Generating Rasch-based activity of daily living measures from the Spinal Cord Injury Longitudinal Aging Study.

STUDY DESIGN

Retrospective Longitudinal Study.

OBJECTIVES

(1) To determine whether the Spinal Cord Injury Activities of Daily Living (SCI_ADL) measure shows adequate item-level and precision psychometrics; (2) to investigate whether the SCI_ADL measure effectively detects ADL changes across time; (3) to describe self-care task(s) participants can and cannot do across time.

SETTING

Two Midwestern hospitals and 1 Southeastern specialty hospital in 1993.

METHODS

All participants were adults with traumatic SCI of at least 1-year duration at enrollment. We used 20-year (1993-2013) retrospective longitudinal data and categorized participants into three injury levels: C1-C4 (cervical; n=50), C5-C8 (n=126) and T1-S5 (thoracic, lumbar and sacral; n=168). We first examined psychometrics of the SCI_ADL with factor and Rasch analyses; then we investigated longitudinal change of SCI_ADL scores at three time points over 20 years (1993, 2003 and 2013) using generalized linear mixed modeling and post hoc analyses.

RESULTS

The SCI_ADL measure demonstrated unidimensionality, person strata of 2.9, high Cronbach's α (0.93) and fair person reliability (0.76). T1-S5 had the highest measures, following C5-C8 and C1-C4 at three time points (P<0.05). The C1-C4 and T1-S5 groups showed significant decreases from 2003 to 2013; however, none of the three groups showed significant differences from 1993 to 2003 (P<0.05).

CONCLUSIONS

The SCI_ADL measure could detect longitudinal ADL changes of the population with SCI across time. The C1-C4 group decreased the most in ADLs, indicating higher need of long-term services and rehabilitation.