The definition of chronic pain is pain that has persisted for over three months. The most recent Irish research into this topic – a PRIME study by the Centre for Pain Research in NUI Galway back in 2011 – found that one in three of the adults surveyed were experiencing chronic pain, with those aged over 65 most affected. While that study put the figure at one in three in Ireland, one in five is the overall figure used throughout Europe, Christina Donnelly, executive director of Chronic Pain Ireland (CPI) says.