Related Experiment Video
Updated: Dec 26, 2025
Using a Real-Time Locating System to Measure Walking Activity Associated with Wandering Behaviors Among Institutionalized Older Adults
Published on: February 8, 2019
Measuring Mobility in Low Functioning Hospital Patients: An AM-PAC Replenishment Project
Daniel L Young1, Sowmya Kumble2, Carmen Capo-Lugo3
1Department of Physical Therapy, University of Nevada Las Vegas, Las Vegas, Nevada; Outcomes After Critical Illness and Surgery (OACIS) Research Group, Johns Hopkins University, Baltimore, Maryland; Department of Physical Medicine and Rehabilitation, Johns Hopkins University, Baltimore, Maryland.
Researchers expanded the Activity Measure for Post-Acute Care (AM-PAC) by adding two new items. This enhancement improved mobility measurement for patients with the lowest function levels, reducing measurement floors and increasing sensitivity.
Area of Science:
- Rehabilitation Medicine
- Health Measurement
- Geriatric Care
Background:
- The Activity Measure for Post-Acute Care (AM-PAC) is a validated tool for assessing basic mobility.
- Existing measures may not adequately capture the functional status of patients at the lowest levels of mobility.
- Enhancing measurement precision for this population is crucial for effective rehabilitation and care planning.
Purpose of the Study:
- To expand the AM-PAC Inpatient Mobility Short Form (IMSF) to better assess patients with very low mobility.
- To improve the measurement properties of the AM-PAC IMSF at the lower end of the functioning spectrum.
Main Methods:
- Development and testing of new items for the AM-PAC IMSF using item response theory (IRT).
- Item generation, calibration, field testing, and a longitudinal pilot study were conducted.
- The study involved 502 inpatients with low mobility scores (≤15) and a pilot group of 8 patients.
Main Results:
- Fifteen new AM-PAC items were created, with two demonstrating significant utility.
- The addition of these two items reduced the floor effect of the AM-PAC IMSF by 19%.
- Improved statistical power, measurement breadth, and sensitivity were observed with the enhanced measure.
Conclusions:
- Adding two new items to the AM-PAC IMSF effectively addresses limitations in measuring mobility at lower function levels.
- The enhanced AM-PAC IMSF provides a more sensitive and robust assessment for severely mobility-impaired patients.
- This expansion improves the ability to track functional changes and inform care in post-acute settings.
