title: Mortality, morbidity and population health dynamics

authors: Cheung, Jit

abstract: This thesis is concerned with the dynamics of the health of populations with low levels of mortality, using the non-Maori population in New Zealand as a case study. The primary objective is to study patterns and trends in mortality and morbidity, their interactions, and their implications for the future. 

The key questions addressed in this thesis are central to the future evolution of population health. Given the significant declines in mortality, especially those at older ages that have occurred over the last two decades, will mortality declines at advanced ages continue much longer? Or will mortality become increasingly compressed into a narrow range of ages at death? Moreover, what are the implications for morbidity trends and any indications at present of future trends in population health? Will increased survivorship be accompanied by long periods in ill-health, or will morbidity move in tandem with mortality, or will durations surviving but in ill-health actually decrease? 

The thesis first establishes a theoretical platform by reviewing and synthesising transition theories and empirical observations into a general framework to guide the understanding of population health dynamics. It also forges a theoretical linkage between variations in the individual senescence process, which underpin the validity of demographic models of mortality and morbidity, and their population level manifestations. These theoretical extensions provide the context for an evaluation of contemporary theories on mortality trends and changes in morbidity in relation to mortality. 

In addition to using long term historical data spanning over a century and complemented by a population-based true cohort approach, this thesis also makes methodological advancements by adapting and developing a tool, known as health expectancy, for the analysis of population health. In particular, a new measure termed “hospitalisation expectancy” is developed. It integrates data on hospital utilisation and mortality to yield a summary measure of population health.

The empirical study documents the shift in the forces of mortality of non-Maori, from younger to older ages, and from communicable causes of death to chronic degenerative diseases. Results of the mortality analysis by cohorts show that while there may be some indications of a future trend towards mortality compression, further increases in life expectancy at birth can be realistically expected. Empirical evidence of compression of morbidity is found in the trends of hospitalisation and the patterns of severe forms of disability. The causes of morbidity are becoming more diversified, dominated by non-lethal conditions; whereas the causes of mortality are becoming increasingly compressed into a few chronic conditions, namely cancers and cardiovascular diseases. It is also established in this thesis that the older population represents a heterogeneous group in terms of levels of susceptibility to ill-health. An empirical method for identifying heterogeneity is developed to show non-Maori inter-cohort differences in this property. 

Later in the thesis, a cohort based mortality projection of non-Maori at adult ages is undertaken. Various scenarios of morbidity responses to the projected mortality changes, incorporating the leading theories on future morbidity changes, are then modelled. To conclude the thesis, the implications for policy of further mortality declines at older age among an increasingly heterogeneous population are discussed.

text: Mortality, morbidity and population health dynamics This thesis is concerned with the dynamics of the health of populations with low levels of mortality, using the non-Maori population in New Zealand as a case study. The primary objective is to study patterns and trends in mortality and morbidity, their interactions, and their implications for the future. 

The key questions addressed in this thesis are central to the future evolution of population health. Given the significant declines in mortality, especially those at older ages that have occurred over the last two decades, will mortality declines at advanced ages continue much longer? Or will mortality become increasingly compressed into a narrow range of ages at death? Moreover, what are the implications for morbidity trends and any indications at present of future trends in population health? Will increased survivorship be accompanied by long periods in ill-health, or will morbidity move in tandem with mortality, or will durations surviving but in ill-health actually decrease? 

The thesis first establishes a theoretical platform by reviewing and synthesising transition theories and empirical observations into a general framework to guide the understanding of population health dynamics. It also forges a theoretical linkage between variations in the individual senescence process, which underpin the validity of demographic models of mortality and morbidity, and their population level manifestations. These theoretical extensions provide the context for an evaluation of contemporary theories on mortality trends and changes in morbidity in relation to mortality. 

In addition to using long term historical data spanning over a century and complemented by a population-based true cohort approach, this thesis also makes methodological advancements by adapting and developing a tool, known as health expectancy, for the analysis of population health. In particular, a new measure termed “hospitalisation expectancy” is developed. It integrates data on hospital utilisation and mortality to yield a summary measure of population health.

The empirical study documents the shift in the forces of mortality of non-Maori, from younger to older ages, and from communicable causes of death to chronic degenerative diseases. Results of the mortality analysis by cohorts show that while there may be some indications of a future trend towards mortality compression, further increases in life expectancy at birth can be realistically expected. Empirical evidence of compression of morbidity is found in the trends of hospitalisation and the patterns of severe forms of disability. The causes of morbidity are becoming more diversified, dominated by non-lethal conditions; whereas the causes of mortality are becoming increasingly compressed into a few chronic conditions, namely cancers and cardiovascular diseases. It is also established in this thesis that the older population represents a heterogeneous group in terms of levels of susceptibility to ill-health. An empirical method for identifying heterogeneity is developed to show non-Maori inter-cohort differences in this property. 

Later in the thesis, a cohort based mortality projection of non-Maori at adult ages is undertaken. Various scenarios of morbidity responses to the projected mortality changes, incorporating the leading theories on future morbidity changes, are then modelled. To conclude the thesis, the implications for policy of further mortality declines at older age among an increasingly heterogeneous population are discussed.

year: 1999

title: Looking beyond the number of repetitions: An observational cross-sectional study on calf raise test outcomes in children aged 10–17 years

authors: Hébert-Losier, Kim

subjects: Ankle

abstract: Aims: The calf raise test (CRT) assesses plantarflexor strength and endurance, but normative data for children are scarce. Furthermore, contradictions exist on which factors are associated with total repetitions, with repetitions being the only metric considered. We quantified three of the main CRT outcomes (repetitions, total work, and peak height) in children 10–17 years and explored their relationship with various factors. Methods: Healthy children (n = 165, 50.3% female) completed single-legged calf raises on a 10° incline, once on each leg. Test outcomes were extracted using the valid and reliable Calf Raise application. Results: CRT outcomes were not significantly different between legs (p ≥ .19). The only covariates significantly associated with outcomes based on stepwise quantile regressions were body mass index centile for repetitions, meeting physical activity recommendations for total work and peak height, and age for total work. Outcomes did not significantly differ based on sex or maturation. Median values were around 26 for repetitions, 640–1460 J for total work (age dependent), and 10.1 cm for peak height for children meeting physical activity recommendations. Conclusion: Children who were older, had lower body mass indices, and were more active exhibited superior CRT outcomes. Meeting physical activity recommendations appears beneficial for plantarflexor function and should continue to be prioritized in children.

text: Looking beyond the number of repetitions: An observational cross-sectional study on calf raise test outcomes in children aged 10–17 years Aims: The calf raise test (CRT) assesses plantarflexor strength and endurance, but normative data for children are scarce. Furthermore, contradictions exist on which factors are associated with total repetitions, with repetitions being the only metric considered. We quantified three of the main CRT outcomes (repetitions, total work, and peak height) in children 10–17 years and explored their relationship with various factors. Methods: Healthy children (n = 165, 50.3% female) completed single-legged calf raises on a 10° incline, once on each leg. Test outcomes were extracted using the valid and reliable Calf Raise application. Results: CRT outcomes were not significantly different between legs (p ≥ .19). The only covariates significantly associated with outcomes based on stepwise quantile regressions were body mass index centile for repetitions, meeting physical activity recommendations for total work and peak height, and age for total work. Outcomes did not significantly differ based on sex or maturation. Median values were around 26 for repetitions, 640–1460 J for total work (age dependent), and 10.1 cm for peak height for children meeting physical activity recommendations. Conclusion: Children who were older, had lower body mass indices, and were more active exhibited superior CRT outcomes. Meeting physical activity recommendations appears beneficial for plantarflexor function and should continue to be prioritized in children.

year: 2024-09-23

title: Applying Kaupapa Māori Processes to Documentary Film.

authors: Waititi, Kahurangi Rora

subjects: Maori documentary

abstract: This thesis explores the application of Kaupapa Māori processes to documentary filmmaking through practiced-led research. The need for this research came to light through the experience of witnessing unacceptable behaviour shown by film crews towards kaumātua who were attending the 2006 28th Māori Battalion Reunion. In reflecting on this experience and considering my own filming experience as a person with a Te Ao Māori background, the basis for this argument was conceived. This thesis argues that there are alternative ways in which filming can be conducted by considering processes that already exist within Māori practices and philosophies.          

This Thesis, therefore, investigates alternative processes of filming that have developed from a Kaupapa Māori perspective through practical filming experience.  An historical overview of the relationship between Māori, media and filming practices have been provided to give context to this discussion.  The application of Kaupapa Māori processes to film was considered through the use of Marae protocol and philosophies. The application of these concepts was supported by the creative research which was utilised by referencing specific examples. The reader is, therefore, instructed to refer to the DVD in the front of the thesis as referenced in the written text.

text: Applying Kaupapa Māori Processes to Documentary Film. This thesis explores the application of Kaupapa Māori processes to documentary filmmaking through practiced-led research. The need for this research came to light through the experience of witnessing unacceptable behaviour shown by film crews towards kaumātua who were attending the 2006 28th Māori Battalion Reunion. In reflecting on this experience and considering my own filming experience as a person with a Te Ao Māori background, the basis for this argument was conceived. This thesis argues that there are alternative ways in which filming can be conducted by considering processes that already exist within Māori practices and philosophies.          

This Thesis, therefore, investigates alternative processes of filming that have developed from a Kaupapa Māori perspective through practical filming experience.  An historical overview of the relationship between Māori, media and filming practices have been provided to give context to this discussion.  The application of Kaupapa Māori processes to film was considered through the use of Marae protocol and philosophies. The application of these concepts was supported by the creative research which was utilised by referencing specific examples. The reader is, therefore, instructed to refer to the DVD in the front of the thesis as referenced in the written text.

year: 2007