Research news in brief

One in 20 Australian adolescents has a food allergy

Approximately one in 20 Australian adolescents aged between 10 and 14 years has a food allergy, according to research from the Murdoch Childrens Research Institute (MCRI), published in the Journal of Allergy and Clinical Immunology. The results of the study, one of the few population-based studies in the world to examine the frequency of food allergy in early adolescence using the gold standard of oral food challenge, indicated that the prevalence of food allergy is around 5% in early adolescence. The SchoolNuts study was undertaken by the Australian Centre of Food and Allergy Research, based at the MCRI. Schools were randomly selected from greater metropolitan Melbourne, Australia, and students aged 10–14 years, and their parents, were asked to complete a questionnaire regarding the adolescent’s food allergy or food-related reactions. Of 20 965 eligible students, 9816 students (46.8 % participation) had parent and student questionnaires completed, 5016 had a complete parent response and underwent clinic evaluation, and an additional 4800 students had questionnaires only. Clinic evaluation consisted of skin prick tests and food challenge where eligible. The skin test covered 15 food allergens – egg white, cow’s milk, soy, peanut, cashew, almond, hazelnut, walnut, pistachio, macadamia, pecan, Brazil nut, pine nut, sesame and shellfish. A food challenge was undertaken if students were suspected of having a current food allergy from the response to the questionnaire, and further information was collected by phone and skin prick test results. Peanut and tree nut were the most common allergies, with each affecting 2–3% of adolescents. Cashews (1.6%) had the highest prevalence of the tree nuts, and egg (0.5%) had the highest reaction among the other (non-nut) foods. The authors acknowledged the likelihood of some participation selection bias which may have slightly affected the results.

Suicide may be contagious in United States army units

US research published in JAMA Psychiatry explored the question of whether a previous suicide attempt in a soldier’s US army unit increased the risk of other suicide attempts. The researchers, from the Uniformed Services University of the Health Sciences, used administrative data from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS) and identified records for all active-duty, regular US army, enlisted soldiers who attempted suicide from 2004 through 2009. There were 9512 enlisted soldiers in the final sample who attempted suicide. According to the results, soldiers were more likely to attempt suicide if one or more suicide attempts had occurred in their unit during the past year, and those odds increased as the number of suicide attempts in a unit increased. Also, soldiers in a unit with five or more suicide attempts in the past year had more than twice the odds of suicide attempt than soldiers in a unit with no previous suicide attempts. The authors discussed that unit characteristics that persist over time, including leadership quality, extent of social support and cohesion, and presence of bullying, may influence unit culture and affect the likelihood of and responses to unit suicide attempts. The study acknowledged limitations, including that data were subject to diagnostic or coding errors. In addition, the data focus on the 2004 through 2009 period and the findings may not be generalisable to earlier and later periods of the Iraq and Afghanistan wars or to other US military conflicts. “Early unit-based postvention consisting of coordinated efforts to provide behavioral, psychosocial, spiritual and public health support after suicide attempts may be an essential tool in promoting recovery and suicide prevention in service members,” the article’s authors concluded.

Rise in vaping linked to rise in smokers quitting

Research published in The BMJ shows that the recent rise in e-cigarette use among US adult smokers is associated with a significant increase in smoking cessation. A team of researchers at the University of California based their findings on five population surveys dating from 2001 to 2015. E-cigarette users were identified from the most recent survey (2014–15) and smoking cessation rates were obtained from people who reported smoking cigarettes 12 months before the survey. Smoking cessation rates from the 2014–15 survey were compared with four earlier surveys. It was known that e-cigarette use had increased dramatically from around 1.4% of smokers in 2010, to between 15% and 30% in 2014, thus a comparison between the 2010–11 and 2014–15 surveys was thought to provide the best chance yet to examine the effect of e-cigarettes on the overall smoking cessation rate. Of 161 054 respondents to the 2014–15 survey, 22 548 were current smokers and 2136 were recent quitters. The overall population quit rate for 2014–15 (5.6%) was significantly higher than that for 2010–11 (4.5%), and higher than the rates for all other survey years. The 1.1 percentage point increase in cessation rate represents approximately 350 000 additional US smokers who quit smoking. Of the 2014–15 sample, 38.2% of current smokers and 49.3% of recent quitters had tried e-cigarettes. The results also show that e-cigarette users were more likely than non-users to make a quit attempt (65% v 40%) and more likely to succeed in quitting for at least 3 months (8.2% v 4.8%). The main strength of the study is the use of the largest representative sample of e-cigarette users among the US population, while limitations included the nature of the survey questions, which prevented detailed analysis of the quitting process, and lack of information on the type of e-cigarette product used. The researchers noted: “Other interventions that occurred concurrently, such as a national campaign showing evocative ads that highlight the serious health consequences of tobacco use, most likely played a role in increasing the cessation rate … But this analysis presents a strong case that e-cigarette use also played an important role. These findings need to be weighed carefully in regulatory policy making and in the planning of tobacco control interventions”.

High rates of antibiotic prescriptions in Australian infants

Half of Australian infants are treated with antibiotics during their first year of life, according to research from the MCRI, published in the Journal of Paediatrics and Child Health. The study, which used data from the Barwon Infant Study, found that at least 20% of prescriptions were for what the parents thought were viral infections. The researchers found that 50% of the babies had at least one antibiotic prescription in the first year of life – much higher than almost all comparable industrialised countries. One in eight infants received three or more antibiotic prescriptions. The antibiotic prescription rate is almost 150% higher than in the United Kingdom, and almost 500% higher than in Switzerland. Children with siblings were more likely to be prescribed antibiotics, possibly due to the sharing of germs. Antibiotics were also commonly prescribed for ear infections, where antibiotics are generally ineffective and can usually be avoided. Compared with data from a study published in 2012, Australia has one of the highest antibiotic prescription rates worldwide and these rates have increased by 230% in the past decade.

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