Methotrexate is a highly effective treatment for rheumatoid arthritis (RA).  For some patients, this medication works very well to control the disease and help them maintain a good quality of life.  For others, methotrexate may not be suitable due to its side effects, or other medical conditions (comorbidities) can mean that methotrexate is not recommended.  Furthermore, some people might respond only partially to methotrexate and need to take additional medication to treat RA.  If it was possible to predict who was likely to respond well to Methotrexate, we would be able to start the most suitable treatment for each patient at the very beginning of their treatment journey, rather than using trial and error to find out which medication was best.  This is sometimes called personalised medicine.

One of the problems restricting research into personalised medicine for RA is that people with comorbidities are less likely to be involved in clinical trials of drug treatments, due to concerns over the safety of using newer drugs or regimes in patients who may be at greater risk of suffering harm from such trials. One way of finding out how best to treat RA in people with comorbidities is to use observational cohort studies.  Instead of offering new or different treatments, cohort studies simply observe what happens when standard care is given.  A common problem amongst RA cohort studies is that information on comorbidities is usually obtained by asking the patient to recall details of other illnesses, usually only at the start of the study.  This means that details of comorbidities may be incomplete and are not usually updated as the study progresses over time, which is often years.

We are planning to use information collected by general practitioners (GPs) in their practices (primary care) to improve the information on comorbidities available within our RA research cohorts.  We will create a larger database containing not only the Leeds RA cohort data, but also details of comorbidities gathered from primary care and data collected from parallel genetic studies. Once this is established, we can conduct research to find out how to identify patients likely to respond to methotrexate, using the important comorbidity data to help make this information useful for treating individual patients. Once we have perfected this approach it will be possible to expand our research to study other treatments and study the long-term outcomes of patients with RA.