Predictors of Missed Follow-up Visits in the National Traumatic Brain Injury Model Systems Cohort Study

Objective: To identify key variables that could predict risk of loss to follow-up (LTFU) in a nationally funded longitudinal database of persons with traumatic brain injury.

Design: Secondary analysis of a prospective longitudinal cohort study.

Setting: Traumatic Brain Injury Model System (TBIMS) Centers in the US.

Participants: A total of 17,956 TBIMS participants (N=17,956) with interview status data available were included if eligible for 1-, 2-, 5-, 10-, 15-, or 20-year follow-ups between October 31, 1989, and September 30, 2020.

Interventions: Not applicable.

Main outcome measures: Follow-up data collection completion status at years 1, 2, 5, 10, 15, and 20.

Results: Information relevant to participants' history, injury characteristics, rehabilitation stay, and patterns of follow-up across 20 years were considered using a series of logistic regression models. Overall, LTFU rates were low (consistently <20%). The most robust predictors of LTFU across models were missed earlier follow-ups and demographic factors including Hispanic ethnicity, lower education, and lack of private health insurance.

Conclusions: Efforts to retain participants in such social disadvantaged or minority groups are encouraged given their disproportionate rate of LTFU. Repeated attempts to reach participants after a previously missed assessment are beneficial because many participants that missed 1 or more follow-ups were later recovered.