Effect of body mass index on functional outcome in patients with traumatic brain injury

Mobility and self-care outcomes in patients with a bariatric comorbidity during inpatient rehabilitation

OBJECTIVE

First, we describe the characteristics and functional outcomes of obese and bariatric patients in an inpatient rehabilitation facility (IRF). Second, we assessed differences in functional outcomes for bariatric, obese, and standard weight body mass index (BMI) groups. Third, we explored whether these characteristics differ between time periods and diagnostic groups.

DESIGN

A retrospective study comparing electronic medical record data collected in 2016 and 2018, using a repeated cross-sectional cohort design.

SETTING

IRF.

PARTICIPANTS

Individuals ≥18 years of age diagnosed with brain injury, medical complexity, general neurology, orthopedic, spinal cord injury (SCI), and stroke. Participants grouped as standard (BMI <30 kg/m2), obese (BMI 30-39 kg/m2), and bariatric (BMI ≥40 kg/m2) weights. (N = 2015 in 2016, N = 2768 in 2018.) INTERVENTIONS: Patients received standard inpatient rehabilitation. In 2018, clinicians had access to new weight-appropriate equipment.

MAIN OUTCOME MEASURES

Discharge destination; length of stay (LOS) by BMI group and medical diagnoses; item-specific functional independence measure (FIM) change scores.

RESULTS

Sixty-four percent to 67% of all BMI groups achieved a home discharge. The bariatric BMI group had a longer LOS (21 days) than the standard or obese groups. There was a significant interaction in a linear regression analysis between diagnosis and LOS, where LOS was longer in medically complex patients with bariatric BMI (19.3 days compared to 16.1 days) but shorter in bariatric patients with SCI (20.6 days) compared to standard weight patients (26.2 days). In 2018, the bariatric BMI group had greater average FIM change scores for bathing, lower body dressing, toilet transfers, and bed transfers.

CONCLUSIONS

Patient BMI is associated with LOS in the IRF, although affected by diagnosis. Patients with higher BMIs can make changes in specific individual motor FIM items. For patients with bariatric BMIs, FIM change scores were higher in 2018, possibly due to the use of equipment and facilities designed for higher weight capacities.

Rehabilitation Length of Stay, Body Mass Index, and Functional Improvement among Adults with Traumatic Spinal Cord Injury

OBJECTIVE

Examine the modifying effect of body mass index (BMI) on the association between rehabilitation length of stay (LOS), severity of injury, and motor FIM® (mFIM) improvement in patients with traumatic spinal cord injury (TSCI).

DESIGN

Retrospective cohort study.

SETTING

Seventeen SCI Model Systems (SCIMS) centers in the United States.

PARTICIPANTS

3,413 patients who has a TSCI admitted to an SCIMS between October 2011 and August 2018.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The mFIM (12 items) improvement by discharge. Four rehabilitation LOS groups split by quartiles were created for each neurologic severity of injury group (C1-C4 level with American Spinal Injury Impairment Scale [AIS) ABC, C5-C8 AIS ABC, T1-S3 AIS ABC, and AIS DE). The interrelationship among rehabilitation LOS, BMI, and mFIM improvement were examined using multivariate linear regressions. A stratified analysis was performed to examine the association between rehabilitation LOS and mFIM improvement by BMI status (under or normal weight, overweight, and obese) and neurologic groups.

RESULTS

1099 (32.2%) and 821 (24.1%) patients were overweight and obese, respectively. Patients with obesity had less improvement in mFIM than those who were under or normal weight (unit of mFIM improvement =-3.71). After stratifying by BMI status, among obese patients, those with the longest rehabilitation LOS showed greater improvement in mFIM than those in the shortest LOS (unit of mFIM improvement =4.78).

CONCLUSIONS

Longer inpatient rehabilitation LOS may benefit patients with TSCI by increasing mFIM improvement by discharge. Obesity is negatively associated with mFIM improvement.