Table 2 Major strengths and weaknesses of PGA in RA
Strengths | Weaknesses |
|---|---|
Practical and feasible to collect: much more easily collected than joint counts, acute phase reactants, or radiographic damage (simple, single-item tool) | Heterogeneity in concept (i.e., global health versus disease activity) and attribution to RA or other co-existing health conditions and wording/phrasing, all leading to possible heterogeneity in the responses |
No cost, non-invasive and self-administered | Heterogeneous phrasing of the time-frame (today, last week, etc.) applied to PGA |
May summarize all aspects of disease important to the patient (face validity) | Very broad concept leading to interpretation difficulties |
Practical and feasible to interpret: easy to score, incorporate in composite scores, and analyze | Difficulties of interpretation due to uncertainty regarding attribution to permanent damage related to RA compared to inflammation and disease activity |
Good test–retest reliability | Difficulties of interpretation due to uncertainty regarding attribution to RA versus non-RA disease, including psychological distress and comorbidities |
Good sensitivity to change in clinical trials | May be influenced by patient education level |
Discordance between PGA and physician assessment: brings in additional information | Discordance between PGA and physician assessment: what impact on decision making? |