Relationship between independence in activities of daily living at discharge and physical activity at admission of older postoperative hip fracture rehabilitation inpatients: A retrospective case-control study.

BACKGROUND AND PURPOSE: Hip fractures are associated with a reduction in activities of daily living (ADL) and require long-term care. The physical activity of patients with hip fractures is temporarily impaired immediately after surgery, causing difficulty in the measurement of physical activities at the time of rehabilitation admission. This study examined the relationship between ADL at discharge and light- and moderate-intensity physical activity at the time of rehabilitation admission by determining a cut-off value predicting ADL independence.

METHODS: This retrospective case control study analyzed 43 postoperative hip fracture patients aged ≥65 years admitting into inpatient rehabilitation. ADL at discharge was assessed using the Functional Independent Measure motor items (FIM-m). The duration of physical activity at the time of rehabilitation admission was measured using an activity tracker equipped with an accelerometer. Prehospital frailty was evaluated using Clinical Frailty Scale. The relationship between these variables was examined using Spearman's product-moment correlation coefficient. Differences in physical activity between patients requiring and not requiring assistance with ADLs were examined using the analysis of covariance. A receiver operating characteristic curve of the need for ADL assistance at discharge was constructed from the duration of physical activity.

RESULTS: The duration of physical activity at the time of rehabilitation admission was related to FIM-m at discharge. The cut-off value of the duration of physical activity for predicting the need for ADL assistance at discharge was 135 s, with a sensitivity of 83.3% and specificity of 68.4% (area under the curve: 0.76).

DISCUSSION: The duration of physical activity at the time of rehabilitation admission may be a factor that can quantitatively predict the risk of requiring assistance with ADLs at discharge in older hip fracture patients. The duration of light-and-moderate intensity physical activity may be a component of multidisciplinary inpatient rehabilitation to improve patients' ADL.