Innovative measurement of fatigue: The CAT fatigue RA

Severe fatigue is a highly prevalent and bothersome symptom for patients with rheumatic diseases. Existing fatigue questionnaires have several disadvantages, for example containing generic fatigue items that might be confounded by disease specific disability, or being unidimensional, which is not in line with the patients´ experience of their fatigue symptoms. Therefore, we developed a multidimensional computerized adaptive test (CAT) which was based on the perspectives of patients with RA. In a CAT, items are successively selected from a large item bank (scaled using IRT), based on the patient’s previous answer. Measurement is thus tailored to the individual level, leading to greater measurement precision, with need of fewer items than traditional questionnaires. We studied the usability of CAT administration, demonstrated the working mechanisms of a computer adaptive test and validated the CAT.

Post-doc Researcher

Stephanie Nikolaus


Christina Bode

A crosswalk for converting scores on different patient-reported outcome measures

Many questionnaires are available that measure the same health-related construct such as physical functioning. In this project we developed a crosswalk for converting scores on two of the most frequently used measures of physical functioning. The crosswalk was developed using a novel approach of item response theory (IRT) based methods in Dutch patient with rheumatoid arthritis. More recently, the generalizability and accuracy of the crosswalk was demonstrated in patients with different rheumatic diseases in the United States as well. The methodology and crosswalk developed in this study provide an important step in achieving better interpretation and comparability of results across different studies and populations.

Post-doc Researcher

Martijn Oude-Voshaar


Peter ten Klooster

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Web-based Patient Decision Aid (PtDA) to improve shared decision making about Anti-Rheumatic Drugs (DMARDs)

To facilitate shared decision making in rheumatology, we developed a patient decision aid (PtDa) in co-creation with patients, rheumatologists and nurses. The PtDA consists of the following parts: [1]

general information about Shared Decision-Making, inflammatory arthritis and DMARDs; [2] an

application to compare particular DMARDs based on the suggestions of the rheumatologist; [3]

exercises to gain insight in personal preferences, worries and questions; [4] a printed summary with patients’ notes, preferences, worries and questions, to be discussed with the rheumatologist at the next consultation. The PTDA is currently evaluated in a quasi-experimental study and can be seen at:

PhD Candidate

Ingrid Nota


Stans Drossaert