Overview of Comorbidity and Arthritis

Comorbidity or a comorbid condition is the presence of two or more diseases or conditions that occur together in the same person at the same time.

Conditions considered comorbidities are often long-term or chronic conditions, and they may or may not be associated with each other. Other terms that are often used interchangeably with comorbidity include coexisting conditions, co-occurring conditions, multimorbidity, or multiple chronic conditions (although important distinctions differentiate these terms).

Comorbidity and Arthritis

Rheumatoid arthritis (RA) is a condition that has many comorbidities as well as nonarticular manifestations. Nonarticular manifestations of RA differ from comorbidities in that they are caused by RA, but they manifest in other parts of the body other than joints.

Nonarticular manifestations of RA include subcutaneous rheumatoid nodules, vasculitis, neuritis, Sjogren's syndrome, and Felty's syndrome. Although these conditions don't affect everyone who has RA, they are considered part of the disease. And, when present, they may influence treatment.

Comorbidities are diseases and conditions that aren't caused by RA, such as when RA occurs along with diabetes, heart disease, cancer, dyslipidemia, obesity, cardiovascular disease, or depression.

Comorbidity Statistics

Nearly half of adults in the United States with arthritis also have at least one other chronic condition. While heart disease is the most common, diabetes, obesity, high cholesterol, and chronic respiratory conditions are high on the list as well.

The Centers for Disease Control reveal that in the United States:

• 49 percent of adults with heart disease also had arthritis.
• 47 percent of adults with diabetes also had arthritis.
• 31 percent of adults who are obese have arthritis.

Comorbidities with RA can occur with a higher frequency than would be expected in the normal population, but they aren't caused by each other. And they may lead to the development of anxiety and depression as people face multiple treatments and high medical costs.

Why Is Comorbidity Common With Arthritis?

It is common for people with arthritis to have comorbidities. This is related to non-modifiable risk factors as well as modifiable risk factors that are associated with arthritis and comorbidities.

Age is a non-modifiable risk factor that increases the risk of RA and many of its comorbidities. Obesity and smoking are examples of shared modifiable risk factors. The CDC has emphasized the importance of remaining physically active to help manage arthritis as well as many of its comorbidities.

Despite the emphasis on remaining active:

• 1 in 5 people who have heart disease or diabetes is physically inactive.
• 1 in 3 people who have arthritis and either heart disease or diabetes is physically inactive.

Arthritis reduces physical activity, which increases the adverse effects of its comorbidities.

General Consequences of Comorbidity

Generally, comorbidity is tied to worsening health outcomes, the need for more complex treatment and disease management, and higher healthcare costs.

It's not unusual to be faced with managing multiple chronic conditions. In 2017, nearly 67 percent of Medicare fee for service spending went to people with two or more chronic conditions. Medicare beneficiaries with six or more conditions make up only 17% percent of Medicare beneficiaries, but the cost of care for this group is nearly 53% percent of total expenditures.

Another point that researchers have considered with regard to comorbidity is which disease occurred first. For example, knowing whether arthritis or depression developed first may have implications regarding disease prognosis and treatment.

When treatment options are selected, it is important to recognize and steer clear of treatments that are antagonistic. Using a particular treatment for one condition may further complicate the other.

What You Can Do

Researchers are increasingly concerned about the rise in comorbidity among people with arthritis.

Treatments for multiple conditions can include problems like getting conflicting medical advice, duplicative tests, or adverse medication effects. The medical community is recognizing this and many healthcare providers are working on a more team-based and patient-centered approach.

If you have other conditions along with your arthritis, speak to your healthcare provider and healthcare team about ways to address the problems you face. Increasing your physical activity, coordinating your healthcare provider appointments and tests, and properly managing your medications are a few strategies that can help you cope with your comorbidities.

Although some people prioritize one of their health conditions over the others, this is not the best idea. It's recommended that you work with your healthcare providers to devise a healthcare plan that addresses your entire health. This can lead to a higher quality of life.