Radiographic progression in rheumatoid arthritis: a long-term prospective study of 109 patients.
OBJECTIVE
To investigate the long-term radiographic course as a mathematical function of disease duration in individual patients and in a group of patients with rheumatoid arthritis (RA).


METHODS
In 109 patients with RA, radiographic examinations of 46 diarthrodial joints were performed at regular intervals of 1-3 years, for up to 30 years after disease onset.


RESULTS
Five main types of progression were identified: 1) a rare type (<1%), with no radiographic progression at all; 2) a type with a slow or moderate onset, but an increasing progression rate (9% exponential growth type and 30% linear type); 3) a type with a moderate-to-fast onset and a stable progression rate (the square-root type; 11%); 4) a type with a fast onset, but a later decreasing progression rate (the first-order kinetics type, 30%); and 5) a type characterized by slow onset, then acceleration and later deceleration (the sigmoid type, 20%).


CONCLUSIONS
The progression of radiographic damage in RA followed mathematical functions of time. The identification of progression type may be used in the prediction of outcome in patients with RA.
Graudal
N A
NA
Aarhus University Hospital, Denmark.
Jurik
A G
AG
de Carvalho
A
A
Graudal
H K
HK
D000293:Adolescent; D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging*; D001175:Arthrography; D018450:Disease Progression; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D011379:Prognosis; D011446:Prospective Studies; D012044:Regression Analysis; D016019:Survival Analysis; D013997:Time Factors