Diseases such as coeliac disease and Parkinson’s could be diagnosed up to 10 years earlier than they currently are, a new study suggests.
By examining patterns in the use of healthcare services before diagnosis, researchers from University College London (UCL) established that some conditions may have clear ‘diagnostic windows’ that can be used in principle to give a much earlier diagnosis of certain illnesses.
The findings, published in the British Journal of General Practice, show for the first time that diagnostic windows may exist for many health conditions and hold promise for improving disease diagnosis.
Diagnostic windows are well established for cancer diagnoses but remain relatively unexplored for other non-neoplastic conditions, where cell proliferation is not due to abnormal tissue growth. The researchers screened 4,340 studies on Pub Med and Connected Papers and reviewed 27 in detail to establish whether diagnostic windows could be applied to other diseases.
The studies analysed covered 17 non-neoplastic conditions, including chronic conditions such as Parkinson’s disease and acute conditions such as strokes. The researchers looked at patterns in pre-diagnostic healthcare use, such as visits to primary care and presentations with relevant symptoms.
For nine conditions, there was sufficient evidence to determine a diagnostic window presence and length.
The windows ranged from 28 days for herpes simplex encephalitis to nine years for ulcerative colitis.
Overall, healthcare use increased years before diagnosis for chronic conditions such as Parkinson’s disease, coeliac disease, schizophrenia, and inflammatory bowel disease, suggesting significantly earlier diagnosis might be possible for some patients.
For relatively acute conditions such as tuberculosis and herpes infection, the change in healthcare use occurred between one and six months, and the diagnostic window was much closer to diagnosis.
The researchers found that although diagnostic windows were likely present for the remaining conditions, within this review, there was insufficient evidence to accurately determine their length.
Lead author Emma Whitfield, a PhD student at UCL, said: ‘In the last 20 years, researchers have put much time and effort into improving the diagnosis of cancer.
‘A body of literature has built up with novel concepts, such as the ‘diagnostic window’, that haven’t been comprehensively applied to other diseases, and this was the motivation for our study.
‘This initial evidence suggests that, if improvements can be made to the diagnostic process, there is potential to diagnose some patients with these conditions earlier.’