The study was conducted between 1 December 2000 and 29 February 2004 and included people living in the Thames region, southern Scotland, Trent, the West Midlands and West Yorkshire.
966 people with glioma brain tumours (cases) and 1716 healthy volunteers (controls) were interviewed about their previous mobile phone use history including how long they had used mobile phones, the number and duration of the calls they made and what make and model of phone they had used.