Successful and unsuccessful recruitment and retainment strategies in a UK multicentre drug trial for a rare chronic pain condition which performed above target.

Introduction: Recruitment into trials in rare chronic pain conditions can be challenging, so such trials consequently are underpowered or fail.

Methods: Drawing from our experience in conducting, to date, the largest academic trial in a rare chronic pain condition, complex regional pain syndrome, we have identified recruitment and retention strategies for successful trial conduct.

Results: We present 13 strategies grouped across the categories of 'setting the recruitment rate', 'networking', 'patient information', 'trial management' and 'patient retention'.