title: Discrepancies in Natsal--authors' reply.
authors.affiliation: Centre for Sexual Health & HIV Research, Research Department of Infection & Population Health, University College London, London WC1E 6JB, UK. Electronic address: c.mercer@ucl.ac.uk.
authors.forename: Catherine H
authors.initials: CH
authors.lastname: Mercer
authors.affiliation: Centre for Sexual Health & HIV Research, Research Department of Infection & Population Health, University College London, London WC1E 6JB, UK.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Johnson
mesh_terms: D001294:Attitude to Health; D005260:Female; D006306:Health Surveys; D006801:Humans; D008019:Life Style; D008297:Male; D060728:Reproductive Health; D012725:Sexual Behavior / Q000706:statistics & numerical data*