title: Numbers needed to treat derived from meta-analysis. Length of follow up is poorly reported.
authors.forename: R
authors.initials: R
authors.lastname: D'Amico
authors.forename: J J
authors.initials: JJ
authors.lastname: Deeks
authors.forename: D G
authors.initials: DG
authors.lastname: Altman
mesh_terms: D005500:Follow-Up Studies; D018570:Risk Assessment; D018401:Sample Size; D013997:Time Factors