A Study of Dual-task Exercise Training to Prevent Falls Among Older Adults With Mild Cognitive Impairment

Self-reported number of falls

This measure will reflect change in the incidence of falls as a result of intervention. Study participants will be given a falls calendar to record number of falls at home. Falls are defined as "when you land on the floor or the ground, or fall and hit objects like stairs or pieces of furniture, by accident." This information will be ascertained monthly via a phone call by study assessors

Short Physical Performance Battery

Reflects change in lower extremity function with intervention. This is measured by Short Physical Performance Battery which involves three functional tasks: static balance, gait speed, and getting in and out of a chair, with scores ranging from 0 (worst performance) to 12 (best performance).

Timed Up and Go (TUG)

Reflects change in lower extremity physical function with intervention. This is measured by the Timed Up and Go test (TUG; in seconds) which assesses mobility and fall risk. The test measures the time taken by an individual to stand up from a standard chair, walk a distance of 3 meters, turn, walk back to the chair, and sit down. Lower scores represent better lower extremity physical function.

Dual-task walking

Reflects change in dual-task costs in gait speed with intervention. The TUG test protocol will be repeated under a dual-task condition where the participant is asked to walk while performing an arithmetic task (i.e., starting at the number 81 and sequentially subtracting 5 from the resulting number). Lower scores on this walk indicate better performance. Dual-task walking cost is defined as the difference between single- and dual-task walking speed, expressed in percentage, with less negative values representing improvement in dual-task walking speed relative to single-task walking.

30-second chair stand

Reflects change in lower extremity strength and endurance with intervention. This is measured by the 30-second chair stand test. The test is conducted by asking the participant to stand up from a chair and sit down fully and to perform as many cycles of sit-to-stand-to-sit as possible in 30 seconds. Higher scores (number of stands) represent higher levels of strength and endurance.

Activity-specific Balance Confidence

Reflects change in the perceptions of balance with intervention. This is measured by the Activity-specific Balance Confidence Scale which assesses one's confidence in performing various activities of daily living without compromising one's balance. It includes such items as picking up an object from the floor, standing on a chair to reach, and walking on icy sidewalks. The scale contains 16 items scored on a range from 0% to 100% (0 indicating no confidence and 100 indicating full confidence).

Pittsburgh Sleep Quality Index

Reflects change in quality of sleep with intervention. This is measured by the Pittsburgh Sleep Quality Index which includes seven indices: subjective quality, latency (i.e., time needed to fall asleep), duration (i.e., number of hours of actual sleep per night), efficiency (i.e., total sleep time divided by time in bed, converted to a score of 0-3), sleep disturbances (e.g., waking up in the middle of the night and the like), use of sleep medication, and daytime dysfunction (e.g., having difficulty staying awake during the day). Each of the component scores ranges from 0 to 3, with the PSQI global score ranging from 0 to 21 points, with higher scores indicating poorer sleep quality.

Geriatric Depression Scale

Reflects change in the level of depression with intervention. This is measured by the Geriatric Depression Scale (GDS). The 15-item version of the GDS will be used with the scores ranging from 0 to 15. A score of 0 to 4 is considered to be within the normal range, 5 to 9 indicates mild depression, and a score of 10 or more indicates moderate to severe depression.

EuroQol EQ-5D

Reflects change in quality of life with intervention. This is measured by EuroQol EQ-5D which assesses health status in five domains: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each domain is measured at three levels: no problems (coded as 1), some problems (2), and extreme problems (3). An EQ-5D utility score will be calculated for each participant based on the U.S. population-based (preference-weighted) health index scores on a scale ranging from less than 0 (worst health state) to 1.0 (best or perfect health state).