Statistical analysis
SECONDARY
The data analysis plan is described in the The baseline demographics and clinical characteristics of general practice clusters and individual participants were reported. For the continuous variables (eg, age), either mean and SD was presented or median and IQR depending on the distribution of the data. The number of observations used in each calculation was shown alongside the summaries. For the categorical variables (eg, sex), the number and percentage of participants in each of the categories and the total number of observations were presented. A comparison of the responses, overall scoring and subgroup numbers was undertaken. All baseline summaries were presented and reported for each intervention arm and in total. Consolidated standards of reporting trials (CONSORT) guidelines generally do not recommend statistical significance testing of baseline imbalances between the arms.The primary outcome was analysed using a χSimilar to the analysis of the primary outcome, the secondary outcomes were analysed using a χSubgroup exploratory analysis to identify the prognostic factors for successful withdrawal for the primary and secondary outcomes was conducted using univariate analysis. The optimal cut-off value for the prognostic factor was calculated using receiver operator characteristic (ROC) curve analysis. All analyses were performed using JMP V.11.0 (SAS Institute).