Signal measurement strategies: are they feasible and do they offer any advantage in outcome measurement in osteoarthritis?

The applicability of a signal measurement strategy was compared with a traditional method of measuring outcome in osteoarthritis. The signal method detected statistically significant alterations in health status with small sample sizes and with a relative efficiency close to or at unity. The prevalence of deterioration in nonsignal items was low. Signal methods of measurement may provide an alternative approach to outcome measurement in osteoarthritis clinical trials.