Development of outcome measures for giant cell arteritis for use in clinical trials and standard practice.

For daily clinical practice, outcome measures should reflect the patients' disease activity status and have to be easily assessed and recorded. The study identified composite outcome measures for GCA able to assess the disease state and monitor response to therapy. Key Points • Despite the cohort studies published in giant cell arteritis (GCA), there are no fully validated outcome measures for use in standard practice or clinical trials. • There is a gap in international standards for assessing GCA disease activity. • Identifying disease specific outcome measures is vital for monitoring response to therapy, treatment case series and therapeutic clinical trials in GCA. • This study was carried out aiming to classify the outcome measures for GCA with a discriminative ability to identify the disease activity status and response to therapy.