Functional Outcomes Over the First Year After Moderate to Severe Traumatic Brain Injury in the Prospective, Longitudinal TRACK-TBI Study

Abstract

IMPORTANCEModerate to severe traumatic brain injury (msTBI) is a major cause of death and disability in the US and worldwide. Few studies have enabled prospective, longitudinal outcome data collection from the acute to chronic phases of recovery after msTBI. OBJECTIVE To prospectively assess outcomes in major areas of life function at 2 weeks and 3, 6, and 12 months after msTBI. DESIGN, SETTING, AND PARTICIPANTS This cohort study, as part of the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study, was conducted at 18 level 1 trauma centers in the US from February 2014 to August 2018 and prospectively assessed longitudinal outcomes, with follow-up to 12 months postinjury. Participants were patients with msTBI (Glasgow Coma Scale scores 3-12) extracted from a larger group of patients with mild, moderate, or severe TBI who were enrolled in TRACK-TBI. Data analysis took place from October 2019 to April 2021. EXPOSURES Moderate or severe TBI. MAIN OUTCOMES AND MEASURESThe Glasgow Outcome Scale-Extended (GOSE) and Disability Rating Scale (DRS) were used to assess global functional status 2 weeks and 3, 6, and 12 months postinjury. Scores on the GOSE were dichotomized to determine favorable (scores 4-8) vs unfavorable (scores 1-3) outcomes. Neurocognitive testing and patient reported outcomes at 12 months postinjury were analyzed. RESULTS A total of 484 eligible patients were included from the 2679 individuals in the TRACK-TBI study. Participants with severe TBI (n = 362; 283 men [78.2%]; median [interquartile range] age, 35.5 [25-53] years) and moderate TBI (n = 122; 98 men [80.3%]; median [interquartile range] age, 38 [25-53] years) were comparable on demographic and premorbid variables. At 2 weeks postinjury, 36 of 290 participants with severe TBI (12.4%) and 38 of 93 participants with moderate TBI (41%) had favorable outcomes (GOSE scores 4-8); 301 of 322 in the severe TBI group (93.5%) and 81 of 103 in the moderate TBI group (78.6%) had moderate disability or worse on the DRS (total score Ն4). By 12 months postinjury, 142 of 271 with severe TBI (52.4%) and 54 of 72 with moderate TBI (75%) achieved favorable outcomes. Nearly 1 in 5 participants with severe TBI (52 of 270 [19.3%]) and 1 in 3 with moderate TBI (23 of 71 [32%]) reported no disability (DRS score 0) at 12 months. Among participants in a vegetative state at 2 weeks, 62 of 79 (78%) regained consciousness and 14 of 56 with available data (25%) regained orientation by 12 months.CONCLUSIONS AND RELEVANCE In this study, patients with msTBI frequently demonstrated major functional gains, including recovery of independence, between 2 weeks and 12 months postinjury. Severe impairment in the short term did not portend poor outcomes in a substantial minority of patients with msTBI. When discussing prognosis during the first 2 weeks after injury, clinicians should be particularly cautious about making early, definitive prognostic statements suggesting poor outcomes and withdrawal of life-sustaining treatment in patients with msTBI.

Comparison of common outcome measures for assessing independence in patients diagnosed with disorders of consciousness: A Traumatic Brain Injury Model Systems Study

“…In contrast to the GOSE, the distribution of DRS scores skewed towards the milder end of the scale, suggesting a greater potential for determining meaningful functional differences between patients with DoC after TBI. However, like the GOSE ≤3 category, we found that common DRS total score groupings reported in prior studies (e.g., Moderate and Moderately-Severe) 2, 8, 37 , also spanned a wide range of FIM total scores. Although there is less precedent for dichotomizing the DRS, we found that a cut-point of at least Severe Disability (DRS ≥12) was a specific, but insensitive marker of FIM-dependency.…”

“…Our findings highlight the wide range of functional impairment within dichotomized GOSE and DRS categories and demonstrate fundamental differences in the calibration of these outcome scales. Most participants in this study achieved a 1-year GOSE score of 3 (Lower-Severe Disability), just one category above “Vegetative State” and typically considered an ‘unfavorable’ outcome 2, 30-35 . GOSE ≤3 was a highly sensitive but non-specific marker for FIM-dependency.…”

“…Though the GOSE can be analyzed ordinally 29 , it is often dichotomized into ‘favorable’ and ‘unfavorable’ outcomes, with an ‘unfavorable’ cut-point set at ≤3 (Lower Severe Disability, e.g. cannot be left unsupervised in the home for more than 8 hours) 2, 30-32 or ≤4 (Upper Severe Disability, e.g. can be left unsupervised in the home for more than 8 hours, but dependent outside the home) 33-35 .…”

“…The eight item scores are then summed to generate a total score of 0 (least disabled) to 30 (dead) 8 . Prior observational and interventional studies 2, 37 have categorized DRS total scores into ad-hoc groupings such as: None (0), Mild (1), Partial (2-3), Moderate (4-6), Moderately-severe (7-11), Severe (12-16), Extremely severe (17-21), Vegetative state (22 -24), Extreme vegetative state (25-29) 8 . We evaluated the performance of the Severe Disability cutpoint (scores ≥ 12), as well as a data-driven optimal cut-point for classifying FIM-dependency.…”

Current Trends in Mild Traumatic Brain Injury

“…Their efforts have translated into decreased TBI mortality rates over the past decade in the United States [ 3 ]. Recently it was reported 75% of moderate TBI patients achieve GOSE scores ≥4 at 12 months, and 57% of severe TBI patients achieve GOSE scores ≥5 at six months [ 4 , 5 ]. For clinicians, the Brain Trauma Foundation Guidelines for the Management of Severe TBI is an invaluable resource [ 6 ].…”