PT  - JOURNAL ARTICLE
AU  - E van der Kooi
AU  - N B Klarenbeek
AU  - M Güler-Yüksel
AU  - P J S M Kerstens
AU  - P A H M van der Lubbe
AU  - M L Westedt
AU  - S ten Wolde
AU  - T W J Huizinga
AU  - B A C Dijkmans
AU  - C F Allaart
TI  - A decrease in disease activity score (DAS) level is associated with a decrease in health assessment questionnaire (HAQ) score, independent of follow-up duration, during 5 years of tightly controlled treatment: results from the BeSt study
AID  - 10.1136/ard.2010.133132
DP  - 2011 Jan 01
TA  - Annals of the Rheumatic Diseases
PG  - 168--171
VI  - 70
IP  - 1
4099  - http://ard.bmj.com/content/70/1/168.short
4100  - http://ard.bmj.com/content/70/1/168.full
SO  - Ann Rheum Dis2011 Jan 01; 70
AB  - Objective To assess the relationship between a decrease in disease activity score (DAS) and functional ability during 5 years of DAS-steered treatment in recent-onset rheumatoid arthritis (RA) patients, taking into account absolute DAS levels and follow-up duration. Methods Data from the BeSt study were used, in which treatment was aimed at achieving DAS ≤2.4. The longitudinal relationship between 3-monthly measured DAS and health assessment questionnaire (HAQ) score was assessed using linear mixed modelling during 5 years of treatment, with DAS and HAQ 3 months earlier, change in DAS in last 3 months (delta DAS), time (log-transformed) and their interactions as determinants. Results Predictors for HAQ were: previous DAS, delta DAS, ln time, the interaction previous DAS×delta DAS, and previous HAQ. The interaction ln time×delta DAS was non-significant, indicating that the association between delta DAS and HAQ was independent of follow-up duration. A decrease from a higher DAS was associated with a smaller HAQ decrease than for a similar decrease from a lower DAS, indicating a non-linear relationship between DAS and HAQ. Conclusion At any time during 5 years of follow-up, a decrease in DAS was associated with a better functional ability. The magnitude of HAQ improvement depends on the DAS decrease and on the absolute DAS level.