Initial analyses will be exploratory to compare symptom profiles between people who respond to treatment and treatment non-responders. Treatment responders will be categorised by the OMERACT-OARSI responder criteria. Categorical variables will be analysed using chi-square tests. Multivariate analysis of variance (MANOVA) will be used to compare continuous normally distributed variables between responders and non-responders. The Kruskal-Wallis test will be used for comparison of variables that are not normally distributed. A p value of less than 0.05 will be considered significant.