title: How attrition impacts the internal and external validity of longitudinal research.
authors.affiliation: Division of Health and Safety, Texas A&M University, Mail Stop 4243, College Station, TX 77843-4243, USA.
authors.forename: Adam E
authors.initials: AE
authors.lastname: Barry
mesh_terms: D006266:Health Education; D006801:Humans; D008137:Longitudinal Studies; D015203:Reproducibility of Results; D012106:Research / Q000592:standards*; D018401:Sample Size; D015983:Selection Bias