Surveys conducted in a large number of patients with rheumatoid arthritis (RA) have allowed researchers to determine the point at which patients consider their symptoms "satisfactory".
Outlining the reasons for their study, Turid Heiberg (Ullevål University Hospital, Oslo, Norway) and colleagues note that "a main objective for patients with RA is to reach a health state they find acceptable or satisfactory."
They continue: "The recently proposed concept of a 'patient acceptable symptom state' (PASS) implies that results from clinical studies can be expressed as proportions-that is, the proportion of patients that reach or do not reach this state."
Because exact thresholds of PASS have not been determined, Heiberg and co-workers attempted to define a threshold for the concept.
They asked 1496 RA patients (average age 54 years; 72.1% female) about their disease and related these perceptions to validated measures of disease activity. The patients studied had had RA for an average of 7.6 years.
After regular questioning conducted over 52 weeks, the researchers were able to demonstrate that the PASS was equivalent to what is usually defined as "moderate" disease activity when using the Patient Activity Scale, 28-item Disease Activity Score, Simplified Disease Activity Index, or Clinical Disease Activity Index.
Specifically, PASS was equivalent to a score of 3.56 on the Patient Activity Scale and was most closely linked to existing measures of disease activity in patients with low disease activity.
Agreement was also good in patients with moderate disease activity but disagreement appeared between PASS and other assessment tools in patients in remission.
The authors caution that, although they demonstrated the importance of patient-reported outcomes, reducing disease activity or achieving remission must remain the ultimate therapeutic goals if joint damage is to be prevented.
As long as this is taken into account, the authors say: "An intermediate state as identified through the current PASS question may be useful to report in trials and to communicate with patients."