Expanding disease definitions under scientific scrutiny

March 9, 2017

Prestigious national award granted to investigate why so many people are being diagnosed and treated for diseases that won’t harm them

The problem of expanding disease definitions will come under close scientific scrutiny, with a Bond University academic this week winning a major national research award to investigate the phenomenon.

Dr Ray Moynihan, an internationally respected academic and author, has just won a four-year fellowship from the federal government’s National Health and Medical Research Council (NHMRC) to investigate the problem of overdiagnosis – a problem which happens when someone is diagnosed with a disease that won’t actually harm them.

“Overdiagnosis happens for a lot of different reasons – including the best of intentions - but as doctors continue to lower the thresholds at which someone is classified as sick, more and more healthy people are being redefined as patients,” Dr Moynihan said.

Examples of expanding disease definitions that have sparked scientific controversy include:

  • a recent expansion of the definition of gestational diabetes – which will more than double the number of pregnant women classified as sick
  • a new definition of “chronic kidney disease” which labels almost half of all elderly people, including many who will never experience kidney disease
  • changes to the way ADHD is diagnosed, that may further expand the numbers of children and adults who are labelled

A Senior Research Fellow at Bond’s Centre for Research in Evidence-Based practice who obtained his PhD in 2015, Dr Moynihan’s most recent research examined the example of osteoporosis – where the formal definition automatically labels many healthy older women who will never experience a fracture as “diseased”.

Under the supervision of world-class researcher, Bond University’s Professor Paul Glasziou, Dr Moynihan plans to investigate how and why so many disease definitions are expanding, in order to better respond to the problem of overdiagnosis.

“Some disease definitions are changing dramatically and overdiagnosis is a genuine threat to the sustainability of our health system,” Professor Glasziou said.

The purpose of the NHMRC’s fellowship is to provide opportunities for Australian researchers of outstanding ability to undertake research that is both of major importance in its field and of benefit to Australian health.

"Winding back unnecessary tests and treatments, unhelpful labels and diagnoses won’t only benefit those who directly avoid harm, it can also help us create a more sustainable future." 
                                                                                      Dr Fiona Godlee, Editor-in Chief, BMJ