Statistical analyses
What follows represents an updated analytic approach. The original analytic plan described weekly cluster rates as the unit of analysis, while also stating that the effect of the intervention on the weekly rates would be adjusted for patient clinical and demographic factors. Recognizing that these assertions were inconsistent, we have revised the statistical model to one which uses each patient symptom score as the unit of observation. The updated analytic approach also addresses the additional primary hypotheses described above. All methods continue to be appropriate for SW-CRTs and will be performed on an intention-to-treat basis [