The severity or algofunctional indices for hip and knee osteoarthritis
(OA) have been used in Europe for about 10 years. They were validated
, then published between 1982 and 1987(1,2) . They are useful mainly a
s outcome measures in OA trials, and also for appraising the severity
of patient function: a score above 11-12 points after appropriate trea
tment indicates surgery. Most patients recruited in OA trials have a s
core of 9-11 (SD 23 to 3.8), decreasing about 30 to 40% with the activ
e drug. The effect size reaches 1.3 to 1.8. The indices have 2 advanta
ges: they are structured separately for hip and for knee OA and the sa
me instrument serves as a measure of severity (disability scale) and a
s an outcome measurement tool in trials.