title: Analysis of Longitudinal Outcome Data with Missing Values in Total Knee Arthroplasty.
abstract: We sought to determine the influence of missing data on the statistical results, and to determine which statistical method is most appropriate for the analysis of longitudinal outcome data of TKA with missing values among repeated measures ANOVA, generalized estimating equation (GEE) and mixed effects model repeated measures (MMRM). Data sets with missing values were generated with different proportion of missing data, sample size and missing-data generation mechanism. Each data set was analyzed with three statistical methods. The influence of missing data was greater with higher proportion of missing data and smaller sample size. MMRM tended to show least changes in the statistics. When missing values were generated by 'missing not at random' mechanism, no statistical methods could fully avoid deviations in the results.
authors.affiliation: Joint Reconstruction Center, Seoul National University Bundang Hospital, Seongnam-si, South Korea.
authors.forename: Yeon Gwi
authors.initials: YG
authors.lastname: Kang
authors.affiliation: Department of Statistics, Dan Kook University, Yongin-si, South Korea.
authors.forename: Jang Taek
authors.initials: JT
authors.lastname: Lee
authors.affiliation: Joint Reconstruction Center, Seoul National University Bundang Hospital, Seongnam-si, South Korea.
authors.forename: Jong Yeal
authors.initials: JY
authors.lastname: Kang
authors.affiliation: Department of Psychology, Princeton University, Princeton, New Jersey.
authors.forename: Ga Hye
authors.initials: GH
authors.lastname: Kim
authors.affiliation: Joint Reconstruction Center, Seoul National University Bundang Hospital, Seongnam-si, South Korea.
authors.forename: Tae Kyun
authors.initials: TK
authors.lastname: Kim
mesh_terms: D000368:Aged; D000465:Algorithms; D000704:Analysis of Variance; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D003625:Data Collection; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D010003:Osteoarthritis / Q000601:surgery; D016059:Range of Motion, Articular; D012107:Research Design; D012189:Retrospective Studies; D018401:Sample Size; D011795:Surveys and Questionnaires
keywords: generalized estimating equation; missing data; mixed model repeated measures; repeated measures ANOVA; total knee arthroplasty