How Do Intensity and Duration of Rehabilitation Services Affect Outcomes from Severe Traumatic Brain Injury? A Natural Experiment Comparing Healthcare Delivery Systems in Two Developed Nations

OBJECTIVE: Determine effects of inpatient and outpatient treatment intensity on functional and emotional well-being outcomes at 1 year post severe traumatic brain injury (TBI).

DESIGN: Prospective, quasi-experimental study comparing outcomes in a US TBI treatment center with those in a Denmark (DK) center providing significantly greater intensity and duration of rehabilitation.

SETTING: Inpatient and outpatient TBI rehabilitation.

PARTICIPANTS: 274 persons with severe traumatic brain injury.

INTERVENTIONS: Inpatient rehabilitation interventions were counted daily by discipline. Outpatient treatments were estimated per discipline using a structured interview administered to patients and/ or caregivers at 12 months.

MAIN OUTCOME MEASURES: FIM, Glasgow Outcome Scale- Extended, Disability Rating Scale, Participation Assessment with Recombined Tools-Objective, Perceived Quality of Life, SF-12, Brief Symptom Inventory-18 item version.

RESULTS: Despite identical inclusion criteria, patient severity on admission was greater at the DK site. After adjustment for patient/ injury characteristics, there were no site differences in either functional or emotional outcome at 12 months. Significantly more inpatient + outpatient treatment was administered to DK patients than to those in the US. For functional but not emotional treatments, more severely impaired patients received higher doses. One-year outcomes were predicted by admission severity, age, employment, and other baseline characteristics.

CONCLUSIONS: Contrary to expectation, DK patients who received significantly more rehabilitation services during the year following severe TBI did not differ in outcome from their less intensively treated US counterparts, after adjusting for initial severity. The negative association of functional treatment dose with extent of early disability suggests that dose was driven by unmeasured factors reflecting need for services. Improved measures of injury-related factors driving treatment allocation are needed to model the independent effects of treatment on outcomes.