USE OF BEST-WORST SCALING TO ASSESS PATIENT PREFERENCES FOR REFRACTORY OVERACTIVE BLADDER TREATMENTS

Purpose: Current treatments for refractory overactive bladder (OAB) differ considerably: sacral neuromodulation (SNM) involves implanting a device in the buttock; onabotulinumtoxinA involves injections into the bladder; and percutaneous tibial nerve stimulation (PTNS) involves inserting a needle into the ankle. We sought to use best-worst scaling (BWS) to assess patient preferences for differentiating attributes of these treatments and compare direct preference elicitation with the BWS scores versus traditional Likert responses. 

Methods: Qualitative interviews with OAB patients and clinicians informed the development of an online survey incorporating several stated-preference methods. Best-worst scaling (Case 1) was used to assess 13 treatment features. Across 13 tasks presenting subsets of attributes, respondents identified the best and worst. A score ranging from -1.0 (worst) to 1.0 (best) were calculated based on the rates each attribute was chosen. Attitudes toward the attributes were assessed via like/dislike Likert scales, and patients were asked their percentage likelihood (0-100%) of trying each treatment, based on standardized treatment descriptions.    

Results: 245 OAB patients (118 US, 127 UK) completed the survey (79% female; mean age of 50 + 7.8.  ‘Lasting improvement’ (0.82), and ‘minimal side effects’ (0.67)’ were rated most favorably, and ‘implant complications’ (-0.65), and ‘Be willing to self-catheterize’ (-0.53) were rated worst. The percentage likelihood estimates for trying one of the three treatments were significantly correlated with the BWS scores.  Specifically, the likelihood of trying SNM was correlated with ‘implanted device’ and ‘sends signals’, and negatively correlated with ‘repeated visits’, ‘needle in ankle’, and ‘minimal side effects’.  The likelihood of trying onabotulinumtoxinA was correlated with ‘Botox (botulinum toxin) treatment’, ‘self-catheterize’, ‘treatment via urethra’, and ‘minor procedure’, and was negatively correlated with ‘needle in ankle’, ‘implant complications’, ‘repeated visits’, and ‘implanted device’.   The likelihood of trying PTNS was correlated with ‘needle in ankle’ and ‘sends signals’, and was negatively correlated with ‘minor procedure’ and ‘Botox (botulinum toxin) treatment’.  In contrast, all the attribute like/dislike Likert scores only were positively correlated with willingness to try treatment, thus disliking attributes was not associated with willingness to try an alternative treatment. 

Conclusions: BWS was successful in assessing the magnitude of patient preferences for attributes associated with different refractory OAB therapies.  Compared to Likert items, BWS may be more sensitive in capturing both positive and negative attributes driving treatment selection.