Jim Al-Khalili talks to the pioneering health services researcher, Iain Chalmers, who was one of the founders of the Cochrane Collaboration. Once described by one writer as 'The Maverick Master of Medical Evidence'. Iain Chalmers trained as a doctor, eventually specialising in obstetrics. But early in his career, he started to question the basis of everything he was trained to do and this set him on a very different path: to champion treatments based on the best available evidence, first in his own field and then across healthcare. It's a journey that has at times challenged the foundations of medical practice. In 1992, he was appointed Director of the Cochrane Centre, which led to the foundation of the Cochrane Collaboration, dedicated to ensuring that patients, doctors and researchers have access to unbiased information about the effectiveness of healthcare interventions, across the world. Iain wants to reduce uncertainty in medicine so that patients can make sensible choices about their care. There are now 30,000 Cochrane members world wide, from Brazil to Belgium, Spain to South Africa. He's been hugely influential both within medicine but across all areas of social policy and the inspiration for a generation of evidence-based, sceptical enquirers such as Ben Goldacre. A frequent irritant of the medical establishment Iain become one of them when he was knighted for services to healthcare in 2000.Having spent his career trying to change the mindset of the medical community from the inside, he's now pushing from the outside, arguing that patients' concerns should drive the medical research agenda. Producer: Rami Tzabar.