Bj. Harrison et al., INFLAMMATORY POLYARTHRITIS IN THE COMMUNITY IS NOT A BENIGN DISEASE -PREDICTING FUNCTIONAL DISABILITY ONE-YEAR AFTER PRESENTATION, Journal of rheumatology, 23(8), 1996, pp. 1326-1331
Objective. To predict which patients with early inflammatory polyarthr
itis presenting to primary care will be functionally disabled one year
after presentation, in order to inform treatment and referral decisio
ns. Methods. The study population consisted of 381 patients notified t
o the Norfolk Arthritis Register, a primary care based inception cohor
t of patients with inflammatory polyarthritis. Patients were regarded
as functionally disabled if they had a Health Assessment Questionnaire
(HAQ) score of one or more. Clinical, laboratory, and demographic var
iables easily measured at baseline were analyzed for their ability to
predict future disability. Recursive partitioning was used to create a
simple decision tree to predict those patients who would be disabled
at one year. A logistic regression model was generated on a sample of
277 patients and tested on an independent sample of 104 patients, This
was compared with other models, one of which consisted of the 1987 AR
A criteria. Results, 112 (29%) patients had a HAQ score of at least 1
at one year. The strongest predictors of future disability were a high
baseline HAQ, large joint involvement, female sex, and longer disease
duration. The decision tree predicted disability accurately in 67% of
patients. Conclusion. It is possible to predict functional outcome at
one year among patients with early inflammatory polyarthritis present
ing to primary care using simple clinical variables measured at baseli
ne. Satisfying the 1987 ARA criteria could not be used to predict futu
re disability.