Using a statistical analysis technique called item response theory (IRT), the researchers were able to reduce an existing nine-item survey down to four items. The survey, known as the Simple Clinical Colitis Activity Index (SCCAI), is used by medical professionals to monitor progress of the disease without the need for physical assessment.
Once validated, the findings pave the way for the SCCAI to be improved upon and implemented clinically. Ulcerative colitis is a long-term condition where the colon and rectum become inflamed. For some people, the condition has a significant impact on their everyday lives, and tracking symptoms can help clinicians assess when treatment (for example, with steroids) may need to be increased or reduced.
The study’s senior author is Dr Sarah Bauermeister, Senior Data and Science Manager at Dementias Platform UK (DPUK), whose areas of research interest include psychometric testing. Dr Bauermeister said: ‘The field of psychometrics was initially developed to measure the progress of children in schools, and over time it has become more sophisticated, making use of approaches like automation and item response theory. These advanced techniques have only recently begun to be adopted in the healthcare sector, where many of the scales and tests used by clinicians have been in place since the 1940s or 1950s and haven’t been challenged. There is an acknowledgement in the sector, however, that the colitis scale in particular could be improved.
‘In this study, we used IRT mathematical modelling to work out which items in the survey were redundant. This has refined the scale down to just four key questions, which could substantially reduce the burden on patients and make sure clinicians have only the most useful information.’
Data for the study was collected through TrueColours, a real-time software platform that allows remote symptom entry and monitoring of people with ulcerative colitis. Patients can enter their symptoms daily via mobile phone. The data, from 516 patients, was then uploaded securely to the DPUK Data Portal for analysis, demonstrating both the efficient integration of two data platforms and the potential of the Data Portal for investigation of non-neurological conditions.
After IRT analysis, four items remained in the SCCAI scale: bowel frequency day; bowel frequency nocturnal; urgency to defecation; rectal bleeding.
Study author Dr Alissa Walsh, a consultant gastroenterologist at Oxford University's Translational Gastroenterology Unit, added: ‘The TrueColours platform has been successfully integrated into clinical practice in Oxford. Using validated indices to track symptoms, quality of life, and outcomes such as the need for hospitalisation, TrueColours is allowing a more personalised approach to be implemented. Not only does this improve our patients’ clinical care, it has also allowed collaboration with mathematicians in Oxford.
‘Data collected through the TrueColours programme over the past five years has now led to an enormous amount of very granular data, never before collected in this field. Due to the fluctuating and often unpredictable course of disease, symptom data is crucial in a disease such as ulcerative colitis. Dr Bauermeister’s team has been enormously helpful in applying IRT to our ulcerative colitis data. Put simply, we are currently asking nine questions every day, whereas we now know that only four of these questions are truly helpful. This work will need to be validated – however, it is an exciting step forward.’
Read the full paper, ‘Using Item Response Theory (IRT) to Improve the Efficiency of the Simple Clinical Colitis Activity Index (SCCAI) for patients with ulcerative colitis’. The research is published in the journal BMC Gastroenterology and was carried out by scientists and clinicians based at the John Radcliffe Hospital and the Warneford Hospital in Oxford.
The TrueColours platform is run from Oxford University’s Department of Psychiatry.