The current recommendations for the conservative management of overactive bladder symptoms and detrusor overactivity, given by NICE 2012, are pelvic floor muscle training, bladder training, sacral nerve stimulation, mid-urethral tape and antimuscarinic drugs- oxybutynin, darifenacin, solifenacin, tolterodine, and tropsium. More recently, emerging evidence suggests that Botulinum toxin type A is also an effective intervention for overactive bladder and idiopathic detrusor overactivity. Although a number of meta-analyses have been published reporting pairwise comparisons of the various interventions, to date no network meta-analysis has been undertaken comparing all interventions simultaneously. OBJECTIVES: To evaluate the clinical effectiveness of drug therapy, neuromodulation, botulinum toxin, and behaviour therapy, in the prevention of overactive bladder symptoms and detrusor overactivity.  METHODS: Mixed treatment network meta-analyses for the individual, and classes (i.e. behaviour, drugs etc.), of interventions using WinBUGS. The correlations between the interventions within a class were addressed by conducting a mixed treatment network meta-analysis using a hierarchical model structure. RESULTS: Evaluation of the class of interventions, i.e. ‘lumping’ individual interventions with classes, demonstrates an increased precision in the outcome; however, categorising the interventions decreases the interpretability of the results. At the individual intervention level, the sparseness of the data decreases the precision of the estimates, but enables comparisons to be made between individual interventions.  The hierarchical model, allows both increased precision, due to the utilisation of all of the available data, whilst still allowing comparisons to be made between individual interventions both within and between classes. CONCLUSIONS: Use of a hierarchical model increases the interpretability of the mixed treatment network meta-analysis whilst maximising the precision in terms of outcome. However, defining the hierarchical structure can prove difficult in some instances, with potential comparators residing at different levels in the hierarchy.