Add no noticeable value to the benefits of existing care for chronic conditions Clinical trialists, interested in ensuring that their interventions are effective in the real world of clinical practice, have long called for study designs—termed practical, pragmatic, or effectiveness—that reflect practice as closely as possible.1 These practical trials are particularly important in health services research, which can involve apparently effective interventions that are resource intensive and implemented by charismatic enthusiasts. Such interventions are likely to fail when introduced into settings with fewer resources by doctors preoccupied with the considerable stresses of everyday practice. In a linked paper by Kennedy and colleagues (doi:10.1136/bmj.f2882), we learn that effective interventions in health services are often not feasible and—as revealed by practical trials—feasible interventions are often not effective.2 In a cluster randomised controlled trial, Kennedy and colleagues investigated whether self management interventions targeting care providers could improve outcomes over 12 months in patients with diabetes, chronic obstructive pulmonary diseases, and …