Life expectancy of rigid gas permeable and high water content contact lenses

Purpose: The purpose of this study was to evaluate the life expectancy of various rigid gas permeable (RGP) lens materials used on a daily wear basis and to compare these results with the life expectancy of a matched group of soft lens wearers.

Methods: We retrospectively analyzed the records of 600 contact lens wearing patients (300 soft contact lens users and 300 RGP lens users) fit between September 1987 and September 1994. None of the subjects wore lenses on a planned replacement system. For the purposes of the study, RGP lenses were divided into three groups: <40 Dk were considered low-Dk; 41-89 Dk were considered mid-Dk; and >90 Dk were considered high-Dk. All soft lenses were high water content lenses (>60% water content). Lenses were included if they were replaced due to loss, breakage, deposition, or poor wettability but not if replaced because of changes in fit or prescription.

Results; The mean (+SD) life-spans of each lens type in months were 19.9 +/- 17 for low-Dk RGP lenses, 15.9 +/-13.3 for mid-Dk RGP lenses, 9.0+8.2 for high-Dk RGP lenses, and 6.4 +/-5.2 for high water content soft lenses. Statistical analysis using a one-way ANOVA on ranks indicated that these results were statistically significant (P< 0.0001).

Conclusions: Patients should be informed that high-Dk lenses (RGP and soft) provide substantial clinical benefits and that they should expect to replace high-Dk RGP lenses after approximately 6 months. This lends further credence to the use of high-Dk lenses on a planned replacement basis.

Life expectancy of type 1 diabetic patients during 1997-2010: a national Australian registry-based cohort study

AIMS/ HYPOTHESIS:
There is limited information about the impact of type 1 diabetes on life expectancy in a contemporary population. We examined the life expectancy of type 1 diabetic patients and explored the contribution of mortality at different ages and of different causes of death to years of life lost (YLL) compared with the general population.

METHODS:
We derived mortality rates of Australians with type 1 diabetes listed on the National Diabetes Services Scheme (NDSS) between 1997 and 2010 (n = 85,547) by linking the NDSS to the National Death Index. The Chiang method was used to estimate life expectancy and Arriaga's method was used to estimate the contributions of age-specific and cause-specific mortality to the YLL.

RESULTS:
A total of 5,981 deaths were identified during the 902,136 person-years of follow up. Type 1 diabetic patients had an estimated life expectancy at birth of 68.6 years (95% CI 68.1, 69.1), which was 12.2 years (95% CI 11.8, 12.7) less than that in the general population. The improvement in life expectancy at birth in 2004-2010 compared with 1997-2003 was similar for both type 1 diabetic patients (men, 1.9 years [95% CI 0.4, 3.3]; women, 1.5 years [95% CI 0.0, 3.2]) and the general population (men, 2.2 years; women, 1.4 years). Deaths at age <60 years accounted for 60% of the YLL from type 1 diabetes for men and 45% for women. The major contribution to YLL was mortality from endocrine and metabolic disease at age 10-39 years (men, 39-59%; women, 35-50%) and from circulatory disease at age ≥40 years (men, 43-75%; women, 34-75%).

CONCLUSIONS/ INTERPRETATION:
Data from 1997 to 2010 showed that Australian type 1 diabetic patients had an estimated loss in life expectancy at birth of 12.2 years compared with the general population.

Obesity in adulthood and its consequences for life expectancy: a life-table analysis

BACKGROUND: Overweight and obesity in adulthood are linked to an increased risk for death and disease. Their potential effect on life expectancy and premature death has not yet been described. OBJECTIVE: To analyze reductions in life expectancy and increases in premature death associated with overweight and obesity at 40 years of age. DESIGN: Prospective cohort study. SETTING: The Framingham Heart Study with follow-up from 1948 to 1990. PARTICIPANTS: 3457 Framingham Heart Study participants who were 30 to 49 years of age at baseline. MEASUREMENTS: Mortality rates specific for age and body mass index group (normal weight, overweight, or obese at baseline) were derived within sex and smoking status strata. Life expectancy and the probability of death before 70 years of age were analyzed by using life tables. RESULTS: Large decreases in life expectancy were associated with overweight and obesity. Forty-year-old female nonsmokers lost 3.3 years and 40-year-old male nonsmokers lost 3.1 years of life expectancy because of overweight. Forty-year-old female nonsmokers lost 7.1 years and 40-year-old male nonsmokers lost 5.8 years because of obesity. Obese female smokers lost 7.2 years and obese male smokers lost 6.7 years of life expectancy compared with normal-weight smokers. Obese female smokers lost 13.3 years and obese male smokers lost 13.7 years compared with normal-weight nonsmokers. Body mass index at ages 30 to 49 years predicted mortality after ages 50 to 69 years, even after adjustment for body mass index at age 50 to 69 years. CONCLUSIONS: Obesity and overweight in adulthood are associated with large decreases in life expectancy and increases in early mortality. These decreases are similar to those seen with smoking. Obesity in adulthood is a powerful predictor of death at older ages. Because of the increasing prevalence of obesity, more efficient prevention and treatment should become high priorities in public health.

Living healthier for longer: comparative effects of three heart-healthy behaviors on life expectancy with and without cardiovascular disease

BACKGROUND: Non-smoking, having a normal weight and increased levels of physical activity are perhaps the three key factors for preventing cardiovascular disease (CVD). However, the relative effects of these factors on healthy longevity have not been well described. We aimed to calculate and compare the effects of non-smoking, normal weight and physical activity in middle-aged populations on life expectancy with and without cardiovascular disease.

METHODS: Using multi-state life tables and data from the Framingham Heart Study (n = 4634) we calculated the effects of three heart healthy behaviours among populations aged 50 years and over on life expectancy with and without cardiovascular disease. For the life table calculations, we used hazard ratios for 3 transitions (No CVD to CVD, no CVD to death, and CVD to death) by health behaviour category, and adjusted for age, sex, and potential confounders.

RESULTS: High levels of physical activity, never smoking (men), and normal weight were each associated with 20-40% lower risks of developing CVD as compared to low physical activity, current smoking and obesity, respectively. Never smoking and high levels of physical activity reduced the risks of dying in those with and without a history of CVD, but normal weight did not. Never-smoking was associated with the largest gains in total life expectancy (4.3 years, men, 4.1 years, women) and CVD-free life expectancy (3.8 and 3.4 years, respectively). High levels of physical activity and normal weight were associated with lesser gains in total life expectancy (3.5 years, men and 3.4 years, women, and 1.3 years, men and 1.0 year women, respectively), and slightly lesser gains in CVD-free life expectancy (3.0 years, men and 3.1 years, women, and 3.1 years men and 2.9 years women, respectively). Normal weight was the only behaviour associated with a reduction in the number of years lived with CVD (1.8 years, men and 1.9 years, women).

CONCLUSIONS: Achieving high levels of physical activity, normal weight, and never smoking, are effective ways to prevent cardiovascular disease and to extend total life expectancy and the number of years lived free of CVD. Increasing the prevalence of normal weight could further reduce the time spent with CVD in the population.

Obesity in older adults and life expectancy with and without cardiovascular disease

BACKGROUND: The prevalence of overweight and obesity is increasing globally and is an established risk factor for cardiovascular disease (CVD). Our objective was to evaluate the impact of overweight and obesity on life expectancy and years lived with and without CVD in older adults.

METHODS: The study included 6636 individuals (3750 women) aged 55 years and older from the population-based Rotterdam Study. We developed multistate life tables by using prevalence, incidence rate and hazard ratios (HR) for three transitions (free-of-CVD-to-CVD, free-of-CVD-to-death and CVD-to-death), stratifying by the categories of body mass index (BMI) at baseline and adjusting for confounders.

RESULTS: During 12 years of follow-up, we observed 1035 incident CVD events and 1902 overall deaths. Obesity was associated with an increased risk of CVD among men (HR 1.57 (95% confidence interval (CI) 1.17, 2.11)) and women (HR 1.49 (95% CI 1.19, 1.86)), compared with normal weight individuals. Overweight and obesity were not associated with mortality in men and women without CVD. Among men with CVD, obesity compared with normal weight, was associated with a lower risk of mortality (HR 0.67 (95% CI 0.49, 0.90)). Overweight and obesity did not influence total life expectancy. However, obesity was associated with 2.6 fewer years (95% CI -4.8, -0.4) lived free from CVD in men and 1.9 (95% CI -3.3, -0.9) in women. Moreover, men and women with obesity lived 2.9 (95% CI 1.1, 4.8) and 1.7 (95% CI 0.6, 2.8) more years suffering from CVD compared with normal weight counterparts.

CONCLUSIONS: Obesity had no effect on total life expectancy in older individuals, but increased the risk of having CVD earlier in life and consequently extended the number of years lived with CVD. Owing to increasing prevalence of obesity and improved treatment of CVD, we might expect more individuals living with CVD and for a longer period of time.

Burden of diabetes in Australia: life expectancy and disability-free life expectancy in adults with diabetes.

AIMS/HYPOTHESIS: The aim of this work was to estimate the life expectancy (LE) and disability-free life expectancy (DFLE) for adults with and without diabetes. METHODS: The Chiang method and the adapted Sullivan method were used to estimate LE and DFLE by age and sex. Mortality data in 2011 were available from the National Diabetes Services Scheme for diabetes and from standard national mortality datasets for the general population. Data on prevalence of disability and severe or profound core activity limitation were derived from the 2012 Australian Survey of Disability, Ageing and Carers (SDAC). The definitions of disability used in the SDAC followed the International Classification of Functioning, Disability and Health. Data on diabetes prevalence were derived from the Australian Diabetes, Obesity and Lifestyle study. RESULTS: The estimated LE and DFLE (with 95% uncertainty interval [UI]) at age 50 years were 30.2 (30.0, 30.4) and 12.7 (11.5, 13.7) years, respectively, for men with diabetes, and the estimates were 33.9 (33.6, 34.1) and 13.1 (12.3, 13.9) years, respectively, for women with diabetes. The estimated loss of LE associated with diabetes at age 50 years was 3.2 (3.0, 3.4) years for men and 3.1 (2.9, 3.4) years for women, as compared with their counterparts without diabetes. The corresponding estimated loss of DFLE was 8.2 (6.7, 9.7) years for men and 9.1 (7.9, 10.4) years for women. Women with diabetes spent a greater number of absolute years and a greater proportion of their life with disability as compared with men with diabetes and women without diabetes. The gains in LE and DFLE across the whole population at age 50 years after hypothetically eliminating diagnosed diabetes were 0.6 (0.5, 0.6) years and 1.8 (1.0, 2.8) years. CONCLUSIONS/INTERPRETATION: In adults, diabetes results in a modest reduction in LE and a substantial reduction in DFLE. Efforts to identify the specific causes of disability and effective interventions are needed.

The distribution of quality of life in Australia

 Australians enjoy a relatively high degree of life quality as judged by comparative international statistics. This chapter reviews the distribution of Quality of Life in Australia by considering both the objective and subjective wellbeing (SWB) of the Australian population. The review begins with an overview of objective circumstances, including income, social support, and life expectancy. It also considers the distribution of trust. Two extant measures of the subjective wellbeing of Australians are then reviewed, and it is revealed that SWB has demonstrated remarkably stable properties over the last 12 years. This chapter provides some insight into the properties of the measures and the theoretical construct of Subjective Wellbeing to explain fluctuations that occur for different components of SWB. Further, this chapter considers the demographic characteristics that are common to Australians with higher and lower SWB and offers a basis of research upon which future measures of population wellbeing can be founded

A 'slow pace of life' in Australian old-endemic passerine birds is not accompanied by low basal metabolic rates

Life history theory suggests that species experiencing high extrinsic mortality rates allocate more resources toward reproduction relative to self-maintenance and reach maturity earlier ('fast pace of life') than those having greater life expectancy and reproducing at a lower rate ('slow pace of life'). Among birds, many studies have shown that tropical species have a slower pace of life than temperate-breeding species. The pace of life has been hypothesized to affect metabolism and, as predicted, tropical birds have lower basal metabolic rates (BMR) than temperate-breeding birds. However, many temperate-breeding Australian passerines belong to lineages that evolved in Australia and share 'slow' life-history traits that are typical of tropical birds. We obtained BMR from 30 of these 'old-endemics' and ten sympatric species of more recently arrived passerine lineages (derived from Afro-Asian origins or introduced by Europeans) with 'faster' life histories. The BMR of 'slow' temperate-breeding old-endemics was indistinguishable from that of new-arrivals and was not lower than the BMR of 'fast' temperate-breeding non-Australian passerines. Old-endemics had substantially smaller clutches and longer maximal life spans in the wild than new arrivals, but neither clutch size nor maximum life span was correlated with BMR. Our results suggest that low BMR in tropical birds is not functionally linked to their 'slow pace of life' and instead may be a consequence of differences in annual thermal conditions experienced by tropical versus temperate species.

Development and application of model of resource utilization, costs, and outcomes for stroke (MORUCOS): an Australian economic model for stroke.

Objectives: To outline the development, structure, data assumptions, and application of an Australian economic model for stroke (Model of Resource Utilization, Costs, and Outcomes for Stroke [MORUCOS]). Methods: The model has a linked spreadsheet format with four modules to describe the disease burden and treatment pathways, estimate prevalence-based and incidence-based costs, and derive life expectancy and quality of life consequences. The model uses patient-level, community-based, stroke cohort data and macro-level simulations. An interventions module allows options for change to be consistently evaluated by modifying aspects of the other modules. To date, model validation has included sensitivity testing, face validity, and peer review. Further validation of technical and predictive accuracy is needed. The generic pathway model was assessed by comparison with a stroke subtypes (ischemic, hemorrhagic, or undetermined) approach and used to determine the relative cost-effectiveness of four interventions. Results: The generic pathway model produced lower costs compared with a subtypes version (total average first-year costs/case AUD$15,117 versus AUD$17,786, respectively). Optimal evidence-based uptake of anticoagulation therapy for primary and secondary stroke prevention and intravenous thrombolytic therapy within 3 hours of stroke were more cost-effective than current practice (base year, 1997). Conclusions: MORUCOS is transparent and flexible in describing Australian stroke care and can effectively be used to systematically evaluate a range of different interventions. Adjusting results to account for stroke subtypes, as they influence cost estimates, could enhance the generic model.

Does financial education influence retirement savings? An examination of Australian employees

In order to ensure a financially secure retirement, Australians will need to plan and save for their retirement many decades before they retire.

The age pension, paid for out of Commonwealth government taxes is currently the backbone of the retirement system, but will not replace as much pre-retirement income in the future as it does today. Given the shift from the defined benefit style to the accumulation style, superannuation funds involve considerably more uncertainty, and as such, one might have thought that individuals would be saving more on their own. But personal saving outside of superannuation plans is virtually non-existent. Combine the retirement income crunch with the dramatic increase in life expectancy, and the need for careful retirement planning and sacrificing current consumption for later consumption becomes imperative for ensuring the financial security of older Australians. The hard question is whether individuals will be prepared to make the necessary sacrifices today to ensure a more secure financial future in retirement? This paper explores the willingness of individuals to make these sacrifices, and whether financial education can influence individuals in this difficult decision.

Emerging health issues: the widening challenge for population health promotion

The spectrum of tasks for health promotion has widened since the Ottawa Charter was signed. In 1986, infectious diseases still seemed in retreat, the potential extent of HIV/AIDS was unrecognized, the Green Revolution was at its height and global poverty appeared less intractable. Global climate change had not yet emerged as a major threat to development and health. Most economists forecast continuous improvement, and chronic diseases were broadly anticipated as the next major health issue. Today, although many broadly averaged measures of population health have improved, many of the determinants of global health have faltered. Many infectious diseases have emerged; others have unexpectedly reappeared. Reasons include urban crowding, environmental changes, altered sexual relations, intensified food production and increased mobility and trade. Foremost, however, is the persistence of poverty and the exacerbation of regional and global inequality. Life expectancy has unexpectedly declined in several countries. Rather than being a faint echo from an earlier time of hardship, these declines could signify the future. Relatedly, the demographic and epidemiological   transitions have faltered. In some regions, declining fertility has overshot that needed for optimal age structure, whereas elsewhere mortality increases have reduced population growth rates, despite continuing high fertility. Few, if any, Millennium Development Goals (MDG), including those for health and sustainability, seem achievable. Policy-makers generally misunderstand the link between environmental sustainability (MDG #7) and health. Many health workers also fail to realize that social cohesion and sustainability—maintenance of the Earth’s ecological and geophysical systems—is a necessary basis for health. In sum, these issues present an enormous challenge to health. Health promotion must address population health influences that transcend national boundaries and generations and engage with the development, human rights and environmental movements. The big task is to promote sustainable environmental and social conditions that bring enduring and equitable health gains.

Cancer patient preferences for communication of prognosis in the metastatic setting

PURPOSE: To identify preferences for and predictors of prognostic information among patients with incurable metastatic cancer. PATIENTS AND METHODS: One hundred twenty-six metastatic cancer patients seeing 30 oncologists at 12 outpatient clinics in New South Wales, Australia, participated in the study. Patients were diagnosed with incurable metastatic disease within 6 weeks to 6 months of recruitment. Patients completed a survey eliciting their preferences for prognostic information, including type, quantity, mode, and timing of presentation; anxiety and depression levels; and information and involvement preferences. RESULTS: More than 95% of patients wanted information about side effects, symptoms, and treatment options. The majority wanted to know longest survival time with treatment (85%), 5-year survival rates (80%), and average survival (81%). Words and numbers were preferred over pie charts or graphs. Fifty-nine percent (59%) wanted to discuss expected survival when first diagnosed with metastatic disease. Thirty-eight percent and 44% wanted to negotiate when expected survival and dying, respectively, were discussed. Patients with higher depression scores were more likely to want to know shortest time to live without treatment (P = .047) and average survival (P = .049). Lower depression levels were significantly associated with never wanting to discuss expected survival (P = .03). Patients with an expected survival of years were more likely to want to discuss life expectancy when first diagnosed with metastases (P = .02). CONCLUSION: Most metastatic cancer patients want detailed prognostic information but prefer to negotiate the extent, format, and timing of the information they receive from their oncologists.