Mobility Assessment Using Surrogates in Elderly Participants

According to the U.S. Census Bureau projections, the number of persons 65 years of age or older will increase from roughly 40 million in the year 2010, to 88.5 million in 2050, a net increase of 121%. During this same time period, the number of persons 85 years of age or older will increase by 227%; accounting for nearly 5% of the U.S. population. Mobility and functional status are important predictors of outcomes in this rapidly growing elderly population. It has shown that walking speed and physical function, measured by Short Physical Performance Battery (SPPB) are predictors of mortality in community-dwelling older men and women. It was also reported that gait speed predicts incident disability in community dwelling elderly subjects. In our prior study, we have demonstrated that, mobility, assessed using an animated video clip based assessment tool, Mobility Assessment Tool-short form (MAT-sf) predicts postoperative complications, length of stay and nursing home placement in elderly patients (>69) who were undergoing elective surgery that requires overnight hospitalization and more clinical practices use physical function and mobility as a tool to predict outcomes.

However, these assessments are not always readily available, especially in clinical situations when acute illnesses or injuries occurred without any chance to assess the baseline status, such as acute myocardial infract, rapidly progressing sepsis or catastrophic trauma. In these cases, patients are often sedated, intubated, have altered mental status, or too unstable to perform even non-invasive testing. Although some clinicians or researchers feel that surrogate can accurately assess the patients' baseline physical function and mobility status, it was never been tested.

The investigators hypothesize that mobility assessment done on surrogates, using MAT-sf will have high compatibility with the assessment done on elderly patients. Surrogates are defined as a person who spends >2 hours a day or 8 hours a week with the patient and accompany the patient to most of their medical appointments. The investigators will test the hypothesis at the Preoperative Assessment Clinic since this clinic sees high volume of elderly patients and patients at this clinic tend to have their caregiver with them during the appointments.

Investigators will enroll 20 patients in poor mobility group (MAT-sf < 51.38 in men and <45.61 in women), 20 patients into the mid-mobility group (51.38< MAT-sf≤65.5 in men and 45.61≤MAT-sf<54.02) and 20 patients into the high mobility group (MAT-sf>65.5 in men and MAT-sf>54.02 in women) for a total of 60 patients and one surrogate per patient for a total of 120 unique participants.

To assess mobility, participants will be instructed on the use of the Mobility Assessment Tool-short form (MAT-sf). The MAT-sf is a 10-item computer based assessment of mobility using animated video clips. The 10 items in the MAT-sf cover a broad range of functioning. The items include walking on level ground, a slow jog, walking outdoors on uneven terrain, walking up a ramp with and without using a handrail, stepping over hurdles, ascending and descending stairs with and without the use of a handrail, and climbing stairs while carrying bags. The items were previously selected based on individual response and information curves derived from Item Response Theory. Each item is accompanied by an animated video clip together with the responses for that question (number of minutes, number of times, yes/no). The test will be performed on an I-PAD and scores will be saved to an exportable file. The time required to do the test with instructions from the examiner is expected to be no longer than 5 minutes. While the patient is completing the MAT-sf assessment, the surrogate will be directed to a separate room to complete MAT-sf for the patient ("Do you think Mr ** can climb up this hill?) , so there is no interaction between the patient and the surrogate during the assessment. Investigators will measure the compatibility between patients-surrogates mobility using MAT-sf and will also assess the stability of surrogate MAT-sf.