%0 Journal Article %A Caroline A Sabin %A Andrew N Phillips %T Cohort studies in sexual health %D 2001 %R 10.1136/sti.77.3.174 %J Sexually Transmitted Infections %P 174-178 %V 77 %N 3 %U https://sti.bmj.com/content/sextrans/77/3/174.full.pdf