Helen MacDonald and Juan Franco are back, magnifying glasses in hand, to take a closer look at what’s happening in evidence based medicine.   In this episode: the NHS increasingly relies on physician associates to plug some of its leaks. But, what do academic studies show about the effectiveness of these newest healthcare team members? Trish Greenhalgh is professor of primary healthcare at the University of Oxford, and she tells us about her meta-study reviewing the evidence.   Meanwhile, chronic back pain can be debilitating. When it’s at its worst, patients are eager for treatments. But, what is the true effectiveness of spinal injections to alleviate pain? Jane Ballantyne is a retired professor of pain medicine. She discusses where interventions go wrong, and how new recommendations for pain management reflect the best evidence.   Finally, Helen and Juan face uncertainty. A new research methods and reporting paper published in the BMJ takes a critical look at clinical prediction models. What does the evidence tell clinicians about how to behave when outcomes can’t be exact?   Reading list: Physician associates and anaesthetic associates in UK: rapid systematic review of recent UK based research. Spinal interventions for chronic back pain Uncertainty of risk estimates from clinical prediction models: rationale, challenges, and approaches