In recent years, tremendous strides in understanding how RA develops has led to the development of targeted therapies.

The aggressive use of disease-modifying anti-rheumatic drugs (DMARDS) such as methotrexate, in combination with biologic therapies has resulted in sustained effectiveness, improved tolerability, and better response levels. The result has been a significant reduction in joint damage and work-related disability.

Remission is now the norm rather than the exception in patients who are seen early. The concept of a narrow window of opportunity- usually the first 3 to 6 months of disease- where aggressive therapy can prevent deformity and disability has also been recognized as a major reason for the improved prognosis.

Despite these advances, several problems still remain. A large number of patients stop treatment for a variety of reasons including lack of response and side effects. It is unclear whether the new drugs being used can actually help joint damage to heal. Long-term side effects also remain a concern.

So how do rheumatologists make the decision to change therapy?

The first question that needs to be resolved is "what is an inadequate response?" The definition is not an easy one.

There are actually three answers. The first is what is called primary failure where the drug doesn't lead to any kind of improvement right from the outset. Secondary failure occurs when the drug works initially but then over time, the beneficial effects fade. Finally there are side effects and other toxicity issues to consider.

Another very important factor is the patient's own feelings as to how they are doing. What are considered are both pain relief as well as ability to function with activities of daily living.

Added to this mix is the result of different imaging modalities such as magnetic resonance imaging, ultrasound, and plain x-ray. Of these three, plain x-ray is the least sensitive and least useful method.

Laboratory parameters that measure systemic inflammation such as the erythrocyte sedimentation rate (ESR) and C-reactive protein are also used in decision-making.

Some rheumatologists advocate the use of measuring devices of disease activity. They have the following names: Disease Activity Score (DAS), Disease Activity Index (DAI), and Global Arthritis Score(GAS). These measuring devices all involve analyzing different disease parameters, scoring them, then coming up with a number. The higher the number or score, the worse the patient is doing. These different scoring methodologies have a few things in common. They usually incorporate some count of swollen and tender joints. They also usually require adding in one of the laboratory measures of inflammation. Some also add in the results of a patient's Health Assessment Questionnaire. This latter item tallies the patient's ability to perform routine daily activities. Finally some methods also incorporate a patient self-assessment.

There is no consensus as far as which tool is the best to use. There is growing interest though in using the tools more often than they are being used now. Stay tuned.