Three new studies presented at the European League Against Rheumatism Annual Congress (EULAR 2015) have provided valuable guidance on measuring fatigue and optimising its treatment in Rheumatoid Arthritis (RA) patients, and in patients with other rheumatic diseases. Fatigue remains a frequent and debilitating problem for patients with RA that needs to be addressed.

Findings from these studies show:

  • Chronic fatigue in RA patients has been identified as not being well managed by healthcare professionals, with 79% claiming their fatigue had never been measured; today's recommendation is that validated fatigue measurements should be used to improve patient outcomes
  • New criteria are being developed including measures to reliably identify patients with clinically significant fatigue
  • Contrary to expectation, transient changes in fatigue do not appear to be associated with transient changes seen in RA disease activity; this in turn indicates that treatment aimed at achieving disease remission is not likely to be an effective approach to treating fatigue

Researchers have been studying the link between fatigue and RA for over 20 years. Due to differences in definition and measures, varying prevalence rates have been reported, with one major study describing clinically important levels of fatigue in 42% of RA patients; while other studies have found prevalence rates of fatigue in adults with RA of 80% and more.

Validated fatigue measures needed to improve clinical management of fatigue in RA patients

To quantify the impact of chronic fatigue on RA patients and understand how it is managed, the UK patient association - the National Rheumatoid Arthritis Society - surveyed over 2,000 people with RA about their experiences.

"One of the most important findings was that chronic fatigue in RA patients is not being well managed by healthcare professionals: 66% of respondents had never or rarely been asked about it, and 79% said their fatigue had never been measured," said Ailsa Bosworth of the National Rheumatoid Arthritis Society, Maidenhead, United Kingdom.

"Clinical guidelines in the UK contain few references to the effective management of chronic fatigue in RA. If we want to improve the management of fatigue associated with RA, use of validated fatigue measurements will be an essential component to the revision of our current clinical guidelines," Ms Bosworth concluded.

New criteria being developed to reliably identify rheumatic patients with clinically significant fatigue

Fatigue is common across rheumatic diseases and is a crucial determinant of quality of life. However, most studies use single questions or scores above a cut-off point on a continuous measurement scale to define fatigue. The lack of agreed-upon standards for identifying clinically significant fatigue hinders research and clinical management.

According to Dr. Linda Kwakkenbos of McGill University and the Jewish General Hospital, Canada, "harmonising definitions and measurement to identify fatigue that is clinically significant will advance research and greatly increase the potential for effective treatment."

Dr. Kwakkenbos and colleagues compared the performance of the Cancer-Related Fatigue case definition criteria in women with breast cancer and systemic sclerosis and found that, by omitting two cognitive fatigue symptoms, it could be used to reliably identify patients with Chronic-Illness Related Fatigue among systemic sclerosis patients.

The Cancer-Related Fatigue interview was completed by 291 women with systemic sclerosis and 278 women successfully treated for breast cancer.

Transient changes in fatigue not associated with transient changes in disease activity

Investigators working on behalf of the Society for Rheumatology Research Utrecht have used a statistical model to compare the association between levels of fatigue and RA disease activity.

"We were surprised to find that, not only is there hardly any association between levels of fatigue and RA disease activity between different individuals, but also changes in fatigue are not associated with fluctuations in disease activity in specific patients," said lead investigator Professor Rinie Geenen of the Department of Clinical and Health Psychology University Medical Centre Utrecht, Netherlands.

"This lack of association between fatigue and objective disease activity markers in patients with RA is counterintuitive since patients and doctors consider fatigue an indicator of underlying disease activity," Professor Geenen explained. "This indicates that treatment directed at disease remission is hardly a means to treat fatigue," he concluded.

Patients with RA (n=248, mean age 53 years, 76% female, 56% rheumatoid factor positive) receiving biologics were monitored at the start of treatment, and at three and six month intervals. Fatigue was assessed with a visual analogue scale (0-10), and disease activity with the erythrocyte sedimentation rate and swollen joint count (28 joints).