TY - STAND AU - E. Herrett AU - S. Thomas AU - W. Schoonen AU - L. Smeeth AU - A. Hall BT - Br J Clin Pharmacol DO - 10.1111/j.1365-2125.2009.03537.x M1 - 1 PY - 2010 SP - 4 EP - 14 T2 - Br J Clin Pharmacol TI - Validation and validity of diagnoses in the General Practice Research Database: a systematic review VL - 69 SN - 0306-5251 ER -