Institutional members access full text with Ovid®

Share this article on:

Factors Associated With Rehabilitation Outcomes After Traumatic Brain Injury: Comparing Functional Outcomes Between TBIMS Centers Using Hierarchical Linear Modeling

Dahdah, Marie N. PhD; Hofmann, Melissa PhD; Pretz, Christopher PhD; An, Viktoriya MS; Barnes, Sunni A. PhD; Bennett, Monica PhD; Dreer, Laura E. PhD; Bergquist, Thomas PhD; Shafi, Shahid MD, MPH

The Journal of Head Trauma Rehabilitation: July/August 2017 - Volume 32 - Issue 4 - p E1–E10
doi: 10.1097/HTR.0000000000000270
Focus on Clinical Research and Practice

Objective: To examine differences in patient outcomes across Traumatic Brain Injury Model Systems (TBIMS) rehabilitation centers and factors that influence these differences using hierarchical linear modeling (HLM).

Setting: Sixteen TBIMS centers.

Participants: A total of 2056 individuals 16 years or older with moderate to severe traumatic brain injury (TBI) who received inpatient rehabilitation.

Design: Multicenter observational cohort study using HLM to analyze prospectively collected data.

Main Outcome Measures: Functional Independence Measure and Disability Rating Scale total scores at discharge and 1 year post-TBI.

Results: Duration of posttraumatic amnesia (PTA) demonstrated a significant inverse relationship with functional outcomes. However, the magnitude of this relationship (change in functional status for each additional day in PTA) varied among centers. Functional status at discharge from rehabilitation and at 1 year post-TBI could be predicted using the slope and intercept of each TBIMS center for the duration of PTA, by comparing it against the average slope and intercept.

Conclusions: HLM demonstrated center effect due to variability in the relationship between PTA and functional outcomes of patients. This variability is not accounted for in traditional linear regression modeling. Future studies examining variations in patient outcomes between centers should utilize HLM to measure the impact of additional factors that influence patient rehabilitation functional outcomes.

Baylor Institute for Rehabilitation, Dallas, Texas (Dr Dahdah); Baylor Regional Medical Center Plano, Plano, Texas (Dr Dahdah); North Texas TBIMS, Baylor Institute for Rehabilitation, Dallas (Drs Dahdah and Shafi); National Data & Statistical Center/Craig Hospital, Englewood, Colorado (Drs Hofmann, Pretz, and An); Office of the Chief Quality Officer, Baylor Scott & White Health, Dallas, Texas (Drs Barnes, Bennett, and Shafi); University of Alabama at Birmingham Traumatic Brain Injury Model System (Dr Dreer); and Department of Psychiatry and Psychology and Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, Minnesota (Dr Bergquist).

Corresponding Author: Marie N. Dahdah, PhD, Baylor Institute for Rehabilitation, 909 N. Washington Ave, Ste 232, Dallas, TX 75246 (

The contents of this article were developed under a grant from the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR grant no. 90DP0045-01-0). NIDILRR is a Center within the Administration for Community Living (ACL), Department of Health and Human Services (HHS). The project was also supported by the Ginger Murchison Foundation.

The contents of this article do not necessarily represent the policy of NIDILRR, ACL, HHS, and you should not assume endorsement by the Federal Government.

The authors declare no conflicts of interest.

Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved.