Living conditions in old age: Coexisting disadvantages across life domains

The aim of this thesis was to analyse coexisting disadvantages in the older Swedish population. Coexisting disadvantages are those that occur simultaneously in various life domains. A person who simultaneously experiences several disadvantages may be particularly vulnerable and less well-equipped to manage daily life and may also need support from several different welfare service providers. Concerted actions may be needed for older people who experience not only physical health problems and functional limitations, but also other problems. Research that encompasses a wide range of living conditions provides a basis for setting political priorities and making political decisions. The studies in this thesis used data from two Swedish nationally representative surveys: the Level of Living Survey, which includes people aged 18 through 75, and the Swedish Panel Study of Living Conditions of the Oldest Old, which includes people aged 77 and older. Study I showed that the probability of experiencing coexisting disadvantages was higher in people 77 and older than in those aged 18 through 76. These age differences were partly driven by a high prevalence of physical health problems in older people. In all age groups, coexisting disadvantages were more common in women than men. The longitudinal analyses in Study II indicated that coexisting disadvantages in old age persist in some people but are temporary in others. Moreover, the results suggested a pattern of accumulating disadvantages: reporting one disadvantage in young old age (in particular, psychological health problems) increased the probability of reporting coexisting disadvantages in late old age.   Study III showed that physical health problems were a central component of coexisting disadvantages. The results also showed that being older; female; previously employed as a manual labourer; and divorced/separated, widowed or never married were associated with an increased probability of experiencing coexisting disadvantages. However, the experience of coexisting disadvantages differed: the groups associated with coexisting disadvantages tended to report different combinations of disadvantage. Study IV showed that the prevalence of coexisting disadvantages in those 77 and older increased slightly between 1992 and 2011. Physical health problems became more common over time, whereas limited ability to manage daily activities (ADL limitations), limited financial resources and limited political resources became less common. Associations between different disadvantages were found in all survey years, but certain associations changed over time. The results suggest that in general, the composition of coexisting disadvantages in the older population may have altered over time. In sum, results showed that coexisting disadvantages were associated with specific demographic and socio-economic groups. Physical health problems and psychological health problems were of particular importance to the accumulation and coexistence of disadvantages in old age.

Women's subjective and objective health over time : the role of psychosocial conditions and physiological stress responses

Today, health problems are likely to have a complex and multifactorial etiology, whereby psychosocial factors interact with behaviour and bodily responses. Women generally report more health problems than men. The present thesis concerns the development of women’s health from a subjective and objective perspective, as related to psychosocial living conditions and physiological stress responses. Both cross-sectional and longitudinal studies were carried out on a representative sample of women. Data analysis was based on a holistic person-oriented approach as well as a variable approach. In Study I, the women’s self-reported symptoms and diseases as well as self-rated general health status were compared to physician-rated health problems and ratings of the general health of the women, based on medical examinations. The findings showed that physicians rated twice as many women as having poor health compared to the ratings of the women themselves. Moreover, the symptom ”a sense of powerlessness” had the highest predictive power for self-rated general health. Study II investigated individual and structural stability in symptom profiles between adolescence and middle-age as related to pubertal timing. There was individual stability in symptom reporting for nearly thirty years, although the effect of pubertal timing on symptom reporting did not extend into middle-age. Study III explored the longitudinal and current influence of socioeconomic and psychosocial factors on women’s self-reported health. Contemporary factors such as job strain, low income, financial worries, and double exposure in terms of high job strain and heavy domestic responsibilities increased the risk for poor self-reported health in middle-aged women. In Study IV, the association between self-reported symptoms and physiological stress responses was investigated. Results revealed that higher levels of medically unexplained symptoms were related to higher levels of cortisol, cholesterol, and heart rate. The empirical findings are discussed in relation to existing models of stress and health, such as the demand-control model, the allostatic load model, the biopsychosocial model, and the multiple role hypothesis. It was concluded that women’s health problems could be reduced if their overall life circumstances were improved. The practical implications of this might include a redesign of the labour market giving women more influence and control over their lives, both at and away from work.

Is the association between late-life morbidity and disability attenuated over time? : Exploring the dynamic equilibrium of morbidity hypothesis

Context: There is evidence suggesting that the prevalence of disability in late life has declined over time while the prevalence of disabling chronic diseases has increased. The dynamic equilibrium of morbidity hypothesis suggests that these seemingly contradictory trends are due to the attenuation of the morbidity-disability link over time. The aim of this study was to empirically test this assumption.Methods: Data were drawn from three repeated cross-sections of SWEOLD, a population-based survey among the Swedish men and women ages 77 and older. Logistic regression models were fitted to assess the trends in the prevalence of Activities of Daily Living (ADL) disability, Instrumental ADL (IADL) disability, and selected groups of chronic conditions. The changes in the associations between chronic conditions and disabilities were examined in both multiplicative and additive models.Results: Between 1992 and 2011, the odds of ADL disability significantly declined among women whereas the odds of IADL disability significantly declined among men. During the same period, the prevalence of most chronic morbidities including multimorbidity went up. Significant attenuations of the morbidity-disability associations were found for cardiovascular diseases, metabolic disorders, poor lung function, psychological distress, and multimorbidity.Conclusion: In agreement with the dynamic equilibrium hypothesis, this study concludes that the associations between chronic conditions and disability among the Swedish older adults have largely waned over time.

Spring Phenology of Butterflies : The role of seasonal variation in life-cycle regulation

Animals and plants in temperate regions must adapt their life cycle to pronounced seasonal variation. The research effort that has gone into studying these cyclical life history events, or phenological traits, has increased greatly in recent decades. As phenological traits are often correlated to temperature, they are relevant to study in terms of understanding the effect of short term environmental variation as well as long term climate change. Because of this, changes in phenology are the most obvious and among the most commonly reported responses to climate change. Moreover, phenological traits are important for fitness as they determine the biotic and abiotic environment an individual encounters. Fine-tuning of phenology allows for synchronisation at a local scale to mates, food resources and appropriate weather conditions. On a between-population scale, variation in phenology may reflect regional variation in climate. Such differences can not only give insights to life cycle adaptation, but also to how populations may respond to environmental change through time. This applies both on an ecological scale through phenotypic plasticity as well as an evolutionary scale through genetic adaptation. In this thesis I have used statistical and experimental methods to investigate both the larger geographical patterns as well as mechanisms of fine-tuning of phenology of several butterfly species. The main focus, however, is on the orange tip butterfly, Anthocharis cardamines, in Sweden and the United Kingdom. I show a contrasting effect of spring temperature and winter condition on spring phenology for three out of the five studied butterfly species. For A. cardamines there are population differences in traits responding to these environmental factors between and within Sweden and the UK that suggest adaptation to local environmental conditions. All populations show a strong negative plastic relationship between spring temperature and spring phenology, while the opposite is true for winter cold duration. Spring phenology is shifted earlier with increasing cold duration. The environmental variables show correlations, for example, during a warm year a short winter delays phenology while a warm spring speeds phenology up. Correlations between the environmental variables also occur through space, as the locations that have long winters also have cold springs. The combined effects of these two environmental variables cause a complex geographical pattern of phenology across the UK and Sweden. When predicting phenology with future climate change or interpreting larger geographical patterns one must therefore have a good enough understanding of how the phenology is controlled and take the relevant environmental factors in to account. In terms of the effect of phenological change, it should be discussed with regards to change in life cycle timing among interacting species. For example, the phenology of the host plants is important for A. cardamines fitness, and it is also the main determining factor for oviposition. In summary, this thesis shows that the broad geographical pattern of phenology of the butterflies is formed by counteracting environmental variables, but that there also are significant population differences that enable fine-tuning of phenology according to the seasonal progression and variation at the local scale.