Cost-effectiveness analysis of screening for lung cancer with low dose spiral CT (computed tomography) in the Australian setting

Introduction:
Low dose spiral computed tomography (CT) is a sensitive screening tool for lung cancer that is currently being evaluated in both non-randomised studies and randomised controlled trials.
Methods:
We conducted a quantitative decision analysis using a Markov model to determine whether, in the Australian setting, offering spiral CT screening for lung cancer to high risk individuals would be cost-effective compared with current practice. This exploratory analysis was undertaken predominantly from the perspective of the government as third-party funder. In the base-case analysis, the costs and health outcomes (life-years saved and quality-adjusted life years) were calculated in a hypothetical cohort of 10,000 male current smokers for two alternatives: (1) screen for lung cancer with annual CT for 5 years starting at age 60 year and treat those diagnosed with cancer or (2) no screening and treat only those who present with symptomatic cancer.
Results:
For male smokers aged 60–64 years, with an annual incidence of lung cancer of 552 per 100,000, the incremental cost-effectiveness ratio was $57,325 per life-year saved and $105,090 per QALY saved. For females aged 60–64 years with the same annual incidence of lung cancer, the cost-effectiveness ratio was $51,001 per life-year saved and $88,583 per QALY saved. The model was used to examine the relationship between efficacy in terms of the expected reduction in lung cancer mortality at 7 years and cost-effectiveness. In the base-case analysis lung cancer mortality was reduced by 27% and all cause mortality by 2.1%. Changes in the estimated proportion of stage I cancers detected by screening had the greatest impact on the efficacy of the intervention and the cost-effectiveness. The results were also sensitive to assumptions about the test performance characteristics of CT scanning, the proportion of lung cancer cases overdiagnosed by screening, intervention rates for benign disease, the discount rate, the cost of CT, the quality of life in individuals with early stage screen-detected cancer and disutility associated with false positive diagnoses. Given current knowledge and practice, even under favourable assumptions, reductions in lung cancer mortality of less than 20% are unlikely to be cost-effective, using a value of $50,000 per life-year saved as the threshold to define a “cost-effective” intervention.
Conclusion:
The most feasible scenario under which CT screening for lung cancer could be cost-effective would be if very high-risk individuals are targeted and screening is either highly effective or CT screening costs fall substantially.

The temporal sequence of allergic sensitization and onset of infantile eczema

Background: Eczema is commonly associated with sensitization in infants, but the causative role of sensitization in the development of eczema has been questioned.

Objective: To determine if allergic sensitization increases the risk of developing eczema, or alternatively, if eczema increases the risk of developing allergic sensitization.

Methods: We used data from the Melbourne Atopy Cohort Study, a prospective birth cohort of 552 infants with a family history of atopic disease. The main outcomes were risk of developing eczema from 6 months to 7 years of age in asymptomatic infants; and risk of developing sensitization, as measured by skin prick tests to milk, egg white, peanut, house dust mite, rye grass pollen and cat extracts, in previously unsensitized infants.

Results: Sensitization to food extracts at 6 months was associated with an increased risk of developing eczema [hazard ratio (HR) 1.63, 95% confidence interval 1.13–2.35] up to 7 years of age, after excluding infants with eczema in the first 6 months. However, eczema in the first 6 months was also associated with increased risk of new sensitization at both 1 year (HR 2.34, 1.38–3.98) and 2 years (HR 3.47, 1.65–7.32).

Conclusion: In some infants, sensitization precedes and predicts the development of eczema, while in others eczema precedes and predicts the development of sensitization. This indicates that there are multiple pathways to atopic eczema.

Breaking up prolonged sitting reduces postprandial glucose and insulin responses

OBJECTIVE--Observational studies show breaking up prolonged sitting has beneficial associations with cardiometabolic risk markers, but intervention studies are required to investigate causality. We examined the acute effects on postprandial glucose and insulin levels of uninterrupted sitting compared with sitting interrupted by brief bouts of light- or moderate-intensity walking.

RESEARCH DESIGN AND METHODS--Overweight/obese adults (n = 19), aged 45-65 years, were recruited for a randomized three-period, three-treatment acute crossover trial: I) uninterrupted sitting; 2) seated with 2-min bouts of light-intensity walking every 20 rain; and 3) seated with 2-min bouts of moderate-intensity walking every 20 min. A standardized test drink was provided after an initial 2-h period of uninterrupted sitting. The positive incremental area under curves (iAUC) for glucose and insulin (mean [95% CI]) for the 5 h after the test drink (75 g glucose, 50 g fat) were calculated for the respective treatments.

RESULTS--The glucose iAUC (mmol/L) x h after both activity-break conditions was reduced (light: 5.2 [4.1-6.6]; moderate: 4.9 [3.8-6.1]; both P < 0.01) compared with uninterrupted sitting (6.9 [5.5-8.7]). Insulin iAUC (pmol/L) x h was also reduced with both activity-break conditions (light: 633.6 [552.4-727.1]; moderate: 637.6 [555.5-731.9], P < 0.0001) compared with uninterrupted sitting (828.6 [722.0-950.9]).

CONCLUSIONS--Interrupting sitting time with short bouts of light- or moderate-intensity walking lowers postprandial glucose and insulin levels in overweight/obese adults. This may improve glucose metabolism and potentially be an important public health and clinical intervention strategy for reducing cardiovascular risk.

Effect of manufacturing method and aging environment on painted automotive carbon fibre composite surfaces

In this paper, the effect of various aging environments on the painted surface finish of unidirectional carbon fibre composite laminates, manufactured by autoclave and a novel out-of-autoclave technique was investigated. Laminates were exposed to water immersion, 95 % relative humidity and cyclic environments for 552 h and the surface finish was evaluated using visual and wave-scan distinctness of image (DOI) techniques. It was found that the laminate surface finish was dependent on the amount of moisture in the aging test. Minor surface waviness occurred on the laminates exposed to the cyclic test, whereas, surface waviness, print through and DOI values were all significantly higher as the laminates absorbed larger quantities of moisture from the hygrothermal and hydrothermal tests. The water immersion test, which was the most detrimental to the surface finish of the painted laminates, produced dense blistering on the autoclave manufactured laminate surface whereas the out-of-autoclave laminate surface produced only a few. It was found that the out-of-autoclave laminate had high substrate surface roughness which resulted in improved paint adhesion and, therefore, prevented the formation of surface blistering with aging. © 2012 Springer Science+Business Media Dordrecht.

Assessment of public attitudes towards sex offenders in an Australian population

Public attitudes towards sex offenders are believed to play a key role in the development of legislation and public policy designed to manage the risks posed by known sex offenders who live in the community. There have, however, been few previous attempts to validate methods by which public attitudes can be measured. The current study aims to address this issue by establishing the factor structure of the Community Attitudes Towards Sex Offenders (CATSO) scale with an Australian community sample and examine the extent to which demographic variables and support for sex offender management policies influence these attitudes. A sample of 552 participants recruited through online social media sites completed the CATSO as well as a number of items developed by the researchers designed to assess individuals’ support for specific sex offender policies. Results of an exploratory factor analysis suggested the presence of four distinct factors which were labelled ‘social tendencies’, ‘treatment and punishment’, ‘crime characteristics’ and ‘sexual behaviour’. Individuals with higher levels of educational attainment rated sex offenders less negatively than those with lower educational attainment, while those who reported being supportive of community notification reported more negative attitudes towards sex offenders.

Sex as a determinant of relapse incidence and progressive course of multiple sclerosis

The aim of this work was to evaluate sex differences in the incidence of multiple sclerosis relapses; assess the relationship between sex and primary progressive disease course; and compare effects of age and disease duration on relapse incidence. Annualized relapse rates were calculated using the MSBase registry. Patients with incomplete data or <1 year of follow-up were excluded. Patients with primary progressive multiple sclerosis were only included in the sex ratio analysis. Relapse incidences over 40 years of multiple sclerosis or 70 years of age were compared between females and males with Andersen-Gill and Tweedie models. Female-to-male ratios stratified by annual relapse count were evaluated across disease duration and patient age and compared between relapse-onset and primary progressive multiple sclerosis. The study cohort consisted of 11 570 eligible patients with relapse-onset and 881 patients with primary progressive multiple sclerosis. Among the relapse-onset patients (82 552 patient-years), 48 362 relapses were recorded. Relapse frequency was 17.7% higher in females compared with males. Within the initial 5 years, the female-to-male ratio increased from 2.3:1 to 3.3:1 in patients with 0 versus ≥4 relapses per year, respectively. The magnitude of this sex effect increased at longer disease duration and older age (P < 10−12). However, the female-to-male ratio in patients with relapse-onset multiple sclerosis and zero relapses in any given year was double that of the patients with primary progressive multiple sclerosis. Patient age was a more important determinant of decline in relapse incidence than disease duration (P < 10−12). Females are predisposed to higher relapse activity than males. However, this difference does not explain the markedly lower female-to-male sex ratio in primary progressive multiple sclerosis. Decline in relapse activity over time is more closely related to patient age than disease duration.

Gender differences in adolescent depression: Differential female susceptibility to stressors affecting family functioning

Objective: The aim of this study was to examine associations between family-based stressors and depressive symptoms in adolescents.

Method: Participants were 10-14 year olds who participated in a large Australian population study (n=6,552). Depressive symptoms and pubertal development were assessed using the self-report Short Mood and Feelings Questionnaire and the Pubertal Development Scale. Three indicators of stress exposure were examined-low emotional closeness to parents, residential and school transitions, and family conflict. The effect of gender, stress exposure and the interaction of gender and stress exposure on depressive symptoms was tested using multivariate logistic regression.

Results: High family conflict, residential instability and low emotional closeness with parents were independently associated with adolescent depressive symptoms. There was a significant gender by emotional closeness interaction; females reporting low emotional closeness to their parents were 2.3 times more likely to report high depressive symptoms than females reporting high emotional connections with parents.

Conclusions: Female adolescents may be more susceptible to particular types of stresses and particularly the quality of the parent-child relationship.

Association between participation in outpatient cardiac rehabilitation and self-reported receipt of lifestyle advice from a healthcare provider: results of a population-based cross-sectional survey

We test the hypothesis that the odds of self-reported receipt of lifestyle advice from a health care provider will be lower among outpatient cardiac rehabilitation (OCR) nonattendees and nonreferred patients compared to OCR attendees. Logistic regression was used to analyse cross-sectional data provided by 65% (4971/7678) of patients aged 20 to 84 years discharged from public hospitals with a diagnosis indicating eligibility for OCR between 2002 and 2007. Among respondents, 71% (3518) and 55% (2724) recalled advice regarding physical activity and diet, respectively, while 88% (592/674) of smokers recalled quit advice. OCR attendance was low: 36% (1764) of respondents reported attending OCR, 11% (552) did not attend following referral, and 45% (2217) did not recall being invited. The odds of recalling advice regarding physical activity and diet were significantly lower among OCR nonattendees compared to attendees (OR 0.34, 95% CI 0.21, 0.56 and OR 0.33, 95% CI 0.25, 0.44, resp.) and among nonreferred respondents compared to OCR attendees (OR 0.10, 95% CI 0.07, 0.15 and OR 0.17, 95% CI 0.14, 0.22, resp.). Patients hospitalised for coronary heart disease should be referred to OCR or a suitable alternative to improve recall of lifestyle advice that will reduce the risk of further coronary events.