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.

Little is known about the dose–response relationship between recreational arts engagement (for enjoyment, entertainment or as a hobby, rather than therapy) and mental well-being in the general population. The quantification of this relationship is of value to: (1) health professionals, clinicians and researchers interested in utilising the arts as a method for improving mental health; (2) to health promoters and policy makers in the development of population based health messages, policy and practice; and (3) to members of the general public in maintaining or improving their own well-being. As guided by theories of social epidemiology and the biopsychosocial model of health, the first aim of this study was to determine if there was a relationship between arts engagement (hours per year) and mental well-being in the general population. If an association was demonstrated, the second aim was to quantify this relationship. A random sample of 702 Western Australian adults aged 18+ years (response rate = 71 %) were invited to take part in a telephone survey. The survey took 15 min to complete and included questions about arts engagement, mental well-being, demographics and potential confounders/effect modifiers. The dependent variable was subjective mental well-being (Warwick-Edinburgh Mental Well-being Scale, WEMWBS). The independent variable was hours engaged in the arts in the last 12 months. Respondent engagement in the arts ranged from zero to 1572 hours/year (mean = 100.8 hours/year, SD = 206.0). The prevalence of engagement was 83 %. The average WEMWBS score was 53 (SD = 7.4). After adjustment for demographics (i.e. sex, age group, location, income, education, marital status, children), general health, sports engagement, religious activities and holidays, respondents with high levels of arts engagement (100 or more hours/year, WEMWBS score = 55) had significantly better mental well-being than those with none (0 hours/year, WEMWBS score = 53), low (0.1–22.9 hours/year, WEMWBS score = 52) and medium (23–99.9 hours/year, WEMWBS score = 53) levels of engagement (p = 0.003). Respondents with none, low and medium arts engagement had similar WEMWBS scores (p = 0.358). The relationship between arts engagement and WEMWBS was nonlinear with evidence of a minimum threshold at 100 or more hours/year (p = 0.0006). Evidence of an arts-mental health relationship was found in this study. Those who engaged in 100 or more hours/year of arts engagement (i.e. two or more hours/week) reported significantly better mental well-being than other levels of engagement. The suitability of the arts as a population based strategy to influence the mental well-being of the general population should be investigated further.

Background: Antimicrobial resistance is increasing globally, largely due to high rates of antibiotic use and misuse. Factors that influence frequent antibiotic use in children are poorly understood. Objectives: This study describes rates of antibiotic use in Australian children and investigates parental factors including knowledge, attitudes and behaviours that influence antibiotic use. Methods: An online questionnaire relating to antibiotic use was administered as part of the Royal Children’s Hospital National Child Health Poll to a randomly recruited nationwide sample of parents or guardians of children aged 0–17 years in Australia. Data on antibiotic use in children and parental knowledge of appropriate indications for antibiotics and behaviours were collected. Standard binary logistic regression was used to assess associations between parent demographics and behaviour with antibiotic administration. Results: The survey was completed by 2157 parents (64% completion rate), of which 1131 (52%) reported having given oral antibiotics to one or more of their children in the preceding 12 months. Of the 3971 children represented overall, 1719 (43%) had received at least one course of antibiotics. The average number of courses per child was 0.86 overall and 1.96 courses per child among those with reported antibiotic use. Notably, 194/1131 (17%) parents reported giving antibiotics to their child without a prescription. Poor parental knowledge of antibiotic indications was associated with antibiotic use. Conclusions: Reducing excessive use of antibiotics in children is necessary in the global strategy for preventing antimicrobial resistance. This study identified areas for public health interventions to educate parents and increase regulation of access to antibiotics.

Background: As of mid-2021, Australia’s only nationwide coronavirus disease 2019 (COVID-19) epidemic occurred in the first 6 months of the pandemic. Subsequently, there has been limited transmission in most states and territories. Understanding community spread during the first wave was hampered by initial limitations on testing and surveillance. To characterize the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibody seroprevalence generated during this time, we undertook Australia’s largest national SARS-CoV-2 serosurvey. Methods: Between June 19 and August 6, 2020, residual specimens were sampled from people undergoing general pathology testing (all ages), women attending antenatal screening (20–39 years), and blood donors (20–69 years) based on the Australian population’s age and geographic distributions. Specimens were tested by Wantai total SARS-CoV-2-antibody assay. Seroprevalence estimates adjusted for test performance were produced. The SARS-CoV-2 antibody-positive specimens were characterized with microneutralization assays. Results: Of 11 317 specimens (5132 general pathology; 2972 antenatal; 3213 blood-donors), 71 were positive for SARS-CoV-2-specific antibodies. Seroprevalence estimates were 0.47% (95% credible interval [CrI], 0.04%–0.89%), 0.25% (CrI, 0.03%–0.54%), and 0.23% (CrI, 0.04%–0.54%), respectively. No seropositive specimens had neutralizing antibodies. Conclusions: Australia’s seroprevalence was extremely low (<0.5%) after the only national COVID-19 wave thus far. These data and the subsequent limited community transmission highlight the population’s naivety to SARS-CoV-2 and the urgency of increasing vaccine-derived protection.