Laraine Winter, Helene Moriarty, Keith M Robinson, Benjamin E. Leiby, Krista Schmidt, Christina R Whitehouse, R. Swanson
{"title":"Age Suppresses the Association Between Traumatic Brain Injury Severity and Functional Outcomes: A Study Using the NIDILRR TBIMS Dataset.","authors":"Laraine Winter, Helene Moriarty, Keith M Robinson, Benjamin E. Leiby, Krista Schmidt, Christina R Whitehouse, R. Swanson","doi":"10.1097/HTR.0000000000000955","DOIUrl":null,"url":null,"abstract":"OBJECTIVES\nRecovery from traumatic brain injury (TBI) is extremely difficult to predict, with TBI severity usually demonstrating weak predictive validity for functional or other outcomes. A possible explanation may lie in the statistical phenomenon called suppression, according to which a third variable masks the true association between predictor and outcome, making it appear weaker than it actually is. Age at injury is a strong candidate as a suppressor because of its well-established main and moderating effects on TBI outcomes. We tested age at injury as a possible suppressor in the predictive chain of effects between TBI severity and functional disability, up to 10 years post-TBI.\n\n\nSETTING\nFollow-up interviews were conducted during telephone interviews.\n\n\nPARTICIPANTS\nWe used data from the 2020 NDILRR Model Systems National Dataset for 4 successive follow-up interviews: year 1 (n = 10,734), year 2 (n = 9174), year 5 (n = 6,201), and year 10 (n = 3027).\n\n\nDESIGN\nSuccessive cross-sectional multiple regression analyses.\n\n\nMAIN MEASURES\nInjury severity was operationalized using a categorical variable representing duration of posttrauma amnesia. The Glasgow Outcomes Scale-Extended (GOS-E) operationally defined functioning. Sociodemographic characteristics having significant bivariate correlations with GOS-E were included.\n\n\nRESULTS\nEntry of age at injury into the regression models significantly increases the association between TBI severity and functioning up to 10 years post-TBI.\n\n\nCONCLUSIONS\nAge at injury is a suppressor variable, masking the true effect of injury severity on functional outcomes. Identifying the mediators of this suppression effect is an important direction for TBI rehabilitation research.","PeriodicalId":519229,"journal":{"name":"The Journal of Head Trauma Rehabilitation","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Journal of Head Trauma Rehabilitation","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1097/HTR.0000000000000955","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
OBJECTIVES
Recovery from traumatic brain injury (TBI) is extremely difficult to predict, with TBI severity usually demonstrating weak predictive validity for functional or other outcomes. A possible explanation may lie in the statistical phenomenon called suppression, according to which a third variable masks the true association between predictor and outcome, making it appear weaker than it actually is. Age at injury is a strong candidate as a suppressor because of its well-established main and moderating effects on TBI outcomes. We tested age at injury as a possible suppressor in the predictive chain of effects between TBI severity and functional disability, up to 10 years post-TBI.
SETTING
Follow-up interviews were conducted during telephone interviews.
PARTICIPANTS
We used data from the 2020 NDILRR Model Systems National Dataset for 4 successive follow-up interviews: year 1 (n = 10,734), year 2 (n = 9174), year 5 (n = 6,201), and year 10 (n = 3027).
DESIGN
Successive cross-sectional multiple regression analyses.
MAIN MEASURES
Injury severity was operationalized using a categorical variable representing duration of posttrauma amnesia. The Glasgow Outcomes Scale-Extended (GOS-E) operationally defined functioning. Sociodemographic characteristics having significant bivariate correlations with GOS-E were included.
RESULTS
Entry of age at injury into the regression models significantly increases the association between TBI severity and functioning up to 10 years post-TBI.
CONCLUSIONS
Age at injury is a suppressor variable, masking the true effect of injury severity on functional outcomes. Identifying the mediators of this suppression effect is an important direction for TBI rehabilitation research.