RT Journal Article SR Electronic T1 Authors' response JF British Journal of General Practice JO Br J Gen Pract FD British Journal of General Practice SP 292 OP 293 DO 10.3399/bjgp11X567199 VO 61 IS 585 A1 Sarah Purdy A1 David de Berker YR 2011 UL http://bjgp.org/content/61/585/292.2.abstract AB