"Number of children with anorexia on the rise," reports The Guardian.
The headline is based on a study of records of eating disorders in children and young people in the UK and Ireland carried out in 2015. Child and adolescent psychiatrists reported 305 new cases of anorexia during an 8-month period, among children and young people with an average age of between 14 to 15 years. Overall, that translated to around 14 new cases of anorexia per 100,000 young people aged 8 to 17 each year.
The numbers of cases differed greatly by age and sex. Anorexia was more common among girls and those aged 12 to 16 than among boys or younger children. These findings would seem to confirm previous research that suggests anorexia is a particular problem in teenage girls.
The researchers found evidence to suggest more new cases of anorexia among children aged 8 to 12, compared with a decade earlier. While this is concerning, anorexia is still very uncommon among children this age.
The study only included children who had been assessed as new cases by child and adolescent psychiatrists during this period. This means the research would not pick up children with anorexia whose condition had gone unnoticed, who had not been referred for help, or who were being treated by GPs or other services.
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You might also find it useful to visit the charity website Beat for more information.
Where did the story come from?
The researchers who carried out the study were from the Institute of Psychiatry, the South London and Maudsley NHS Foundation Trust, Imperial College London, the University of Exeter, Queen's University Belfast, University of Bristol and University of Liverpool. The study was funded by the National Institute of Health Research and published in the peer-reviewed journal BMJ Open, which is available to read free online.
The study was covered in The Sun and The Guardian. Both reports focus on the apparent doubling of the rate of anorexia in children aged 8 to 12, although this represented only a small number of cases in absolute terms.
What kind of research was this?
This was a cross-sectional study, using data collection cards sent to doctors every month over 1 year to ask if they had seen any new cases of eating disorders. This type of study can help assess how many people are being newly diagnosed with a condition. The main problem was that many of the cards were not returned, meaning that the researchers had to estimate what the missing cards might have shown. Additionally, such studies can only show observations. They cannot explain the potential reasons for any change.
What did the research involve?
The researchers used the Child and Adolescent Psychiatry Surveillance System, which sends out cards each month to child and adolescent psychiatrists working in the NHS. The researchers asked psychiatrists to notify them of any new diagnoses of rare mental health conditions among young people.
When new cases of anorexia were reported, the doctors were sent questionnaires asking them to provide more information about their patients. This was to confirm they had anorexia according to standard diagnostic criteria, to check they were not being recorded more than once, and to gather information on their condition and characteristics.
These included: NHS number (or Community Health Index number, as it is known is Scotland), sex, date of birth, ethnic background, weight and height, percentage of expected body mass index, and scores on tests of behaviour, symptoms, social functioning and other health-related factors.
The researchers identified eligible cases, who were aged 8 to 17, with no previous episode of anorexia treated by child and adolescent health services, assessed during the study period, and with clinical symptoms diagnostic of anorexia. They used the data to calculate incidence rates per 100,000 children or young people in this age group.
Where cards had not been returned, the researchers assumed that half of the non-returned cards were negative (no new cases of anorexia). The other half followed the split between diagnoses and no diagnoses as seen in the returned cards. Where doctors had not sent follow-up information, they assumed that the eligibility rate for inclusion in the study was the same for the unreturned information as for the returned follow-up information.
What were the basic results?
Half of the notification cards sent to doctors during the study period were returned. From those returned, 997 cases of anorexia were reported during the 8 months of the study. After removing those where no further information was received, or those that were ineligible for inclusion in the study, the researchers had 305 confirmed cases. Of these:
- 91.48% were girls
- 91.64% were white
- the average age was 14.56 years
- the average body mass index (BMI) was 16.50, suggesting moderate severity of anorexia
After adjusting their figures to take account of unreturned cards and follow-up information, the researchers calculated that the annual number of new cases of anorexia was 13.68 per 100,000 young people aged 8 to 17 years.
The figures increased as children grew older:
- 0.43 in every 100,000 8 year olds
- 3.65 in every 100,000 11 year olds
- 19.95 in every 100,000 13 year olds
- 30.37 in every 100,000 16 year olds
Previous UK figures for young people aged 13 or over were not available for comparison.
How did the researchers interpret the results?
The researchers said that "firm conclusions relating to changes in incidence rates over time" could not be made, because of lack of evidence, but that "service providers and commissioners should consider evidence to suggest an increase in incidence in younger children".
Headlines reporting that anorexia rates have doubled in younger children sound alarming. While any cases of anorexia among young people are certainly cause for concern and need urgent specialist care and treatment, we should keep in mind that the actual number of children under 12 with anorexia remains very small.
Anorexia is more common among teenagers, especially girls, but even then the overall population rate remains fairly low – affecting 0.03%, or in 1 in 3,000, at the highest estimate.
There are issues to be aware of that may make the estimates less reliable. Only half of the reporting cards sent out to child and adolescent psychiatrists during the study were returned. Although the researchers explain their methods for estimating the numbers of new anorexia diagnoses that might have been on the missing cards, we have no way of knowing if those estimates are accurate. We do not know why the doctors did not return the cards.
The study only captures assessments and diagnoses of new cases of anorexia as confirmed by specialist services. UK guidelines say that children who may have an eating disorder such as anorexia should be assessed by a specialist psychiatrist. However, not all young people with anorexia may have seen by a GP and been referred for specialist assessment. So the figures may underestimate the scale of the problem.
While childhood obesity is more often discussed in the media, eating disorders such as anorexia are serious, can cause life-long problems and in some cases are life-threatening. If you're concerned your child or another young person in your care may have an eating disorder, make an appointment for them to see a GP as soon as possible. The sooner they get help, the better chance they have of making a full recovery.
Analysis by Bazian
Edited by NHS Website
Links to the headlines
The Guardian, 23 October 2019
The Telegraph, 22 October 2019
The Sun, 23 October 2019
Links to the science
BMJ Open. Published online 22 October 2019