Reliability and Validity of a Japanese Version of Life-Space Assessment in Institutionalized Settings

Purpose A reduction in life space (LS) is associated with a negative impact on medical and functional status during hospitalization, with potential consequences after discharge. A validated version of an evaluation tool for assessing LS in Japanese individuals in an institutionalized setting is lacking. This study developed and validated a Japanese version of the Life-Space Assessment in Institutionalized Settings (LSA-IS-J). Material and Methods The LSA-IS-J was developed using a specified process. This study included 30 inpatients admitted to the rehabilitation ward. The Timed Up and Go Test, Berg Balance Scale scores, 10-meter walking time, Functional Independence Measure, and Falls Efficacy Scale-International were used to assess construct validity. For test-retest reliability, the same assessor evaluated the LSA-IS-J within two days. Correlation coefficients were calculated to determine the construct validity. Results The mean LSA-IS-J total score mean was 37.7 (standard deviation: 7.4), with skewness of -0.17 and kurtosis of -1.39. No ceiling or floor effects are observed. The test-retest reliability was excellent for the total and subtests, with intraclass correlations ranging from 0.78 to 0.99. The LSA-IS-J showed significant correlations with almost all variables related to motor status and concerns about falling, indicating high construct validity. In contrast, more generic variables were not significantly associated. Conclusions The LSA-IS-J demonstrated broad feasibility for assessing LS without ceiling or floor effects among patients undergoing ward-based rehabilitation. The LSA-IS-J also demonstrated excellent test-retest reliability and adequate construct validity for constructs with a high impact on LS.