Life Space Assessment in Spinal Cord Injury

Abstract

Objectives: To examine the Life Space Assessment (LSA) in persons with spinal cord injury (SCI), exploring its psychometric properties, differences between persons with cervical versus thoracolumbar injuries, and cutoff score differentiating a restricted from an unrestricted life space. Method: We conducted a test-retest reliability study in a community setting involving 50 persons with SCI (25 injured above C7, 25 injured below T1). Data were collected in 2 phone interviews approximately 9 days apart using the LSA. Results: Mean LSA scores were 66 ± 25 (n = 50): 62 ± 23 for the cervical group, and 70 ± 25 for the thoracolumbar group. Scores were not significantly different between phone interviews [t(49) = 0.379, p = .706] or between groups [t(48) = -1.214, p = .231]. Test-retest reliability intraclass correlation coefficient (ICC) was 0.876 (95% CI, 0.792-0.928). Spearman's rho correlations between the LSA and Reintegration to Normal Living Index total and subscores ranged from .509 to .538 (p < .001). LSA scores were normally distributed. The minimum detectable change was approximately 23 points. A cutoff score of 78.5 (sensitivity 76.9%, specificity 81.1%) differentiated between persons with a restricted from an unrestricted life space if equipment and personal assistance were not needed for mobility. If equipment was needed, the cutoff score was found to be 49 (sensitivity of 90%, specificity of 90%). Conclusions: The LSA is a reliable and valid measure of life space in persons with SCI and can be used to identify persons with a restricted life space who may be at increased risk of mobility disability.

Keywords: environment; locomotor activity; outcome measures; rehabilitation; spinal cord injury.

Figure 1.

Illustration of sample recruitment. AIS = American Spinal Injury Association Impairment Scale A complete, B sensory incomplete, C motor incomplete and primarily limited motor function below the lesion, D motor incomplete and primarily antigravity motor function below the lesion; CVA = cerebrovascular accident; HIPAA = Health Insurance Portability and Accountability Act; SCI = spinal cord injury; TBI = traumatic brain injury.

Figure 2.

Distribution of composite Life Space Assessment (LSA) scores (N = 50). Range of participant scores, 12 to 120. No one scored between 0 and 10.

Figure 3.

Detecting unrestricted life space in persons with spinal cord injury (SCI) who may use equipment but do not require personal assistance. The area under the receiver operating characteristic curve (AUC) illustrates the accuracy with which Life Space Assessment scores differentiate between people with restricted and unrestricted life spaces who may use equipment but not personal assistance [AUC = .954; 95% CI, (.9 to 1.0); p < .001]. A score of 49 distinguishes between restricted and unrestricted life spaces with 90% sensitivity and 90% specificity.

Figure 4.

Detecting unrestricted life space in persons with spinal cord injury (SCI) who do not use equipment or personal assistance. The area under the receiver operating characteristic curve (AUC) illustrates the accuracy with which Life Space Assessment scores differentiate between people with restricted and unrestricted life spaces when equipment and assistance are not used [AUC = .852; 95% CI, 0.746–0.958, p < .001]. A score of 78.5 distinguishes between restricted and unrestricted life spaces with 76.9% sensitivity and 81.1% specificity.