The diagnostic window is a common concept in oncology. The researchers applied it to ulcerative colitis and other conditions.
With many chronic conditions, delayed diagnosis is associated with a worse prognosis. For ulcerative colitis, a delayed diagnosis has been linked to a higher risk of intestinal surgery and increased use of biologics.
A diagnostic window is defined as the period during which a diagnosis may be theoretically possible in some patients with a given condition. The length of a diagnostic window typically ranges from a few months to a few years, with chronic conditions having longer diagnostic windows than more acute conditions.
Diagnostic windows are generally well-established and accepted in oncology. However, the concept has rarely been studied in other therapeutic fields.
In a study published last month in the British Journal of General Practice, researchers from University College London (UCL) conducted a systematic review of healthcare utilization during the weeks, months, and years prior to diagnosis of various conditions. The aim was to derive evidence of the existence and length of diagnostic windows in conditions outside of oncology.
Lead author Emma Whitfield, Ph.D. candidate at UCL Institute of Epidemiology and Health Care and UCL Institute of Health Informatics, and colleagues looked at 27 studies and analyzed prediagnostic healthcare utilization for 17 conditions, including ulcerative colitis. The researchers found that healthcare use increased years before diagnosis for chronic conditions, such as Parkinson’s disease, schizophrenia, and inflammatory bowel disease. According to the authors, this data suggests that some chronic conditions may be diagnosed significantly earlier than usual. For ulcerative colitis, the diagnostic window could be as long as nine years.
The authors comment that identifying diagnostic windows can help select patients that may benefit from targeted therapies. However, further research is necessary to determine how early diagnosis may be achieved and the methods by which this may be accomplished.
“Although the existence of diagnostic windows for a given condition does not prove that any individual patient could have been diagnosed earlier, it provides ‘proof-of-concept’ that earlier diagnosis is possible for some patients, while pointing to possible avenues for improvement,” wrote Whitfield and her colleagues. “Further research is required to identify missed diagnostic opportunities for specific conditions.”