A new study, published in the journal Annals of Human Biology, has found that the current methods used by immigration bodies, local authorities and the Fédération Internationale de Football Association (FIFA) to assess an individual's age to be inaccurate in more than a third of all cases.
Age assessment uses markers of physical growth and development to assess an individual's developmental age, and it is used in certain circumstances to check a person's stated chronological age, being the number of years they have lived.
It is a crucial tool for immigration bodies and local authorities when receiving asylum seekers, to decide if they are a child under 18 or an adult. This is because there are often no official documents available to verify a child's age. To judge an age inaccurately could lead to vulnerable children not receiving the appropriate care and protection they need, or adults receiving access to limited care services intended for children.
Age assessment can also be used to check a person's claimed chronological age in professional sport, and is used by FIFA to check for over-age players in international under-17 football competitions.
Study author Tim Cole, professor of medical statistics at University College London (UCL) Institute of Child Health, reviewed the current literature on three different methods of age assessment to assess bone age and dental age: X-rays of the hand-wrist, Magnetic Resonance Imaging (MRI) scans of the wrist, and X-rays of the third molars (wisdom teeth). In addition, he conducted a meta-analysis of seven international studies, totalling nearly 7000 subjects, assessing the use of X-ray scans of third molars to determine age.
For the hand-wrist X-ray, he found many individuals with a mature X-ray are under 18, whilst many with an immature X-ray are over 18. This means bone age based on hand-wrist X-rays can result in some children being assessed as adults, and some adults being assessed as children, and because of these risks he recommends it should not be used.
The study found age assessment based on an MRI scan of the wrist or X-ray scan of the third molar to be less inaccurate. Most individuals with mature scans are over 18, but at the same time those with immature scans may be under or over 18. This presents a risk of adults with an immature scan being wrongly assessed as children.
Overall, he found the three methods to be very inaccurate, with over a third of all age assessments proving wrong.
Tim Cole, of UCL Institute of Child Health, said: "The results of my research show that current methods used to assess developmental age in the UK do not work well. It is important their inaccuracy is widely realised so that where age is assessed based on physical development, the quality of evidence can be challenged.
"Other more holistic methods of age assessment need to be explored."
The research was funded by the Medical Research Council.