Study Type – Preference (discrete choice experiment)
Level of Evidence 2a
What’s known on the subject? and What does the study add?
Whilst antimuscarinic treatments are widely used little work has been done to understand how patients consider the relative benefits and costs associated with their use.
This study provides data which demonstrates both the perceived value of symptom reduction and burden associated with common antimuscarinic AEs. These findings may prove useful in informing prescribing decisions.
OBJECTIVE • To examine patient preferences and strength of preferences for treatment for the various symptoms of overactive bladder and adverse events associated with the use of antimuscarinic treatments.
PATIENTS AND METHODS • A discrete choice experiment (DCE) survey was developed that detailed treatment choices in terms of attributes relating to their efficacy in reducing symptoms and the likelihood of experiencing typical adverse events. Levels for each attribute were based on a literature review, qualitative interviews and a meta-analysis of clinical trial data.
• Attributes were combined into choice sets using a fractional orthogonal design that had been folded over. Pairs of choice sets were presented to overactive bladder (OAB) patients (n= 332), who indicated which treatment alternative they preferred. Data were analysed using the conditional logit model.
RESULTS • Participants expressed the strongest preference for the avoidance of urgency incontinence episodes, followed by preference for a reduction in the experience of urinary urgency and the number of micturition episodes. The influence of the likelihood of experiencing an adverse event on treatment preference was also estimated.
• Finally, marginal rates of substitution were calculated to demonstrate the relative value of trade-offs between the various attributes.
• Treatment preferences were found to be broadly similar across two patient age groups (i.e. under 45 s and 45 and over).
CONCLUSION • The study demonstrates that individuals with OAB place significant emphasis on the prospect of reduction in symptoms. Avoidance of incontinence episodes is particularly valued and equivalent to a much greater reduction in the frequency of micturition or experience of urgency. However, even a modest increase in the likelihood of experiencing an adverse event could easily motivate a change in treatment preference.