Outcomes

Outcomes evaluate the impact of disease. In rheumatology they span measures of disease activity, end-organ damage, and quality of life. Some outcomes are categorical, such as the presence or absence of remission. Other outcomes involve extended numeric scales such as joint counts, radiographic scores, and quality of life measures. Outcomes can be measured in the short term—weeks and months—or over years and decades. Short-term outcomes, though readily related to treatment, may have less relevance for patients. Clinical trials focus on short-term outcomes whereas observational studies explore longer-term outcomes. The matrix of rheumatic disease outcomes is exemplified by rheumatoid arthritis. Its outcomes span disease activity assessments like joint counts, damage assessed by erosive scores, quality of life evaluated by disease-specific measures like the Health Assessment Questionnaire (HAQ) or generic measures like the Short Form 36 (SF-36), overall assessments like remission, and end result such as joint replacement or death. Outcome measures capture the impact of treating rheumatic diseases. They are influenced by disease severity and effective treatment. They also reflect many confounding factors. These include demographic factors like age, gender, and ethnicity and also deprivation, as poverty worsens outcomes. Comorbidities affect outcomes and patients with multiple comorbid conditions have worse quality of life with poorer outcomes. Patient self-assessment has grown in importance; it is simple and understandable. However, self-assessment can vary over time and does not always reflect assessors’ perspectives. Caution is needed comparing outcomes across units; the various confounding factors and measurement complexities make such comparative analyses challenging.