Newswise — SAN FRANCISCO — People diagnosed with rheumatoid arthritis after the year 2000 don’t have as much of an increased risk of death as people diagnosed before 2000, according to research presented this week at the American College of Rheumatology Annual Meeting in San Francisco. This, suggests the researchers involved in the study, is likely due to better treatments that focus on eradicating inflammation – a major contributor to the increased risk of death in RA.
Rheumatoid arthritis is the most common chronic autoimmune disease that affects the joints. RA has the potential for joint damage and deformity, with loss of function. The cause of RA is unknown. It affects people of all ages, and women more commonly than men. RA causes pain, stiffness and swelling, generally in multiple joints. RA may affect any joint, but the small joints in the hands and feet are most frequently involved. Rheumatoid inflammation may also develop in other organs such as the lungs.
While increased death among people with RA has long been established, recent discoveries in the treatment of this disease have raised the question of whether deaths in RA would start declining. This becomes a particularly important question as treatment plans are now, more than ever, focused on lowering inflammation in the body.
As a part of a retrospective cohort study, a group of Canadian researchers recently reviewed the health information — gathered from physician visits and death certificates — of 24,914 people with new onset of RA and matched each of those people’s information with someone of the same gender and birth year, but who did not have RA. They were also matched based on the year they were included in the study, which ranged from January 1996 to December 2006. Matching to these three characteristics ensured similar people were being compared to one another.
People with RA were selected for the study if they had two or more physician visits more than two months apart for their RA (between 1996 and 2006) and had no prior RA-related doctor visit from 1990 onwards. People who had two or more subsequent physician visits for another inflammatory arthritis (e.g., psoriatic arthritis, ankylosing spondylitis, lupus, etc.); people who saw a rheumatologist, but were never confirmed to have RA; and people who didn’t have subsequent RA follow-up visits over the course of five years were not included in the study.
“It has been recognized for one to two decades that the risk of death is increased in RA compared to the general population, and this seems to be linked to inflammation, as people with more severe disease and more active inflammation are at greater risk for death,” explains lead investigator in the study, Diane Lacaille, MDCM, FRCPC, MHSc; professor, Division of Rheumatology, University of British Columbia; senior scientist, Arthritis Research Canada. “Since we now have more effective treatments for RA and since here has been a paradigm shift in our approach to treating RA, recommending early and aggressive treatment with DMARDs with the aim of eradicating inflammation, we would hope that this new strategy of treating RA would lead to improvement in mortality. Our study aimed to evaluate whether the risk of mortality in RA compared to the general population has improved over time, as we have been treating the inflammation of RA more effectively.”
Once each participant with RA was matched with a similar participant without the disease, Dr. Lacaille’s team further divided the participants by splitting them into groups based on the year they were diagnosed. The ‘early’ group was diagnosed between 1996 and 2000, while the ‘later’ group was diagnosed between 2000 and 2006. This segmentation not only allowed the researchers to compare death rates of people with RA versus people without; it allowed them to determine if the introduction of new treatment strategies in the 2000s impacted death rates in those patients who were diagnosed in an era when biologics were available and RA treatment was shifting towards earlier and more aggressive DMARD treatment.
The participants studied were predominately women (66.5%) with an average age of 57 years. Those with RA were followed for 112,431 person years (which is the number of people in the study multiplied by the number of years they were studied), and the group without RA were followed for 113,000 person years. During the study, the researchers noted 2,747 deaths among the group of participants with RA and 2,123 in the group without. These deaths converted to mortality rates of 24.43 and 18.77 deaths per 1,000 person years, respectively.
When looking at the subgroups created based on year of diagnosis, the researchers found that there were significantly more deaths among participants in the ‘early’ group when compared to their study partners without RA; this was not the case in the ‘later’ group, and this finding remained the same when researchers looked at different causes of death, such as cardiovascular disease and cancer. This was not true of deaths due to infection, however, which was not different between the early and later groups.
According to Dr. Lacaille, one of the limitations of this study is that to have the same follow-up time in all groups, the researchers had to limit follow-up to five years. Yet, some of the greatest increases in mortality risk occur after longer disease. So, the researchers believe it will be important to see if this mortality improvement is sustained with longer follow-up.
In all, the study shows that the increased risk of mortality observed in RA compared to the general population, which is felt to be due to uncontrolled inflammation, has improved over time. “These findings should be reassuring to patients and clinicians,” says Dr. Lacaille. “It suggests that in recent years, as we have been more successful in treating rheumatoid arthritis and controlling inflammation, we have improved, and possibly even closed, the mortality gap between RA patients and the general population.”
About the American College of RheumatologyHeadquartered in Atlanta, Ga., the American College of Rheumatology is an international medical society representing over 9,400 rheumatologists and rheumatology health professionals with a mission to Advance Rheumatology! In doing so, the ACR offers education, research, advocacy and practice management support to help its members continue their innovative work and provide quality patient care. Rheumatologists are experts in the diagnosis, management and treatment of more than 100 different types of arthritis and rheumatic diseases. For more information, visit www.rheumatology.org.
About the ACR/ARHP Annual MeetingThe ACR/ARHP Annual Meeting is the premier meeting in rheumatology. For more information about the meeting, visit www.acrannualmeeting.org/ or join the conversation on Twitter by using the official #ACR15 hashtag.
ACR Abstract 1999 www.acrabstracts.org/