'Am I doing this right?' Physician perceptions of the global assessment in clinical trials of systemic sclerosis

Physician global assessments (PhyGAs) are commonly performed in randomized controlled trials (RCTs) in SSc. However, there is no single PhyGA applied across RCTs. We performed an exploratory qualitative study to explore perceptions of the PhyGA, its role in RCTs and how physicians perform their own assessment.

Participants with expertise in the clinical assessment and, or actively involved in research on SSc were invited to participate. Participants were asked to define disease constructs of activity, damage, severity, and overall health, and to describe how they perform a PhyGA and their perception of what a PhyGA should assess. Interview transcripts were analysed using deductive and inductive thematic analysis.

Eighteen rheumatologists and one patient research partner were interviewed. Four major themes were identified: (i) physician uncertainty; (ii) variation in the conduct of a PhyGA; (iii) physician efforts to improve PhyGA consistency; (iv) utility of a PhyGA. Most participants felt a PhyGA should assess changeable aspects of SSc, commonly conceived of as disease activity. There was considerable uncertainty about the optimal method for assessing disease activity. Participants were uncertain about their own methods of performing a PhyGA, and variability in the application of the instrument was identified. Despite these limitations, physicians generally agreed that the PhyGA is useful and can assess unquantifiable aspects of SSc.

We identified significant heterogeneity in the approach to PhyGAs in SSc. This variation was considered a limitation of the PhyGA. Overall, a PhyGA was viewed as a useful instrument that can aid the assessment of treatment response in RCTs.