1. Northern Deanery, Postgraduate Institute for Medicine and Dentistry, 10/12 Framlington Place, Newcastle upon Tyne NE2 4AB, UK.
2. Sunderland Royal Hospital, Kayll Road, Sunderland SR4 7TP, UK.
3. Cumberland Infirmary, Newtown Road, Carlisle, Cumbria CA2 7HY, UK.