturbances, and such lifestyle factors as smoking and overweight was studied as predictors of hospitalisation due to back disorders. Two sets of data were used: 1) the population-based data comprised all occupationally active Finns aged 25-64, and included hospitalisations due to back disorders in 1996 and 2) a cohort of employees followed up from 1973 to 2000 having been hospitalised due to back disorders. The results of the population-based study showed that people in physically strenuous industries and occupations, such as agriculture and manufacturing, were at an increased risk of being hospitalised for back disorders. The lowest hospitalisation rates were found in sedentary occupations. Occupational class and the level of formal education were independently associated with hospitalisation for back disorders. This stratification was fairly consistent across age-groups and genders. Men had a slightly higher risk of becoming hospitalised compared with women, and the risk increased with age among both genders. The results of the prospective cohort study showed that psychosocial factors at work such as low job control and low supervisor support predicted subsequent hospitalisation for back disorders even when adjustments were made for occupational class and physical workload history. However, psychosocial factors did not predict hospital admissions due to intervertebral disc disorders; only admissions due to other back disorders. Smoking and overweight predicted, instead, only hospitalisation for intervertebral disc disorders. These results suggest that the etiological factors of disc disorders and other back disorders differ from each other. The study concerning the association of sleep disturbances and other distress symptoms with hospitalisation for back disorders revealed that sleep disturbances predicted subsequent hospitalisation for all back disorders after adjustment for chronic back disorders and recurrent back symptoms at baseline, as well as for work-related load and lifestyle factors. Other distress symptoms were not predictive of hospitalisation.

Physical activity, fitness, abdominal obesity, and cardiovascular risk factors in Finnish men and women : The National FINRISK 2002 Study

Physical inactivity, low cardiorespiratory fitness, and abdominal obesity are direct and mediating risk factors for cardiovascular disease (CVD). The results of recent studies suggest that individuals with higher levels of physical activity or cardiorespiratory fitness have lower CVD and all-cause mortality than those with lower activity or fitness levels regardless of their level of obesity. The interrelationships of physical activity, fitness, and abdominal obesity with cardiovascular risk factors have not been studied in detail. The aim of this study was to investigate the associations of different types of leisure time physical activity and aerobic fitness with cardiovascular risk factors in a large population of Finnish adults. In addition, a novel aerobic fitness test was implemented and the distribution of aerobic fitness was explored in men and women across age groups. The interrelationships of physical activity, aerobic fitness and abdominal obesity were examined in relation to cardiovascular risk factors. This study was part of the National FINRISK Study 2002, which monitors cardiovascular risk factors in a Finnish adult population. The sample comprised 13 437 men and women aged 25 to 74 years and was drawn from the Population Register as a stratified random sample according to 10-year age groups, gender and area. A separate physical activity study included 9179 subjects, of whom 5 980 participated (65%) in the study. At the study site, weight, height, waist and hip circumferences, and blood pressure were measured, a blood sample was drawn, and an aerobic fitness test was performed. The fitness test estimated maximal oxygen uptake (VO2max) and was based on a non-exercise method by using a heart rate monitor at rest. Waist-to-hip ratio (WHR) was calculated by dividing waist circumference with hip circumference and was used as a measure of abdominal obesity. Participants filled in a questionnaire on health behavior, a history of diseases, and current health status, and a detailed 12-month leisure time physical activity recall. Based on the recall data, relative energy expenditure was calculated using metabolic equivalents, and physical activity was divided into conditioning, non-conditioning, and commuting physical activity. Participants aged 45 to 74 years were later invited to take part in a 2-hour oral glucose tolerance test with fasting insulin and glucose measurements. Based on the oral glucose tolerance test, undiagnosed impaired glucose tolerance and type 2 diabetes were defined. The estimated aerobic fitness was lower among women and decreased with age. A higher estimated aerobic fitness and a lower WHR were independently associated with lower systolic and diastolic blood pressure, lower total cholesterol and triglyceride levels, and with higher high-density lipoprotein (HDL) cholesterol and HDL to total cholesterol ratio. The associations of the estimated aerobic fitness with diastolic blood pressure, triglycerides, and HDL to total cholesterol ratio were stronger in men with a higher WHR. High levels of conditioning and non-conditioning physical activity were associated with lower high-sensitivity C-reactive protein (CRP) levels. High levels of conditioning and overall physical activities were associated with lower insulin and glucose levels. The associations were stronger among women than men. A better self-rated physical fitness was associated with a higher estimated aerobic fitness, lower CRP levels, and lower insulin and glucose levels in men and women. In each WHR third, the risk of impaired glucose tolerance and type 2 diabetes was higher among physically inactive individuals who did not undertake at least 30 minutes of moderate-intensity physical activity on five days per week. These cross-sectional data show that higher levels of estimated aerobic fitness and regular leisure time physical activity are associated with a favorable cardiovascular risk factor profile and that these associations are present at all levels of abdominal obesity. Most of the associations followed a dose-response manner, suggesting that already low levels of physical activity or fitness are beneficial to health and that larger improvements in risk factor levels may be gained from higher activity and fitness levels. The present findings support the recommendation to engage regularly in leisure time physical activity, to pursue a high level of aerobic fitness, and to prevent abdominal obesity.

Physical activity and health related quality of life

Background Research on the relationship between Health Related Quality of Life (HRQoL) and physical activity (PA), to date, have rarely investigated how this relationship differ across objective and subjective measures of PA. The aim of this paper is to explore the relationship between HRQoL and PA, and examine how this relationship differs across objective and subjective measures of PA, within the context of a large representative national survey from England. Methods Using a sample of 5,537 adults (40–60 years) from a representative national survey in England (Health Survey for England 2008), Tobit regressions with upper censoring was employed to model the association between HRQoL and objective, and subjective measures of PA controlling for potential confounders. We tested the robustness of this relationship across specific types of PA. HRQoL was assessed using the summary measure of health state utility value derived from the EuroQol-5 Dimensions (EQ-5D) whilst PA was assessed via subjective measure (questionnaire) and objective measure (accelerometer- actigraph model GT1M). The actigraph was worn (at the waist) for 7 days (during waking hours) by a randomly selected sub-sample of the HSE 2008 respondents (4,507 adults – 16 plus years), with a valid day constituting 10 hours. Analysis was conducted in 2010. Results Findings suggest that higher levels of PA are associated with better HRQoL (regression coefficient: 0.026 to 0.072). This relationship is consistent across different measures and types of PA although differences in the magnitude of HRQoL benefit associated with objective and subjective (regression coefficient: 0.047) measures of PA are noticeable, with the former measure being associated with a relatively better HRQoL (regression coefficient: 0.072). Conclusion Higher levels of PA are associated with better HRQoL. Using an objective measure of PA compared with subjective shows a relatively better HRQoL.

Cultural safety and diversity: Refocusing our energies in mental health nursing practice, education and research

INTRODUCTION AND BACKGROUND: This presentation draws on a body of work assessing cultural safety's potential to generate change in mental health nursing research (Cox and Simpson 2015), in education and in clinical practice (Cox and Taua 2013, 2016; Happell, Cowin, Roper, Lakeman & Cox 2013). It presents evidence to suggest that cultural safety could resolve the conceptual confusion surrounding culture and diversity in nursing curricular, in clinical and in research practice. The history and nature of mental health work recommend cultural safety to focus attention on diversity, power imbalance, racism, cultural dominance, and structural inequality, identified as barriers and tensions in clinical practice and in service user participation. Cultural safety gives mental health nursing a well theorized and articulated model, which is evolving to improve practice into the future. DESCRIPTION: This work involved an immersion in the literature on cultural safety and the Service User Research movement. It draws on 5 months' work with a service users' research group in the UK and reflections on 9 years of cultural safety teaching. POLICY/PRACTICE CHANGE: This work provokes a crucial change of emphasis from locating the source of issues in the diversity of people to locating it in how society responds to diversity: a change from individualistic to systemic concerns. IMPLICATIONS FOR MENTAL HEALTH NURSING: Cultural safety in clinical practice, education, and research is specifically concerned with awareness of the impact of systemic workplace cultures and with staff cultural self-awareness to bring about cultural change and person-centred care of individuals' unique needs and aspirations within their life context.

Circadian Rhythm Disruptions and Health

The doctoral thesis defined connections between circadian rhythm disruptions and health problems. Sleep debt, jet-lag, shift work, as well as transitions into and out of the daylight saving time may lead to circadian rhythm disruptions. Disturbed circadian rhythm causes sleep deprivation and decrease of mood and these effects may lead to higher accident rates and trigger mental illnesses. Circadian clock genes are involved in the regulation of the cell cycle and metabolism and thus unstable circadian rhythmicity may also lead to cancer development. In publications I-III it was explored how transitions into and out of the daylight saving time impact the sleep efficiency and the rest-activity cycles of healthy individuals. Also it was explored whether the effect of transition is different in fall as compared to spring, and whether there are subgroup specific differences in the adjustment to transitions into and out of daylight saving time. The healthy participants of studies I-III used actigraphs before and after the transitions and filled in the morningness-eveningness and seasonal pattern assessment questionnaires. In publication IV the incidence of hospital-treated accidents and manic episodes was explored two weeks before and two weeks after the transitions into and out of the daylight saving time in years 1987-2003. In publication V the relationship between circadian rhythm disruption and the prevalence of Non-Hodgkin lymphoma was studied. The study V consisted of all working aged Finns who participated in the national population census in 1970. For our study, all the cancers diagnosed during the years 1971-1995 were extracted from the Finnish Cancer Register and linked with the 1970 census files. In studies I-III it was noticed that transitions into and out of the daylight saving time disturbs the sleep-wake cycle and the sleep efficiency of the healthy participants. We also noticed that short sleepers were more sensitive than long sleepers for sudden changes in the circadian rhythm. Our results also indicated that adaptation to changes in the circadian rhythm is potentially sex, age and chronotype-specific. In study IV no significant increase in the occurrence of hospital treated accidents or manic episodes was noticed. However, interesting observations about the seasonal fluctuation of the occurrence rates of accidents and manic episodes were made. Study V revealed that there might be close relationship between circadian rhythm disruption and cancer. The prevalence of Non-Hodgkin lymphoma was the highest among night workers. The five publications included in this thesis together point out that disturbed circadian rhythms may have adverse effect on health. Disturbed circadian rhythms decrease the quality of sleep and weaken the sleep-wake cycle. A continuous circadian rhythm disruption may also predispose individuals to cancer development. Since circadian rhythm disruptions are common in modern society they might have a remarkable impact on the public health. Thus it is important to continue circadian rhythm research so that better prevention and treatment methods can be developed. Keywords: Circadian rhythm, daylight saving time, manic episodes, accidents, Non-Hodgkin lymphoma 11