Benefits and harms of prostate specific antigen testing according to Australian guidelines.

Guidelines for prostate specific antigen (PSA) testing in Australia recommend that men at average risk of prostate cancer who have been informed of the benefits and harms, and who decide to undergo regular testing, should be offered testing every 2 years from 50 to 69 years. This study aimed to estimate the benefits and harms of regular testing in this context. We constructed Policy1-Prostate, a discrete event microsimulation platform of the natural history of prostate cancer and prostate cancer survival, and PSA testing patterns and subsequent management in Australia. The model was calibrated to pre-PSA (before 1985) prostate cancer incidence and mortality and validated against incidence and mortality trends from 1985 to 2011 and international trials. The model predictions were concordant with trials and Australian observed incidence and mortality data from 1985 to 2011. Out of 1000 men who choose to test according to the guidelines, 36 [21-41] men will die from prostate cancer and 126 [119-133] men will be diagnosed with prostate cancer, compared with 50 [47-54] and 94 [90-98] men who do not test, respectively. During the 20 years of active PSA testing, 32.3% [25.6%-38.8%] of all PSA-test detected cancers are overdiagnosed cases that is, 30 [21-42] out of 94 [83-107] PSA-test detected cancers. Australian men choosing to test with PSA every two years from 50 to 69 will reduce their risk of ever dying from prostate cancer and incur a risk of overdiagnosis: for every man who avoids dying from prostate cancer, two will be overdiagnosed with prostate cancer between 50 and 69 years of age. Australian men, with health professionals, can use these results to inform decision-making about PSA testing.

Pain and its interference with daily living in relation to cancer: a comparative population-based study of 16,053 cancer survivors and 106,345 people without cancer.

BACKGROUND: Pain is a common, debilitating, and feared symptom, including among cancer survivors. However, large-scale population-based evidence on pain and its impact in cancer survivors is limited. We quantified the prevalence of pain in community-dwelling people with and without cancer, and its relation to physical functioning, psychological distress, and quality of life (QoL). METHODS: Questionnaire data from participants in the 45 and Up Study (Wave 2, n = 122,398, 2012-2015, mean age = 60.8 years), an Australian population-based cohort study, were linked to cancer registration data to ascertain prior cancer diagnoses. Modified Poisson regression estimated age- and sex-adjusted prevalence ratios (PRs) for bodily pain and pain sufficient to interfere with daily activities (high-impact pain) in people with versus without cancer, for 13 cancer types, overall and according to clinical, personal, and health characteristics. The relation of high-impact pain to physical and mental health outcomes was quantified in people with and without cancer. RESULTS: Overall, 34.9% (5,436/15,570) of cancer survivors and 31.3% (32,471/103,604) of participants without cancer reported bodily pain (PR = 1.07 [95% CI = 1.05-1.10]), and 15.9% (2,468/15,550) versus 13.1% (13,573/103,623), respectively, reported high-impact pain (PR = 1.13 [1.09-1.18]). Pain was greater with more recent cancer diagnosis, more advanced disease, and recent cancer treatment. High-impact pain varied by cancer type; compared to cancer-free participants, PRs were: 2.23 (1.71-2.90) for multiple myeloma; 1.87 (1.53-2.29) for lung cancer; 1.06 (0.98-1.16) for breast cancer; 1.05 (0.94-1.17) for colorectal cancer; 1.04 (0.96-1.13) for prostate cancer; and 1.02 (0.92-1.12) for melanoma. Regardless of cancer diagnosis, high-impact pain was strongly related to impaired physical functioning, psychological distress, and reduced QoL. CONCLUSIONS: Pain is common, interfering with daily life in around one-in-eight older community-dwelling participants. Pain was elevated overall in cancer survivors, particularly for certain cancer types, around diagnosis and treatment, and with advanced disease. However, pain was comparable to population levels for many common cancers, including breast, prostate and colorectal cancer, and melanoma.

Fifty-year forecasts of daily smoking prevalence: can Australia reach 5% by 2030?

OBJECTIVE: To compare 50-year forecasts of Australian tobacco smoking rates in relation to trends in smoking initiation and cessation and in relation to a national target of ≤5% adult daily prevalence by 2030. METHODS: A compartmental model of Australian population daily smoking, calibrated to the observed smoking status of 229 523 participants aged 20-99 years in 26 surveys (1962-2016) by age, sex and birth year (1910-1996), estimated smoking prevalence to 2066 using Australian Bureau of Statistics 50-year population predictions. Prevalence forecasts were compared across scenarios in which smoking initiation and cessation trends from 2017 were continued, kept constant or reversed. RESULTS: At the end of the observation period in 2016, model-estimated daily smoking prevalence was 13.7% (90% equal-tailed interval (EI) 13.4%-14.0%). When smoking initiation and cessation rates were held constant, daily smoking prevalence reached 5.2% (90% EI 4.9%-5.5%) after 50 years, in 2066. When initiation and cessation rates continued their trajectory downwards and upwards, respectively, daily smoking prevalence reached 5% by 2039 (90% EI 2037-2041). The greatest progress towards the 5% goal came from eliminating initiation among younger cohorts, with the target met by 2037 (90% EI 2036-2038) in the most optimistic scenario. Conversely, if initiation and cessation rates reversed to 2007 levels, estimated prevalence was 9.1% (90% EI 8.8%-9.4%) in 2066. CONCLUSION: A 5% adult daily smoking prevalence target cannot be achieved by the year 2030 based on current trends. Urgent investment in concerted strategies that prevent smoking initiation and facilitate cessation is necessary to achieve 5% prevalence by 2030.

The 'hot zone policy' for colorectal cancer screening presents unique risks and opportunities for rural Australia.

OBJECTIVE: Colorectal cancer has geographic inequities in Australia, with higher mortality rates and lower participation in the National Bowel Cancer Screening Program (NBCSP) in remote and rural areas. The at-home kit is temperature-sensitive, necessitating a 'hot zone policy' (HZP); kits are not sent when an area's average monthly temperature is above 30°C. Australians in HZP areas are susceptible to potential screening disruptions but may benefit from well-timed interventions to improve participation. This study describes the demographics of HZP areas and estimates the impacts of potential screening changes. METHODS: The number of individuals in HZP areas was estimated, as well as correlations with remoteness, socio-economic and Indigenous status. The potential impacts of screening changes were estimated. RESULTS: Over a million eligible Australians live in HZP areas, which are more likely to be remote/rural, have lower socio-economic status and higher Indigenous populations. Predictive modelling estimates that any 3-month screening disruption would increase CRC mortality rates up to 4.1 times more in HZP areas vs unaffected areas, while targeted intervention could decrease mortality rates 3.4 times more in HZP areas. CONCLUSION: People living in affected areas would be negatively impacted by any NBCSP disruption, compounding existing inequities. However, well-timed health promotion could have a stronger impact.

Whole genome sequencing of mesorhizobia isolated from northern Canada.

Rhizobia are soil-dwelling bacteria that can form N2-fixing symbioses with legume plant species (Fabaceae). These bacteria are globally distributed; however, few studies have examined the genomics of rhizobia that live in cold environments. Here, we isolated and characterized three rhizobial strains from legume nodules collected at a pair of distant low Arctic tundra and boreal forest sites in northern Canada. Phylogenetic and average nucleotide identity measurements suggested that the three strains are members of the genus Mesorhizobium, and that each strain represents a novel genospecies. Intriguingly, whereas most mesorhizobia contain the classical determinants of nodulation and nitrogen fixation on their chromosome, whole genome sequencing revealed that all three strains carry these genes on large symbiotic megaplasmids of ∼750 to ∼1000 kb. Phylogenetic and sequence analyses of the common nodulation genes revealed highly conserved alleles amongst these northern mesorhizobia, leading us to propose that they belong to a novel symbiovar that we termed symbiovar oxytropis. Interestingly, these nod gene alleles are uncommon in mesorhizobia isolated from similar plant hosts in other climatic regions, suggesting potential functional adaptive differences.

Cancer incidence and cancer death in relation to tobacco smoking in a population-based Australian cohort study.

Tobacco smoke is a known carcinogen, but the magnitude of smoking-related cancer risk depends on country-specific, generational smoking patterns. We quantified cancer risk in relation to smoking in a population-based cohort, the 45 and Up Study (2006-2009) in New South Wales, Australia. Cox proportional hazards regressions estimated adjusted hazard ratios (HR) by self-reported smoking history at baseline (2006-2009) for incident, primary cancers via linkage to cancer registry data to 2013 and cancer death data to 2015. Among 229 028 participants aged ≥45 years, 18 475 cancers and 5382 cancer deaths occurred. Current-smokers had increased risks of all cancers combined (HR = 1.42, 95% confidence interval [CI], 1.34-1.51), cancers of the lung (HR = 17.66, 95%CI, 14.65-21.29), larynx (HR = 11.29, 95%CI, 5.49-23.20), head-and-neck (HR = 2.53, 95%CI, 1.87-3.41), oesophagus (HR = 3.84, 95%CI, 2.33-6.35), liver (HR = 4.07, 95%CI, 2.55-6.51), bladder (HR = 3.08, 95%CI, 2.00-4.73), pancreas (HR = 2.68, 95%CI, 1.93-3.71), colorectum (HR = 1.31, 95%CI, 1.09-1.57) and unknown primary site (HR = 3.26, 95%CI, 2.19-4.84) versus never-smokers. Hazards increased with increasing smoking intensity; compared to never-smokers, lung cancer HR = 9.22 (95%CI, 5.14-16.55) for 1-5 cigarettes/day and 38.61 (95%CI, 25.65-58.13) for >35 cigarettes/day. Lung cancer risk was lower with quitting at any age but remained higher than never-smokers for quitters aged >25y. By age 80y, an estimated 48.3% of current-smokers (41.1% never-smokers) will develop cancer, and 14% will develop lung cancer, including 7.7% currently smoking 1-5 cigarettes/day and 26.4% for >35 cigarettes/day (1.0% never-smokers). Cancer risk for Australian smokers is significant, even for 'light' smokers. These contemporary estimates underpin the need for continued investment in strategies to prevent smoking uptake and facilitate cessation, which remain key to reducing cancer morbidity and mortality worldwide.

Alcohol consumption, drinking patterns and cancer incidence in an Australian cohort of 226,162 participants aged 45 years and over.

BACKGROUND: Although overall alcohol consumption is known to increase the risk of a number of cancers internationally, evidence for Australia and evidence regarding the pattern of drinking and cancer risk is limited. METHODS: Adjusted hazard ratios (HR) and 95% confidence intervals (CI) for cancer risk in relation to overall alcohol consumption (drinks/week) and pattern of drinking were calculated using Cox proportional hazard regressions for 226,162 participants aged ≥45 years (2006-2009) in the 45 and Up Study, an Australian prospective cohort study. Incident primary cancer cases were ascertained by linkage to the New South Wales Cancer Registry to 2013 by the Centre for Health Record Linkage. RESULTS: Over a median of 5.4 years, 17,332 cancers were diagnosed. Increasing levels of alcohol intake were associated with increased risk of cancers of the upper aerodigestive tract (1.19; 1.10-1.29), mouth and pharynx (1.18; 1.08-1.29), oesophagus (1.22; 1.04-1.43), colorectum (1.09; 1.04-1.15), colon (1.13; 1.06-1.20), liver (1.22; 1.04-1.44) and breast (1.11; 1.02-1.21). Breast cancer risk was marginally associated with drinking pattern, with higher risk when intake was concentrated on 1-3 days/week compared to the same amount spread over 4-7 days (Pinteraction = 0.049). CONCLUSIONS: Alcohol consumption confers a significant risk of cancer, and drinking pattern may be independently related to breast cancer risk.

Disability, psychological distress and quality of life in relation to cancer diagnosis and cancer type: population-based Australian study of 22,505 cancer survivors and 244,000 people without cancer.

BACKGROUND: Improved survival means that cancer is increasingly becoming a chronic disease. Understanding and improving functional outcomes are critical to optimising survivorship. We quantified physical and mental health-related outcomes in people with versus without cancer, according to cancer type. METHODS: Questionnaire data from an Australian population-based cohort study (45 and Up Study (n = 267,153)) were linked to cancer registration data to ascertain cancer diagnoses up to enrolment. Modified Poisson regression estimated age- and sex-adjusted prevalence ratios (PRs) for adverse person-centred outcomes-severe physical functional limitations (disability), moderate/high psychological distress and fair/poor quality of life (QoL)-in participants with versus without cancer, for 13 cancer types. RESULTS: Compared to participants without cancer (n = 244,000), cancer survivors (n = 22,505) had greater disability (20.6% versus 12.6%, respectively, PR = 1.28, 95%CI = (1.25-1.32)), psychological (22.2% versus 23.5%, 1.05 (1.02-1.08)) and poor/fair QoL (15.2% versus 10.2%; 1.28 (1.24-1.32)). The outcomes varied by cancer type, being worse for multiple myeloma (PRs versus participants without cancer for disability 3.10, 2.56-3.77; distress 1.53, 1.20-1.96; poor/fair QoL 2.40, 1.87-3.07), lung cancer (disability 2.81, 2.50-3.15; distress 1.67, 1.46-1.92; poor/fair QoL 2.53, 2.21-2.91) and non-Hodgkin's lymphoma (disability 1.56, 1.37-1.78; distress 1.20, 1.05-1.36; poor/fair QoL 1.66, 1.44-1.92) and closer to those in people without cancer for breast cancer (disability 1.23, 1.16-1.32; distress 0.95, 0.90-1.01; poor/fair QoL 1.15, 1.05-1.25), prostate cancer (disability 1.11, 1.04-1.19; distress 1.09, 1.02-1.15; poor/fair QoL 1.15, 1.08-1.23) and melanoma (disability 1.02, 0.94-1.10; distress 0.96, 0.89-1.03; poor/fair QoL 0.92, 0.83-1.01). Outcomes were worse with recent diagnosis and treatment and advanced stage. Physical disability in cancer survivors was greater in all population subgroups examined and was a major contributor to adverse distress and QoL outcomes. CONCLUSIONS: Physical disability, distress and reduced QoL are common after cancer and vary according to cancer type suggesting priority areas for research, and care and support.

Pathways to a cancer-free future: A protocol for modelled evaluations to maximize the future impact of interventions on cervical cancer in Australia.

OBJECTIVE: Australia's HPV vaccination and HPV-based cervical screening programs are changing the landscape in cervical cancer prevention. We aim to identify areas which can make the biggest further impact on cervical cancer burden. This protocol describes the first stage of a program of work called Pathways-Cervix that aims to generate evidence from modelled evaluations of interventions across the cervical cancer spectrum. METHODS: Based on evidence from literature reviews and guidance from a multi-disciplinary Scientific Advisory Committee (SAC), the most relevant evaluations for prevention, diagnosis and treatment were identified. RESULTS: Priority evaluations agreed by the SAC included: increasing/decreasing and retaining vaccination uptake at the current level; vaccinating older women; increasing screening participation; methods for triaging HPV-positive women; improving the diagnosis of cervical intraepithelial neoplasia (CIN) and cancer; treating cervical abnormalities and cancer; and vaccinating women treated for CIN2/3 to prevent recurrence. Evaluations will be performed using a simulation model, Policy1-Cervix previously used to perform policy evaluations in Australia. Exploratory modelling of interventions using idealised scenarios will initially be conducted in single birth cohorts. If these have a significant impact on findings then evaluations with more realistic assumptions will be conducted. Promising strategies will be investigated further by multi-cohort simulations predicting health outcomes, resource use and cost outcomes. CONCLUSIONS: Pathways-Cervix will assess the relative benefits of strategies and treatment options in a systematic and health economic framework, producing a list of 'best buys' for future decision-making in cervical cancer control.

Evaluation of the benefits, harms and cost-effectiveness of potential alternatives to iFOBT testing for colorectal cancer screening in Australia.

The Australian National Bowel Cancer Screening Program (NBCSP) will fully roll-out 2-yearly screening using the immunochemical Faecal Occult Blood Testing (iFOBT) in people aged 50 to 74 years by 2020. In this study, we aimed to estimate the comparative health benefits, harms, and cost-effectiveness of screening with iFOBT, versus other potential alternative or adjunctive technologies. A comprehensive validated microsimulation model, Policy1-Bowel, was used to simulate a total of 13 screening approaches involving use of iFOBT, colonoscopy, sigmoidoscopy, computed tomographic colonography (CTC), faecal DNA (fDNA) and plasma DNA (pDNA), in people aged 50 to 74 years. All strategies were evaluated in three scenarios: (i) perfect adherence, (ii) high (but imperfect) adherence, and (iii) low adherence. When assuming perfect adherence, the most effective strategies involved using iFOBT (annually, or biennially with/without adjunct sigmoidoscopy either at 50, or at 54, 64 and 74 years for individuals with negative iFOBT), or colonoscopy (10-yearly, or once-off at 50 years combined with biennial iFOBT). Colorectal cancer incidence (mortality) reductions for these strategies were 51-67(74-80)% in comparison with no screening; 2-yearly iFOBT screening (i.e. the NBCSP) would be associated with reductions of 51(74)%. Only 2-yearly iFOBT screening was found to be cost-effective in all scenarios in context of an indicative willingness-to-pay threshold of A$50,000/life-year saved (LYS); this strategy was associated with an incremental cost-effectiveness ratio of A$2,984/LYS-A$5,981/LYS (depending on adherence). The fully rolled-out NBCSP is highly cost-effective, and is also one of the most effective approaches for bowel cancer screening in Australia.

Long-term deepened snow promotes tundra evergreen shrub growth and summertime ecosystem net CO2 gain but reduces soil carbon and nutrient pools.

Arctic climate warming will be primarily during winter, resulting in increased snowfall in many regions. Previous tundra research on the impacts of deepened snow has generally been of short duration. Here, we report relatively long-term (7-9 years) effects of experimentally deepened snow on plant community structure, net ecosystem CO2 exchange (NEE), and soil biogeochemistry in Canadian Low Arctic mesic shrub tundra. The snowfence treatment enhanced snow depth from 0.3 to ~1 m, increasing winter soil temperatures by ~3°C, but with no effect on summer soil temperature, moisture, or thaw depth. Nevertheless, shoot biomass of the evergreen shrub Rhododendron subarcticum was near-doubled by the snowfences, leading to a 52% increase in aboveground vascular plant biomass. Additionally, summertime NEE rates, measured in collars containing similar plant biomass across treatments, were consistently reduced ~30% in the snowfenced plots due to decreased ecosystem respiration rather than increased gross photosynthesis. Phosphate in the organic soil layer (0-10 cm depth) and nitrate in the mineral soil layer (15-25 cm depth) were substantially reduced within the snowfences (47-70 and 43%-73% reductions, respectively, across sampling times). Finally, the snowfences tended (p = .08) to reduce mineral soil layer C% by 40%, but with considerable within- and among plot variation due to cryoturbation across the landscape. These results indicate that enhanced snow accumulation is likely to further increase dominance of R. subarcticum in its favored locations, and reduce summertime respiration and soil biogeochemical pools. Since evergreens are relatively slow growing and of low stature, their increased dominance may constrain vegetation-related feedbacks to climate change. We found no evidence that deepened snow promoted deciduous shrub growth in mesic tundra, and conclude that the relatively strong R. subarcticum response to snow accumulation may explain the extensive spatial variability in observed circumpolar patterns of evergreen and deciduous shrub growth over the past 30 years.

Growth responses of the common arctic graminoid Eriophorum vaginatum to simulated grazing are independent of soil nitrogen availability.

Plant compensatory growth responses to herbivory are mediated by soil fertility and can have significant feedbacks that affect overall ecosystem nutrient cycling. The sedge Eriophorum vaginatum is the dominant graminoid in arctic mesic tundra, and is heavily consumed by caribou. Here, we compare the principal compensatory growth models in explaining the impact of a single episode of simulated caribou grazing at two clipping intensities on E. vaginatum total growing season shoot production, nitrogen concentrations, and nitrogen pools, over two successive years across a soil nitrogen fertilisation gradient. The clipping treatments had no effect on shoot production in the growing season when they were applied, but substantially reduced growth in the following year. Surprisingly, these reductions were consistent across all levels of soil nitrogen availability. The Limiting Resource Model can best explain this legacy effect on production because it predicts alternate compensatory growth responses depending on whether or not the herbivory affects availability of the resource that most limits plant growth. Accordingly, our results suggest that shoot compensatory growth in the year after the clipping was limited by some resource other than nitrogen-probably internal carbohydrate reserves or soil phosphorus. The clipping treatments initially enhanced shoot nitrogen concentrations and pools, but shoot nitrogen pools had decreased by the end of the second year due to the legacy effect of reduced shoot production. Finally, inflorescence removal substantially stimulated new shoot production in both years. Together, our results suggest that herbivory can significantly enhance temporal and local spatial heterogeneity in graminoid growth and nitrogen cycling.

Enhanced summer warming reduces fungal decomposer diversity and litter mass loss more strongly in dry than in wet tundra.

Many Arctic regions are currently experiencing substantial summer and winter climate changes. Litter decomposition is a fundamental component of ecosystem carbon and nutrient cycles, with fungi being among the primary decomposers. To assess the impacts of seasonal climatic changes on litter fungal communities and their functioning, Betula glandulosa leaf litter was surface-incubated in two adjacent low Arctic sites with contrasting soil moisture regimes: dry shrub heath and wet sedge tundra at Disko Island, Greenland. At both sites, we investigated the impacts of factorial combinations of enhanced summer warming (using open-top chambers; OTCs) and deepened snow (using snow fences) on surface litter mass loss, chemistry and fungal decomposer communities after approximately 1 year. Enhanced summer warming significantly restricted litter mass loss by 32% in the dry and 17% in the wet site. Litter moisture content was significantly reduced by summer warming in the dry, but not in the wet site. Likewise, fungal total abundance and diversity were reduced by OTC warming at the dry site, while comparatively modest warming effects were observed in the wet site. These results suggest that increased evapotranspiration in the OTC plots lowered litter moisture content to the point where fungal decomposition activities became inhibited. In contrast, snow addition enhanced fungal abundance in both sites but did not significantly affect litter mass loss rates. Across sites, control plots only shared 15% of their fungal phylotypes, suggesting strong local controls on fungal decomposer community composition. Nevertheless, fungal community functioning (litter decomposition) was negatively affected by warming in both sites. We conclude that although buried soil organic matter decomposition is widely expected to increase with future summer warming, surface litter decay and nutrient turnover rates in both xeric and relatively moist tundra are likely to be significantly restricted by the evaporative drying associated with warmer air temperatures.

Experimental warming alters migratory caribou forage quality.

Global declines in caribou and reindeer (Rangifer) populations have drawn attention to the myriad of stressors that these Arctic and boreal forest herbivores currently face. Arctic warming has resulted in increased tundra shrub growth and therefore Rangifer forage quantity. However, its effects on forage quality have not yet been addressed although they may be critical to Rangifer body condition and fecundity. We investigated the impact of 8 yrs of summer warming on the quality of forage available to the Bathurst caribou herd using experimental greenhouses (n = 5) located in mesic birch hummock tundra in the central Canadian Low Arctic. Leaf forage quality and digestibility characteristics associated with nutrients (nitrogen and phosphorus), phenolics, and fiber were measured on the deciduous shrub Betula glandulosa (an important Rangifer diet component) at six time points through the growing season, and on five other very common vascular plant and lichen species in late summer. Experimental warming reduced B. glandulosa leaf nitrogen concentrations by ~10% in both late June and mid-July, but not afterwards. It also reduced late summer forage quality of the graminoid Eriophorum vaginatum by increasing phenolic concentrations 38%. Warming had mixed effects on forage quality of the lichen Cetraria cucullata in that it increased nutrient concentrations and tended to decrease fiber contents, but it also increased phenolics. Altogether, these warming-induced changes in forage quality over the growing season, and response differences among species, highlight the importance of Rangifer adaptability in diet selection. Furthermore, the early season reduction in B. glandulosa nitrogen content is a particular concern given the importance of this time for calf growth. Overall, our demonstration of the potential for significant warming impacts on forage quality at critical times for these animals underscores the importance of effective Rangifer range conservation to ensure sufficient appropriate habitat to support adaptability in forage selection in a rapidly changing environment.

Widening socioeconomic disparity in lung cancer incidence among men in New South Wales, Australia, 1987-2011.

OBJECTIVE: We assessed the trends in lung cancer incidence over a 25-year period by socioeconomic groups for men in New South Wales (NSW), Australia. METHODS: Men diagnosed with lung cancer between 1987 and 2011 were divided into five quintiles according to an Index of Education and Occupation (IEO). We assessed relative socioeconomic differences over time by calculating age-standardized incidence ratios (SIRs) by 5-year period of diagnosis, and estimated absolute differences by comparing the observed and expected numbers of cases using the highest IEO quintile as the reference. RESULTS: Lung cancer incidence for men decreased from 1987 to 2011 for all IEO quintiles, with a greater rate of decline for men living in the highest IEO areas. Thus, the relative disparity increased significantly over the 25-year period (P=0.0006). For example, the SIR for the lowest IEO quintile increased from 1.28 during 1987-1991 to 1.74 during 2007-2011. Absolute differences also increased with the proportion of " potentially preventable" cases doubling from 14.5% in 1987-1991 to 30.2% in 2007-2011. CONCLUSIONS: Despite the overall decline in lung cancer incidence among men in NSW over the past 25 years, there was a significant increase in disparity across socioeconomic areas in both relative and absolute terms.

Vegetation-associated impacts on arctic tundra bacterial and microeukaryotic communities.

The Arctic is experiencing rapid vegetation changes, such as shrub and tree line expansion, due to climate warming, as well as increased wetland variability due to hydrological changes associated with permafrost thawing. These changes are of global concern because changes in vegetation may increase tundra soil biogeochemical processes that would significantly enhance atmospheric CO2 concentrations. Predicting the latter will at least partly depend on knowing the structure, functional activities, and distributions of soil microbes among the vegetation types across Arctic landscapes. Here we investigated the bacterial and microeukaryotic community structures in soils from the four principal low Arctic tundra vegetation types: wet sedge, birch hummock, tall birch, and dry heath. Sequencing of rRNA gene fragments indicated that the wet sedge and tall birch communities differed significantly from each other and from those associated with the other two dominant vegetation types. Distinct microbial communities were associated with soil pH, ammonium concentration, carbon/nitrogen (C/N) ratio, and moisture content. In soils with similar moisture contents and pHs (excluding wet sedge), bacterial, fungal, and total eukaryotic communities were correlated with the ammonium concentration, dissolved organic nitrogen (DON) content, and C/N ratio. Operational taxonomic unit (OTU) richness, Faith's phylogenetic diversity, and the Shannon species-level index (H') were generally lower in the tall birch soil than in soil from the other vegetation types, with pH being strongly correlated with bacterial richness and Faith's phylogenetic diversity. Together, these results suggest that Arctic soil feedback responses to climate change will be vegetation specific not just because of distinctive substrates and environmental characteristics but also, potentially, because of inherent differences in microbial community structure.

The strategy dynamics of collective systems: Underlying hindrances beyond two-actor coordination.

Engineering systems, characterized by their high technical complexity and societal intricacies, require a strategic design approach to navigate multifaceted challenges. Understanding the circumstances that affect strategic action in these systems is crucial for managing complex real-world challenges. These challenges go beyond localized coordination issues and encompass intricate dynamics, requiring a deep understanding of the underlying structures impacting strategic behaviors, the interactions between subsystems, and the conflicting needs and expectations of diverse actors. Traditional optimization and game-theoretic approaches to guide individual and collective decisions need adaptation to capture the complexities of these design ecosystems, particularly in the face of increasing numbers of decision-makers and various interconnections between them. This paper presents a framework for studying strategic decision-making processes in collective systems. It tackles the combinatorial complexity and interdependencies inherent in large-scale systems by representing strategic decision-making processes as binary normal-form games, then dissects and reinterprets them in terms of multiple compact games characterized by two real-numbered structural factors and classifies them across four strategy dynamical domains associated with different stability conditions. We provide a mathematical characterization and visual representation of emergent strategy dynamics in games with three or more actors intended to facilitate its implementation by researchers and practitioners and elicit new perspectives on design and management for optimizing systems-of-systems performance. We conclude this paper with a discussion of the opportunities and challenges of adopting this framework within and beyond the context of engineering systems.

Parent's awareness of, and influence on, their 14-17-year-old child's vaping and smoking behaviours; an analysis of 3242 parent-child pairs in Australia.

BACKGROUND: Vaping by young people in Australia is a rapidly emerging public health issue. Evidence shows that parental behaviours and attitudes can play a key role in influencing adolescent behaviours. Considering the health harms of vaping and evidence that it can be a gateway to tobacco smoking for never-smokers, it is important to understand whether parents' smoking and vaping behaviours influence their teenage children's smoking and vaping behaviours. METHODS: Online cross-sectional surveys as part of the Generation Vape study, conducted in Australia in 2021/2022, were used to assess parents' influence on, and awareness of, one of their 14-17-year-old child's vaping and smoking behaviours. Participants were 3242 parents and 3242 14-17-year-old teenage children. RESULTS: The risk of vaping and smoking uptake among 14-17-year-old teenagers was 42% (p = 0.003) and 97% (p < 0.001) higher, respectively, if their parent was an ever-vaper. The risk of vaping and smoking uptake among teenagers was 81% (p < 0.001) and 159% (p < 0.001) higher, respectively, if their parent was an ever-smoker. Parents of teenagers who have not vaped were considerably better at correctly predicting this (97% correct) than parents of teenagers who have vaped (70% correct). Compared to parents, teenagers tended to have less agreement with statements suggesting vaping is unsafe or harmful, and more agreement with statements suggesting vaping is relatively safe. CONCLUSIONS: Parental smoking and vaping behaviours are associated with those of their children. Hence, it is important that both tobacco and vaping control policies and interventions are designed to influence behaviours of all demographics, consistent with the evidence.

The association between vaping and subsequent initiation of cigarette smoking in young Australians from age 12 to 17 years: a retrospective cohort analysis using cross-sectional recall data from 5114 adolescents.

OBJECTIVE: The objective of this study was to estimate the association between vaping and subsequent initiation of smoking among Australian adolescents and explore the impact of design and analytical methods in previous studies. METHODS: We conducted a retrospective cohort analysis of cross-sectional data from 5114 Australian adolescents aged 14-17 recalling information on smoking and vaping initiation from age 12 to 17. The outcome was smoking initiation, analysed with negative-binomial regression to estimate incidence rate ratios (IRRs) for vape status (ever-vaped vs never-vaped) as a time-varying exposure. We also re-analysed using the methods of previous studies not accounting for the time-varying nature of e-cigarette exposure. RESULTS: Participants (n=5114) were retrospectively followed for 20478 person-years. After adjusting for socio-demographic variables and proxy measures of common liabilities for vaping and smoking, the rate of smoking initiation for those who ever-vaped was nearly 5 times that of those who never-vaped (IRR=4.9; 95% confidence interval: [3.9, 6.0], p<0.001), with IRRs considerably higher at younger ages. Not accounting for the time-varying nature of e-cigarette exposure in re-analysis attenuated the estimated IRR by 44%. CONCLUSIONS: Controlled analyses indicate that vaping markedly increases the risk of subsequent smoking initiation among Australian adolescents from age 12 to 17, with those aged 12, 13, and 14 bearing an alarmingly disproportionate burden of the elevated risk. Additionally, the relative risk of future smoking due to vaping may have been underestimated in other studies due to methodological differences. IMPLICATIONS FOR PUBLIC HEALTH: Our findings highlight the need for public health interventions and strict e-cigarette access laws.