Date of this Version
Objective: To assess the use of n-of-1 trials for short-term choice of drugs for osteoarthritis.
Design and setting: Evaluation of community-based patients undergoing n-of-1 trials (double-blind, cross-over comparison of celecoxib 200 or 400 mg daily vs sustained-release paracetamol 1330 mg three times daily in three pairs of two-week treatment periods with randomization of medication within pairs, with the outcomes of pain and stiffness in sites nominated by the patient, functional limitation scores, preferred medication, and side effects).
Participants: Patients with osteoarthritis (with pain for ≥1 month) severe enough to warrant consideration of long-term use of celecoxib but for whom there was doubt about its efficacy.
Main outcome measures: Changes in drug use after an n-of-1 trial.
Results: 41/59 n-of-1 trials were completed, in which for 33 (80%) the overall symptom relief by celecoxib and paracetamol was equivalent. Management after the n-of-1 trial was concordant with its result for 19 of these (13 generally using paracetamol, six celecoxib). Symptom relief for celecoxib and paracetamol was not equivalent for the remaining eight patients: celecoxib provided better relief for seven.
Conclusions: N-of-1 trials provide a rational and effective method to best choose drugs for individual with osteoarthritis. Sustained–release paracetamol is useful for most patients whose management is uncertain.