Research news in brief

Years in full-time education associated with increased myopia

Researchers from the Australian National University (ANU), the University of Technology Sydney and the University of Bristol in the UK have found that spending more years in full-time education is associated with a greater risk of developing myopia. The study, published by The BMJ, found “strong evidence” that more time spent in education is a risk factor for myopia, and that the findings “have important implications for educational practices”. Currently, 30–50% of adults in the US and Europe have myopia, with levels of 80–90% reported in school leavers in some East Asian countries. Based on existing trends, the number of people affected by myopia worldwide is expected to increase from 1.4 billion to 5 billion by 2050, affecting about half of the world’s population. Almost 10% of these people (around 9 million) will have high myopia, which carries a greater risk of blindness. Using Mendelian randomisation, the researchers analysed 44 genetic variants associated with myopia and 69 genetic variants associated with higher levels of education for 67 798 men and women aged 40–69 years from the UK Biobank database. After taking account of potentially influential factors, the analyses suggested that every additional year of education was associated with more myopia (a refractive error of −0.27 dioptres a year). To put this into context, a university graduate from the UK with 17 years of education would, on average, be at least −1 dioptre more myopic than someone who left school at 16 years of age (with 12 years of education). This level of myopia would mean needing glasses for driving. By contrast, there was little evidence to suggest that myopia led people to remain in education for longer. In a linked editorial, Professor Ian Morgan at the ANU and colleagues wrote that the evidence suggested that it was not only genes but environmental and social factors that may have major effects on myopia. They pointed to East Asia, where early intense educational pressures combined with little time for play outdoors has led to almost 50% of children having myopia by the end of primary school, compared with less than 10% in a study of British children.

Tonsil, adenoid removal associated with long term respiratory risks

Researchers from the University of Melbourne have found that removing tonsils and adenoids in childhood increases the long term risk of respiratory, allergic and infectious diseases. In a study published in JAMA Otolaryngology Head and Neck Surgery, the research team analysed a dataset from Denmark of 1 189 061 children born between 1979 and 1999, covering tonsils or adenoids removed within a child’s first 9 years, and risk of disease up to 30 years of age. They found that 17 460 had adenoidectomies, 11 830 tonsillectomy and 31 377 had adenotonsillectomies, where both tonsils and adenoids removed. The children were otherwise healthy. They found that tonsillectomy was associated with an almost tripled relative risk for diseases of the upper respiratory tract. These included asthma, influenza, pneumonia and chronic obstructive pulmonary disease (COPD). The absolute risk (which takes into account how common these diseases are in the community) was also substantially increased at 18.61%. Adenoidectomy was found to be linked with a more than doubled relative risk of COPD and a nearly doubled relative risk of upper respiratory tract diseases and conjunctivitis. The absolute risk was also almost doubled for upper respiratory diseases but corresponded to a small increase for COPD, as this is a rarer condition in the community generally. Other results included: adenoidectomy was associated with a significantly reduced risk for sleep disorders and all surgeries were associated with significantly reduced risk for tonsillitis and chronic tonsillitis, as these organs were now removed; however, there was no change in abnormal breathing up to the age of 30 year for any surgery and no change in sinusitis after tonsillectomy or adenoidectomy; after adenotonsillectomy, the relative risk for those who had the operation was found to increase four- or five-fold for otitis media (inflammation of the middle ear) and sinusitis also showed a significant increase.

New F1 “halo” head protection may compromise steering

The head protection “halo” system mandated in Formula One racing may affect the drivers’ head position and motion, potentially compromising steering accuracy, according to a new simulation test led by Curtin University researchers. The case study, published in the journal BMJ Case Reports, examined the use of the halo frontal cockpit protection system – a titanium arc fitted to the open cockpit of a racing car – in a 70-year-old amateur racing driver with more than 10 years’ driving experience at the national level. The halo system was mandated by the motor sports’ governing body, the Fédération Internationale de l’Automobile for the 2018 Formula One season, following the death of French Formula One driver Jules Bianchi after a crash at the 2014 Japanese Grand Prix. In the study, muscle movement, fatigue and steering were measured using special sensors, electrodes (electromyography), and GPS trackers when the car was equipped with a halo, and when it wasn’t, during two warm-up laps and 10 “flying” laps. Analysis of the data indicated that muscle workload differed when the halo was fitted to the car, suggesting that the position of the driver’s head was affected. The authors acknowledge that the data are not complete, but those available suggest that that compared with a neutral position, the altered position might mean that the ability to stabilise the head and neck is reduced and may lead to a higher risk of neck injury and whiplash. Muscle fatigue was also uneven, suggesting that the driver’s head movement was also affected when the halo was fitted to the cockpit. This again might boost the risk of neck injury, say the authors. Lead author Dr Simon Rosalie said, “This case study suggests the halo system affects the head position and movement for drivers, which may [have an impact on] their navigation and the accuracy of steering.” He said the research indicated there may be a need for training and ergonomic adjustment to compensate for the impact on head position and movement.

What’s online first at the MJA

11 June Research: A nurse-led model at public academic hospitals maintains high adherence to colorectal cancer surveillance guidelines
Symonds et al; doi: 10.5694/mja17.00823
Nurse coordinators can help ensure adherence to guideline surveillance recommendations, reducing endoscopy workloads … OPEN ACCESS permanently.

11 June Podcast with Professor Erin Symonds, senior research scientist at the Flinders Centre for Innovation in Cancer … OPEN ACCESS permanently.

11 June Research letter: Out-of-pocket medical expenses for Queenslanders with a major cancer
Gordon et al; doi: 10.5694/mja17.00815
Lower medical fees and greater transparency would reduce the burden for people with cancer … OPEN ACCESS permanently.

11 June Podcast with Associate Professor Louisa Gordon, health economist at QIMR Berghofer Medical Research Institute … OPEN ACCESS permanently.

11 June Research letter: Information in referrals to public outpatient specialist clinics for back pain: audit results and consensus recommendations
Ross et al; doi: 10.5694/mja17.00813
The focus should be on eliciting a thorough history and examining the patient for red flags … OPEN ACCESS permanently.

11 June Podcast with Dr John Moi, consultant rheumatologist at Royal Melbourne Hospital … OPEN ACCESS permanently.

To find a doctor, or a job, to use GP Desktop and Doctors Health, book and track your CPD, and buy textbooks and guidelines, visit doctorportal.