School-age outcomes among IVF-conceived children: A population-wide cohort study.

BACKGROUND: In vitro fertilisation (IVF) is a common mode of conception. Understanding the long-term implications for these children is important. The aim of this study was to determine the causal effect of IVF conception on primary school-age childhood developmental and educational outcomes, compared with outcomes following spontaneous conception. METHODS AND FINDINGS: Causal inference methods were used to analyse observational data in a way that emulates a target randomised clinical trial. The study cohort comprised statewide linked maternal and childhood administrative data. Participants included singleton infants conceived spontaneously or via IVF, born in Victoria, Australia between 2005 and 2014 and who had school-age developmental and educational outcomes assessed. The exposure examined was conception via IVF, with spontaneous conception the control condition. Two outcome measures were assessed. The first, childhood developmental vulnerability at school entry (age 4 to 6), was assessed using the Australian Early Developmental Census (AEDC) (n = 173,200) and defined as scoring <10th percentile in ≥2/5 developmental domains (physical health and wellbeing, social competence, emotional maturity, language and cognitive skills, communication skills, and general knowledge). The second, educational outcome at age 7 to 9, was assessed using National Assessment Program-Literacy and Numeracy (NAPLAN) data (n = 342,311) and defined by overall z-score across 5 domains (grammar and punctuation, reading, writing, spelling, and numeracy). Inverse probability weighting with regression adjustment was used to estimate population average causal effects. The study included 412,713 children across the 2 outcome cohorts. Linked records were available for 4,697 IVF-conceived cases and 168,503 controls for AEDC, and 8,976 cases and 333,335 controls for NAPLAN. There was no causal effect of IVF-conception on the risk of developmental vulnerability at school-entry compared with spontaneously conceived children (AEDC metrics), with an adjusted risk difference of -0.3% (95% CI -3.7% to 3.1%) and an adjusted risk ratio of 0.97 (95% CI 0.77 to 1.25). At age 7 to 9 years, there was no causal effect of IVF-conception on the NAPLAN overall z-score, with an adjusted mean difference of 0.030 (95% CI -0.018 to 0.077) between IVF- and spontaneously conceived children. The models were adjusted for sex at birth, age at assessment, language background other than English, socioeconomic status, maternal age, parity, and education. Study limitations included the use of observational data, the potential for unmeasured confounding, the presence of missing data, and the necessary restriction of the cohort to children attending school. CONCLUSIONS: In this analysis, under the given causal assumptions, the school-age developmental and educational outcomes for children conceived by IVF are equivalent to those of spontaneously conceived children. These findings provide important reassurance for current and prospective parents and for clinicians.

Smoking Inequality Trends by Disability and Income in Australia, 2001 to 2020.

BACKGROUND: While policies to reduce smoking in many countries have been successful, disadvantaged groups (such as low-income groups) have only seen minor gains. People with disability are one such disadvantaged group and are more likely to smoke. However, evidence is limited on trends and inequalities in smoking for disabled people and on whether those also on low incomes are more likely to smoke. METHODS: We use annual data from 2001 to 2020 of the Household Income and Labour Dynamics in Australia survey. We use a Bayesian model to estimate smoking prevalence trends and inequalities for people with disability (2020, n = 1,370) and without disability (2020, n = 6,229) across the whole population and within income tertiles. To avoid reverse causation (smoking causing disability), we focus on younger people (15-44 years). RESULTS: Absolute reductions (per 100 people, [95% credible intervals]) in smoking were similar for people with (-13 [-16, -11]) and without disability (-15 [-16, -14]), with stable absolute but increasing relative inequalities. In the low-income group, absolute reductions in smoking prevalence for people with disability (-10 [-14, -6]) were smaller than in people without disability (-14 [-15, -12]), resulting in moderate evidence for increasing absolute inequalities (4 [0, 8]) and strong evidence for increasing relative inequalities. In high-income groups, disability-related absolute inequalities narrowed (-6 [-10, -3]), and relative inequalities were stable. CONCLUSIONS: Disabled people in Australia, especially those on low incomes, show signs of being left behind in efforts to reduce smoking.

The natural history of peanut and egg allergy in children up to age 6 years in the HealthNuts population-based longitudinal study.

BACKGROUND: Prospectively collected data on the natural history of food allergy are lacking. OBJECTIVE: We examined the natural history of egg and peanut allergy in children from age 1 to 6 years and assessed whether a skin prick test (SPT) result or other clinical factors at diagnosis are associated with the persistence or resolution of food allergy in early childhood. METHODS: The HealthNuts cohort consists of 5276 children who were recruited at age 1 year and have been followed prospectively. Children with food allergy at age 1 year (peanut [n = 156] or raw egg [n = 471] allergy ) and children who developed new sensitizations or food reactions after age 1 year were assessed for food sensitization and allergy (confirmed by oral food challenge when indicated) at the 6-year follow-up. RESULTS: New-onset food allergy developed by age 6 years was more common for peanut (0.7% [95% CI = 0.5%-1.1%]) than egg (0.09% [95% CI = 0.03%-0.3%]). Egg allergy resolved more commonly (89% [95% CI = 85%-92%]) than peanut allergy (29% [95% CI = 22%-38%]) by age 6 years. The overall weighted prevalence of peanut allergy at age 6 years was 3.1% (95% CI = 2.6-3.7%) and that of egg allergy was 1.2% (95% = CI 0.9%-1.6%). The factors at age 1 year associated with persistence of peanut allergy were peanut SPT result of 8 mm or larger (odds ratio [OR] = 2.35 [95% CI 1.08-5.12]), sensitization to tree nuts (adjusted OR [aOR] = 2.51 [95% CI = 1.00-6.35]), and early-onset severe eczema (aOR = 3.23, [95% CI 1.17-8.88]). Factors at age 1 associated with persistence of egg allergy at age 6 were egg SPT result of 4 mm or larger (OR = 2.98 [95% CI 1.35-6.36]), other (peanut and/or sesame) food sensitizations (aOR = 2.80 [95% CI = 1.11-7.03]), baked egg allergy (aOR = 7.41 [95% CI = 2.16-25.3]), and early-onset severe eczema (aOR = 3.77 [95% CI = 1.35-10.52]). CONCLUSION: Most egg allergy and nearly one-third of peanut allergy resolves naturally by age 6 years. The prevalence of peanut allergy at age 6 years was similar to that observed at age 1 year, largely owing to new-onset food peanut allergy after age 1 year. Infants with early-onset eczema, larger SPT wheals, or multiple food sensitizations and/or allergies were less likely to acquire tolerance to either peanut or egg.

Violation of research integrity principles occurs more often than we think.

The science community generally believes that the violation of research integrity is rare. Built upon this belief, the scientific system makes little effort to examine the trustworthiness of research. Research misconduct refers to an intentional violation of research integrity principles, which has an extensive and far-reaching impact on the trustworthiness and reputation of science. Emerging evidence has suggested that research misconduct is far more common than we normally perceive. Far more problematic papers should be retracted than are being retracted because of poor actions when confronting research misconduct. Research misconduct is usually driven by incentives in the form of pursuing publications for researchers' career needs and is further facilitated by poor research governance. The current strategy that tackles potential research misconduct focuses on protecting the reputation of authors and their institutions but neglects the interests of patients, clinicians and honest researchers. Removing improper incentives, training researchers and imposing better governance are vital to reducing research misconduct. Awareness of the possibility of misconduct and formalized procedures that scrutinize study trustworthiness are important during peer review and in systematic reviews.

Traditionalism vs egalitarianism: Is there an association between gender attitudes and mental health?

OBJECTIVE: This study sought to assess the extent to which gender attitudes are associated with mental health among Australian men and women. METHODS: This study used a sample of 26,188 individuals drawn from five waves of the Household, Income and Labour Dynamics in Australia Survey. Gender attitudes were classified into three groups (traditional, moderate-egalitarian and egalitarian), and were constructed from six items. Mental health was measured using the Mental Health Inventory (MHI-5). We calculated the magnitude of associations between gender attitudes and mental health, stratified by gender, and adjusted for potential confounding. RESULTS: Compared to men with egalitarian attitudes, poorer mental health was observed among men with moderate-egalitarian (-1.16, 95% confidence interval = [-1.84, -0.49]) and traditional gender attitudes (-2.57, 95% confidence interval = [-3.33, -1.81]). Among women, poorer mental health was observed among those with moderate-egalitarian (-0.78, 95% confidence interval = [-1.34, -0.22]) and traditional attitudes (-1.91, 95% confidence interval = [-2.55, -1.26]) compared to those with egalitarian attitudes. CONCLUSIONS: For both men and women, egalitarian gender attitudes were associated with better mental health.

Association Between Earlier Introduction of Peanut and Prevalence of Peanut Allergy in Infants in Australia.

Importance: Randomized clinical trials showed that earlier peanut introduction can prevent peanut allergy in select high-risk populations. This led to changes in infant feeding guidelines in 2016 to recommend early peanut introduction for all infants to reduce the risk of peanut allergy. Objective: To measure the change in population prevalence of peanut allergy in infants after the introduction of these new guidelines and evaluate the association between early peanut introduction and peanut allergy. Design: Two population-based cross-sectional samples of infants aged 12 months were recruited 10 years apart using the same sampling frame and methods to allow comparison of changes over time. Infants were recruited from immunization centers around Melbourne, Australia. Infants attending their 12-month immunization visit were eligible to participate (eligible age range, 11-15 months), regardless of history of peanut exposure or allergy history. Exposures: Questionnaires collected data on demographics, food allergy risk factors, peanut introduction, and reactions. Main Outcome and Measures: All infants underwent skin prick tests to peanut and those with positive results underwent oral food challenges. Prevalence estimates were standardized to account for changes in population demographics over time. Results: This study included 7209 infants (1933 in 2018-2019 and 5276 in 2007-2011). Of the participants in the older vs more recent cohort, 51.8% vs 50.8% were male; median (IQR) ages were 12.5 (12.2-13.0) months vs 12.4 (12.2-12.9) months. There was an increase in infants of East Asian ancestry over time (16.5% in 2018-2019 vs 10.5% in 2007-2011), which is a food allergy risk factor. After standardizing for infant ancestry and other demographics changes, peanut allergy prevalence was 2.6% (95% CI, 1.8%-3.4%) in 2018-2019, compared with 3.1% in 2007-2011 (difference, -0.5% [95% CI, -1.4% to 0.4%]; P = .26). Earlier age of peanut introduction was significantly associated with a lower risk of peanut allergy among infants of Australian ancestry in 2018-2019 (age 12 months compared with age 6 months or younger: adjusted odds ratio, 0.08 [05% CI, 0.02-0.36]; age 12 months compared with 7 to less than 10 months: adjusted odds ratio, 0.09 [95% CI, 0.02-0.53]), but not significant among infants of East Asian ancestry (P for interaction = .002). Conclusions and Relevance: In cross-sectional analyses, introduction of a guideline recommending early peanut introduction in Australia was not associated with a statistically significant lower or higher prevalence of peanut allergy across the population.

Adiposity and estrogen receptor-positive, postmenopausal breast cancer risk: Quantification of the mediating effects of fasting insulin and free estradiol.

Adiposity increases estrogen receptor (ER)-positive postmenopausal breast cancer risk. While mechanisms underlying this relationship are uncertain, dysregulated sex-steroid hormone production and insulin signaling are likely pathways. Our aim was to quantify mediating effects of fasting insulin and free estradiol in the adiposity and ER-positive postmenopausal breast cancer association. We used data from a case-cohort study of sex hormones and insulin signaling nested within the Melbourne Collaborative Cohort Study. Eligible women, at baseline, were not diagnosed with cancer, were postmenopausal, did not use hormone therapy and had no history of diabetes or diabetes medication use. Women with ER-negative disease or breast cancer diagnosis within the first follow-up year were excluded. We analyzed the study as a cumulative sampling case-control study with 149 cases and 1,029 controls. Missing values for insulin and free estradiol were multiply imputed with chained equations. Interventional direct (IDE) and indirect (IIE) effects were estimated using regression-based multiple-mediator approach. For women with body mass index (BMI) >30 kg/m2 compared to women with BMI 18.5-25 kg/m2 , the risk ratio (RR) of breast cancer was 1.75 (95% confidence interval [CI] 1.05-2.91). The estimated IDE (RR) not through the mediators was 1.03 (95% CI 0.43-2.48). Percentage mediated effect through free estradiol was 72% (IIE-RR 1.56; 95% CI 1.11-2.19). There was no evidence for an indirect effect through insulin (IIE-RR 1.12; 95% CI 0.68-1.84; 28% mediated). Our results suggest that circulating free estradiol plays an important mediating role in the adiposity-breast cancer relationship but does not explain all of the association.

Childhood pneumonia, pleurisy and lung function: a cohort study from the first to sixth decade of life.

INTRODUCTION: Adult spirometry following community-acquired childhood pneumonia has variably been reported as showing obstructive or non-obstructive deficits. We analysed associations between doctor-diagnosed childhood pneumonia/pleurisy and more comprehensive lung function in a middle-aged general population cohort born in 1961. METHODS: Data were from the prospective population-based Tasmanian Longitudinal Health Study cohort. Analysed lung function was from ages 7 years (prebronchodilator spirometry only, n=7097), 45 years (postbronchodilator spirometry, carbon monoxide transfer factor and static lung volumes, n=1220) and 53 years (postbronchodilator spirometry and transfer factor, n=2485). Parent-recalled histories of doctor-diagnosed childhood pneumonia and/or pleurisy were recorded at age 7. Multivariable linear and logistic regression were used. RESULTS: At age 7, compared with no episodes, childhood pneumonia/pleurisy-ever was associated with reduced FEV1:FVC for only those with current asthma (beta-coefficient or change in z-score=-0.20 SD, 95% CI -0.38 to -0.02, p=0.028, p interaction=0.036). At age 45, for all participants, childhood pneumonia/pleurisy-ever was associated with a restrictive pattern: OR 3.02 (1.5 to 6.0), p=0.002 for spirometric restriction (FVC less than the lower limit of normal plus FEV1:FVC greater than the lower limit of normal); total lung capacity z-score -0.26 SD (95% CI -0.38 to -0.13), p<0.001; functional residual capacity -0.16 SD (-0.34 to -0.08), p=0.001; and residual volume -0.18 SD (-0.31 to -0.05), p=0.008. Reduced lung volumes were accompanied by increased carbon monoxide transfer coefficient at both time points (z-score +0.29 SD (0.11 to 0.49), p=0.001 and +0.17 SD (0.04 to 0.29), p=0.008, respectively). DISCUSSION: For this community-based population, doctor-diagnosed childhood pneumonia and/or pleurisy were associated with obstructed lung function at age 7 for children who had current asthma symptoms, but with evidence of 'smaller lungs' when in middle age.

Hierarchical Models for International Comparisons: Smoking, Disability, and Social Inequality in 21 European Countries.

BACKGROUND: International comparisons of social inequalities in health outcomes and behaviors are challenging. Due to the level of disaggregation often required, data can be sparse and methods to make adequately powered comparisons are lacking. We aimed to illustrate the value of a hierarchical Bayesian approach that partially pools country-level estimates, reducing the influence of sampling variation and increasing the stability of estimates. We also illustrate a new way of simultaneously displaying the uncertainty of both relative and absolute inequality estimates. METHODS: We used the 2014 European Social Survey to estimate smoking prevalence, absolute, and relative inequalities for men and women with and without disabilities in 21 European countries. We simultaneously display smoking prevalence for people without disabilities (x-axis), absolute (y-axis), and relative inequalities (contour lines), capturing the uncertainty of these estimates by plotting a 2-D normal approximation of the posterior distribution from the full probability (Bayesian) analysis. RESULTS: Our study confirms that across Europe smoking prevalence is generally higher for people with disabilities than for those without. Our model shifts more extreme prevalence estimates that are based on fewer observations, toward the European mean. CONCLUSIONS: We demonstrate the utility of partial pooling to make adequately powered estimates of inequality, allowing estimates from countries with smaller sample sizes to benefit from the increased precision of the European average. Including uncertainty on our inequality plot provides a useful tool for evaluating both the geographical patterns of variation in, and strength of evidence for, differences in social inequalities in health.

Patterns of tree nut sensitization and allergy in the first 6 years of life in a population-based cohort.

BACKGROUND: Longitudinal population-based data regarding tree nut allergy are limited. OBJECTIVES: We sought to determine the population prevalence of tree nut allergy at age 6 years and explore the relationship between egg and peanut allergy at age 1 year and development of tree nut allergy at age 6 years. METHODS: A population-based sample of 5276 children was recruited at age 1 year and followed up at age 6 years. At age 1 year, allergies to egg and peanut were determined by means of oral food challenge, and parents reported their child's history of reaction to tree nuts. Challenge-confirmed tree nut allergy was assessed at age 6 years. RESULTS: At age 1 year, the prevalence of parent-reported tree nut allergy was 0.1% (95% CI, 0.04% to 0.2%). Only 18.5% of infants had consumed tree nuts in the first year of life. At age 6 years, challenge-confirmed tree nut allergy prevalence was 3.3% (95% CI, 2.8% to 4.0%), with cashew the most common (2.7%; 95% CI, 2.2% to 3.3%). Of children with peanut allergy only at age 1 year, 27% (95% CI, 16.1% to 39.7%) had tree nut allergy at age 6 years compared with 14% (95% CI, 10.4% to 17.9%) of those with egg allergy only and 37% (95% CI, 27.2% to 47.4%) of those with both peanut and egg allergy. CONCLUSIONS: Tree nut allergy is uncommon in the first year of life, likely because of limited tree nut consumption. At age 6 years, tree nut allergy prevalence is similar to peanut allergy prevalence. More than a third of children with both peanut and egg allergy in infancy have tree nut allergy at age 6 years. Understanding how to prevent tree nut allergy should be an urgent priority for future research.

Earlier ingestion of peanut after changes to infant feeding guidelines: The EarlyNuts study.

BACKGROUND: Randomized controlled trials demonstrate that timely introduction of peanut to infants reduces the risk of peanut allergy. However, much debate remains regarding how to best achieve earlier peanut introduction at the population level. Our previous study in 2007-2011 (HealthNuts, n = 5300) indicated that few infants were consuming peanut in the first year. Australian infant feeding guidelines were updated in 2016 to recommend introducing peanut before 12 months for all infants. There were no data available on the subsequent effect on peanut introduction or peanut reactions. OBJECTIVE: We sought to assess the consequences of a nonscreening approach to allergenic food introduction in a population-based sample of infants in their first year of life. METHODS: EarlyNuts is a population-based, cross-sectional study of 12-month-old infants in Melbourne, Australia, recruited by using an identical sampling frame and methods to HealthNuts (72% response rate vs 73% response rate in HealthNuts). We report here on the first 860 participants recruited between November 2016 and October 2018. RESULTS: Most infants (88.6%; 95% CI, 86.1% to 90.7%) had introduced peanut by 12 months (median age, 6 months), an increase from 28.4% (95% CI, 27.2% to 29.7%) in the HealthNuts study. By 12 months, the majority of these (76.4%) had consumed peanut more than 4 times, and 28% were eating peanut more than once per week. Preliminary results on parent-reported reactions show that 4.0% of those consuming peanut by 12 months had possible IgE-mediated reactions. CONCLUSIONS: There has been a striking shift toward earlier peanut introduction, with a 3-fold increase in peanut introduction by age 1 year in 2018 compared with 2007-2011.

Occupational exposure to solvents and lung function decline: A population based study.

RATIONALE: While cross-sectional studies have shown associations between certain occupational exposures and lower levels of lung function, there was little evidence from population-based studies with repeated lung function measurements. OBJECTIVES: We aimed to investigate the associations between occupational exposures and longitudinal lung function decline in the population-based Tasmanian Longitudinal Health Study. METHODS: Lung function decline between ages 45 years and 50 years was assessed using data from 767 participants. Using lifetime work history calendars completed at age 45 years, exposures were assigned according to the ALOHA plus Job Exposure Matrix. Occupational exposures were defined as ever exposed and cumulative exposure -unit- years. We investigated effect modification by sex, smoking and asthma status. RESULTS: Compared with those without exposure, ever exposures to aromatic solvents and metals were associated with a greater decline in FEV1 (aromatic solvents 15.5 mL/year (95% CI -24.8 to 6.3); metals 11.3 mL/year (95% CI -21.9 to - 0.7)) and FVC (aromatic solvents 14.1 mL/year 95% CI -28.8 to - 0.7; metals 17.5 mL/year (95% CI -34.3 to - 0.8)). Cumulative exposure (unit years) to aromatic solvents was also associated with greater decline in FEV1 and FVC. Women had lower cumulative exposure years to aromatic solvents than men (mean (SD) 9.6 (15.5) vs 16.6 (14.6)), but greater lung function decline than men. We also found association between ever exposures to gases/fumes or mineral dust and greater decline in lung function. CONCLUSIONS: Exposures to aromatic solvents and metals were associated with greater lung function decline. The effect of aromatic solvents was strongest in women. Preventive strategies should be implemented to reduce these exposures in the workplace.

Randomised controlled trials evaluating endometrial scratching: assessment of methodological issues.

STUDY QUESTION: Do randomised controlled trials (RCTs) evaluating endometrial scratching suffer from methodological issues including insufficient trial registration, statistical errors or irreproducibility, randomisation errors or miscellaneous issues? SUMMARY ANSWER: The majority of RCTs investigating endometrial scratching have methodological issues. WHAT IS KNOWN ALREADY: A large number of small RCTs investigating the effectiveness of endometrial scratching prior to in vitro fertilisation (IVF) and intrauterine insemination (IUI)/intercourse have reported favourable findings. Subsequently, systematic reviews incorporating these RCTs yielded meta-analyses in favour of endometrial scratching. Endometrial scratching has been widely adopted by infertility specialists around the world. Recently, an international RCT including 1364 women reported no benefit from endometrial scratching before IVF. STUDY DESIGN, SIZE, DURATION: We evaluated several methodological issues of RCTs investigating the effectiveness of endometrial scratching prior to IVF and IUI/intercourse. We identified 25 RCTs for IVF and 12 RCTs for IUI/intercourse with full-text publication. PARTICIPANTS/MATERIALS, SETTING, METHODS: We assessed the RCTs on the following criteria: adequacy of trial registration, statistical issues (description of statistical methods and reproducibility of univariable statistical analysis), excessive similarity or difference in baseline characteristics that is not compatible with chance (Monte Carlo simulations and Kolmogorov-Smirnov test) and miscellaneous methodological issues. MAIN RESULTS AND THE ROLE OF CHANCE: Of 25 RCTs evaluating endometrial scratching prior to IVF, only eight (32%) had adequate trial registration. In total, 10 (40%) RCTs had issues regarding statistical methods. Nine (69%, 13 applicable) RCTs had at least one inconsistency between reported and reproduced univariable statistical analysis for categorical baseline/intermediate characteristics. Statistical results of at least one outcome were not reproducible in 14 (74%, 19 applicable) RCTs. Only two (8%) RCTs had none of the above issues. Suggested by the simulations, these RCTs did not significantly violate the null hypothesis that the baseline characteristics were the results of a properly conducted randomisation process (P = 0.4395).Of 12 IUI/intercourse RCTs, only 2 (17%) had adequate trial registration. In total, five (42%) studies had issues of statistical methods. Inconsistency between reported and reproduced univariable analysis for baseline/intermediate categorical variable(s) was found in four (57%, 7 applicable) RCTs. Statistical analysis was not reproducible for at least one outcome in eight (80%, 10 applicable) studies. All RCTs had at least one of the above issues. These RCTs were inconsistent with the null hypothesis that their baseline characteristics were the results of proper randomised allocation (P = 1.659*10-7). LIMITATIONS, REASONS FOR CAUTION: We were unable to assess RCTs which were not published as full-text papers. We could not analyse individual participant data to investigate possible reasons for statistical inconsistencies. The method to infer the likelihood of proper random sampling rests on assumptions including independent baseline characteristics, simple randomisation and no publication bias. WIDER IMPLICATIONS OF THE FINDINGS: The methodological issues common to RCTs evaluating endometrial scratching may have biased the results of the trials. Further development and validation of these novel methods may be helpful for the critical appraisal of RCTs. STUDY FUNDING/COMPETING INTEREST(S): No external funding was sought to support this work. B.W.M. is supported by a National Health Medical Research Council (NHMRC) Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for ObsEva, Merck and Guerbet. D.W. is supported by a grant from the Paracelsus Medical University Salzburg, Austria (PMU Research Fund-PMU FFF Number: L-18/02/006-WET) and by Drs Haackert Foundation, Germany. S.L. is an author of a trial included in this study, an author of an included systematic review and a Cochrane editor. All other authors have no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Egg allergen specific IgE diversity predicts resolution of egg allergy in the population cohort HealthNuts.

BACKGROUND: IgE-mediated egg allergy presents as one of the most common food allergies in children. Measurement of egg white specific IgE (sIgE) levels in serum or skin prick test has been shown to be a poor predictor of clinical allergy to raw egg white, and also to baked or cooked egg. Recent developments in component resolved diagnostic (CRD) technology have enabled us to improve the way in which we diagnose and predict peanut allergy by examining IgE specificity to individual peptides. OBJECTIVES: We aimed to investigate whether egg CRD could improve current methods to diagnose various egg allergy phenotypes as well as predict the development of tolerance to egg. METHODS: Using the HealthNuts cohort of food challenge-proven egg allergic and egg-sensitized and egg-tolerant, age-matched 12-month infants with longitudinal follow-up at 2 and 4 years (n = 451), we measured serum egg white, Gal d 1, 2, 3 and 5 sIgE using ImmunoCAP. RESULTS: Gal d 1 sensitization increased the risk of persistent egg allergy by 2.5-fold. The production of sIgE to all four egg allergens (Gal d 1, 2, 3 or 5) increased the risk of having persistent raw egg allergy fourfold (OR 4.19 (95% CI: 1.25-14.07). We did not find any improvements of using Gal d 1, 2, 3 or 5 to diagnose current egg allergy compared to egg white sIgE. CONCLUSION: Sensitization to multiple egg allergens Gal d 1, 2, 3 or 5 may be a prognostic marker that could be useful for patient management and identifying individuals at risk of developing persistent egg allergy.

Effect decomposition through multiple causally nonordered mediators in the presence of exposure-induced mediator-outcome confounding.

Avin et al (2005) showed that, in the presence of exposure-induced mediator-outcome confounding, decomposing the total causal effect (TCE) using standard conditional exchangeability assumptions is not possible even under a nonparametric structural equation model with all confounders observed. Subsequent research has investigated the assumptions required for such a decomposition to be identifiable and estimable from observed data. One approach was proposed by VanderWeele et al (2014). They decomposed the TCE under three different scenarios: (1) treating the mediator and the exposure-induced confounder as joint mediators; (2) generating path-specific effects albeit without distinguishing between multiple distinct paths through the exposure-induced confounder; and (3) using so-called randomised interventional analogues where sampling values from the distribution of the mediator within the levels of the exposure effectively marginalises over the exposure-induced confounder. In this paper, we extend their approach to the case where there are multiple mediators that do not influence each other directly but which are all influenced by an exposure-induced mediator-outcome confounder. We provide a motivating example and results from a simulation study based on from our work in dental epidemiology featuring the 1982 Pelotas Birth Cohort in Brazil.

Sustained adherence to a Mediterranean diet and physical activity on all-cause mortality in the Melbourne Collaborative Cohort Study: application of the g-formula.

BACKGROUND: Adherence to a traditional Mediterranean diet has been associated with lower mortality and cardiovascular disease risk. The relative importance of diet compared to other lifestyle factors and effects of dietary patterns over time remains unknown. METHODS: We used the parametric G-formula to account for time-dependent confounding, in order to assess the relative importance of diet compared to other lifestyle factors and effects of dietary patterns over time. We included healthy Melbourne Collaborative Cohort Study participants attending a visit during 1995-1999. Questionnaires assessed diet and physical activity at each of three study waves. Deaths were identified by linkage to national registries. We estimated mortality risk over approximately 14 years (1995-2011). RESULTS: Of 22,213 participants, 2163 (9.7%) died during 13.6 years median follow-up. Sustained high physical activity and adherence to a Mediterranean-style diet resulted in an estimated reduction in all-cause mortality of 1.82 per 100 people (95% confidence interval (CI): 0.03, 3.6). The population attributable fraction was 13% (95% CI: 4, 23%) for sustained high physical activity, 7% (95% CI: - 3, 17%) for sustained adherence to a Mediterranean-style diet and 18% (95% CI: 0, 36%) for their combination. CONCLUSIONS: A small reduction in mortality may be achieved by sustained elevated physical activity levels in healthy middle-aged adults, but there may be comparatively little gain from increasing adherence to a Mediterranean-style diet.

Prevalence of clinic-defined food allergy in early adolescence: The SchoolNuts study.

BACKGROUND: Rising rates of food-induced anaphylaxis have recently been shown in the adolescent age group, following earlier descriptions of a rise in children younger than 5 years. However, few population-based studies have examined the prevalence of food allergy in adolescence using objective measures such as oral food challenge (OFC). OBJECTIVE: We sought to determine the prevalence of food allergy among a population-based sample of 10- to 14-year-old adolescents using clinical evaluation including OFC to confirm the diagnosis. METHODS: Schools were randomly selected from greater metropolitan Melbourne, Australia. Students aged 10 to 14 years, and their parents, were asked to complete a questionnaire regarding the adolescent's food allergy or food-related reactions. Clinic evaluation, which consisted of skin prick tests and OFC where eligible, was undertaken if students were suspected to have current food allergy from parent response. Among 9816 students assessed, 5016 had complete parent response and clinic evaluation when eligible. An additional 4800 students had student questionnaires only. RESULTS: The prevalence of clinic-defined current food allergy based on history, sensitization data, and OFC results was 4.5% (95% CI, 3.9-5.1), with the most common food triggers being peanut, 2.7% (95% CI, 2.3-3.2), and tree nut, 2.3% (95% CI, 1.9-2.8). Among the additional group of 4800 adolescents who had only self-reported food allergy status available, the prevalence of self-reported current food allergy was 5.5% (95% CI, 4.9-6.2), with peanut, 2.8% (95% CI, 2.3-3.3), and tree nut, 2.3% (95% CI, 1.9-2.8), the most common. CONCLUSIONS: Approximately 1 in 20 10- to 14-year-old school students in Melbourne has current food allergy. This high prevalence suggests that the previously reported rise in food-induced anaphylaxis in this age group may reflect an increasing prevalence of food allergy rather than simply increased reporting of anaphylaxis.

Multilevel Regression and Poststratification: A Modeling Approach to Estimating Population Quantities From Highly Selected Survey Samples.

Investigators in large-scale population health studies face increasing difficulties in recruiting representative samples of participants. Nonparticipation, item nonresponse, and attrition, when follow-up is involved, often result in highly selected samples even in well-designed studies. We aimed to assess the potential value of multilevel regression and poststratification, a method previously used to successfully forecast US presidential election results, for addressing biases due to nonparticipation in the estimation of population descriptive quantities in large cohort studies. The investigation was performed as an extensive case study using baseline data (2013-2014) from a large national health survey of Australian males (Ten to Men: The Australian Longitudinal Study on Male Health). Analyses were performed in the open-source Bayesian computational package RStan. Results showed greater consistency and precision across population subsets of varying sizes when compared with estimates obtained using conventional survey sampling weights. Estimates for smaller population subsets exhibited a greater degree of shrinkage towards the national estimate. Multilevel regression and poststratification provides a promising analytical approach to addressing potential participation bias in the estimation of population descriptive quantities from large-scale health surveys and cohort studies.

Clinical penetrance in hereditary hemochromatosis: estimates of the cumulative incidence of severe liver disease among HFE C282Y homozygotes.

Iron overload (hemochromatosis) can cause serious, symptomatic disease that is preventable if detected early and managed appropriately. The leading cause of hemochromatosis in populations of predominantly European ancestry is homozygosity of the C282Y variant in the HFE gene. Screening of adults for iron overload or associated genotypes is controversial, largely because of a belief that severe phenotypes are uncommon, although cascade testing of first-degree relatives of patients is widely endorsed. We contend that severe liver disease (cirrhosis or hepatocellular cancer) is not at all uncommon among older males with hereditary hemochromatosis. Our review of the published data from a variety of empirical sources indicates that roughly 1 in 10 male HFE C282Y homozygotes is likely to develop severe liver disease during his lifetime unless iron overload is detected early and treated. New evidence from a randomized controlled trial of treatment allows for evidence-based management of presymptomatic patients. Although population screening for HFE C282Y homozygosity faces multiple barriers, a potentially effective strategy for increasing the early detection and prevention of clinical iron overload and severe disease is to include HFE C282Y homozygosity in lists of medically actionable gene variants when reporting the results of genome or exome sequencing.

Socioeconomic and Tobacco Mediation of Ethnic Inequalities in Mortality over Time: Repeated Census-mortality Cohort Studies, 1981 to 2011.

BACKGROUND: Racial/ethnic inequalities in mortality may be reducible by addressing socioeconomic factors and smoking. To our knowledge, this is the first study to estimate trends over multiple decades in (1) mediation of racial/ethnic inequalities in mortality (between Maori and Europeans in New Zealand) by socioeconomic factors, (2) additional mediation through smoking, and (3) inequalities had there never been smoking. METHODS: We estimated natural (1 and 2 above) and controlled mediation effects (3 above) in census-mortality cohorts for 1981-1984 (1.1 million people), 1996-1999 (1.5 million), and 2006-2011 (1.5 million) for 25- to 74-year-olds in New Zealand, using a weighting of regression predicted outcomes. RESULTS: Socioeconomic factors explained 46% of male inequalities in all three cohorts and made an increasing contribution over time among females from 30.4% (95% confidence interval = 18.1%, 42.7%) in 1981-1984 to 41.9% (36.0%, 48.0%). Including smoking with socioeconomic factors only modestly altered the percentage mediated for males, but more substantially increased it for females, for example, 7.7% (5.5%, 10.0%) in 2006-2011. A counterfactual scenario of having eradicated tobacco in the past (but unchanged socioeconomic distribution) lowered mortality for all sex-by-ethnic groups and resulted in a 12.2% (2.9%, 20.8%) and 21.2% (11.6%, 31.0%) reduction in the absolute mortality gap between Maori and Europeans in 2006-2011, for males and females, respectively. CONCLUSIONS: Our study predicts that, in this high-income country, reducing socioeconomic disparities between ethnic groups would greatly reduce ethnic inequalities in mortality over the long run. Eradicating tobacco would notably reduce ethnic inequalities in absolute but not relative mortality.