title: Funnel plots and spine surgery: unit level and surgeon level outcome data.
authors.affiliation: Bristol Orthopaedic Spine Service, Frenchay Hospital, Bristol, BS16 1LE, UK, ian.nelson@nbt.nhs.uk.
authors.forename: Ian W
authors.initials: IW
authors.lastname: Nelson
mesh_terms: D003627:Data Interpretation, Statistical; D006801:Humans; D019637:Orthopedic Procedures / Q000592:standards* / Q000706:statistics & numerical data; D017063:Outcome Assessment, Health Care / Q000379:methods*; D061214:Patient Safety; D012042:Registries; D006113:United Kingdom