title: A technique for summarizing longitudinal data.
abstract: Many studies collect longitudinal data but do not use them efficiently. We propose a technique for reducing a set of longitudinal data into four common summary statistics together with time. These statistics can be used in place of the raw data in further analyses, for example in a regression analysis. Instead of arbitrarily choosing the summary statistics, we derive them mathematically, thus justifying their use. This simplifies the subsequent analyses, and also improves the interpretation of the results. An example from the Framingham Heart Study illustrates the procedure.
authors.affiliation: Department of Mathematics, Olivet Nazarene University, Kankakee, IL 60901-0592.
authors.forename: D K
authors.initials: DK
authors.lastname: Hathaway
authors.forename: R B
authors.initials: RB
authors.lastname: D'Agostino
mesh_terms: D015982:Bias; D016009:Chi-Square Distribution; D003327:Coronary Disease / Q000453:epidemiology; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008433:Mathematics; D011237:Predictive Value of Tests; D012307:Risk Factors; D013997:Time Factors