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JEPonline
Functional Fitness Test for Screening the Risk of Falls in the Elderly: Using Decision Tree Technique
Tachapon Tongterm1, Areerat Suputtitada 2 , Chaipat Lawsirirat1, Prawit Janwantanakul3
1Faculty of Sports Science, Chulalongkorn University, Bangkok, Thailand, 2Department of Rehabilitation Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
3Department of Physical Therapy, Faculty of Allied Health Science, Chulalongkorn University, Bangkok, Thailand
ABSTRACT
Tongterm T, Suputtitada A, Lawsirirat C, Janwantanakul P Functional Fitness Test for Screening the Risk of Falls in the Elderly: Using Decision Tree Technique. JEPonline 2015;18(6):104-111. The aim of this study was to make the Functional Fitness Test for screening the risk of falls in the elderly by using the Decision Tree Technique. Selected by Multistage Random Sampling, we analyzed elderly subjects in 64 districts in 16 provinces in Thailand. The cross-sectional study consisted of 5,632 elderly (of which 1,869 were men and 3,763 were women). The subjects’ physical fitness parameters (muscle strength, aerobic endurance, flexibility, and agility/balance) were studied using six different fitness tests: Chair Stand, Arm Curl, Step in Place, Chair Sit-and-Reach, Back Scratch, and the 8 Foot Up and Go. The fall risk parameter assessed was Berg Balance Scale (BBS). The analysis of Functional Fitness Test for screening the risk of falls in the elderly used the Decision Tree Technique algorithm C4.5 (J48). The 8 Foot Up and Go, Chair Stand, and Step in Place predicted the risk of falls in the elderly with accuracy in prediction (Correctly Classified Instances) equal to 95.76%. When using the Berg Balance Scale test as the dependent variable, the BBS was ≥45 points (meaning, low risk of fall) and when it was <45 points (a high risk of fall) for classifying the risk of falls in the elderly, with Decision Tree Technique model gave information that functional fitness in the 8 Foot Up and Go, Chair Stand, and Step in Place classified the risk of falls in the elderly with level of Correctly Classified Instances equal to 95.76%.
Key Words: Functional fitness, Falls, Elderly, Decision tree
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INTRODUCTION
It is common knowledge that falls are a frequent occurrence in the elderly. Fortunately, many of the risk factors have been identified. For example, there are balance considerations, activity levels, the effects of medication, and the loss of muscle strength. Early detection is important along with exercise program to strengthen the musculoskeletal system. Often, the result is a significant reduction in the risk of falling among elderly persons. Early acknowledgment of impairments and functional limitations associated with reduced mobility, deconditioning, and risk of injury is critical to decreasing falls. Also, physical examination of the neurological system relative to clinical gait analysis and joint motions is necessary to help prevent future falls. Hence, there is clear evidence that screening of diseases and fall risk factors in the elderly in conjunction with properly prescribed exercise programs will help to improve overall quality of life by reducing the frequency and serverity of falls.
Functional fitness consists of muscular strength, aerobic endurance, flexibility, agility, and balance. With the right exercise program to build functional fitness, the risk of falling in the elderly can be decreased (3,9,12). In fact, Toraman and Yildirim (11) reported that the risk of falls is highly correlation with balance and muscular strength of arms and legs. In agreement, Shin and colleagues (10) reported that the elderly who fall less often than the elderly with fall problems have a more efficient muscular system with better balancing skills.
Although Rogers et al. (9) reported that muscle strength test and performance measures that consist of balance test, functional reach test, limits of stability, the 8 Foot Up and Go, and “walking around two cones test” are helpful in assessing the risk of falls in the elderly, there is still inconsistency in the knowledge and application of physical fitness test in determining the risk of falls in the elderly population. Hence, the purpose of this study was to analyze the functional fitness test for screening the risk of falls in the elderly by using the Decision Tree Technique.
METHODS
Subjects
Multistage random sampling was used to identify 5,632 Thai elderly males and females who were between 60 and 99 yrs of age. The subjects consisted of 1,869 males and 3,763 females from 64 districts in 16 provinces throughout Thailand (selected by Multistage Random Sampling). The subjects gave consent to participate in the study and finished the test battery within 1 day. The ethics review committee for research involving human research subjects of Chulalongkorn University approved the study protocol. All subjects signed an informed consent form prior to the study getting underway.
Procedures
Six different fitness tests (Chair Stand, Arm Curl, Step in Place, Chair Sit-and-Reach, Back Scratch, and the 8 Foot Up and Go) were used to determine the subjects’ muscle strength, aerobic endurance, flexibility, and agility/balance. The Berg Balance Scale (BBS) was used to assess the subjects’ fall risk parameters. The analysis of functional fitness test for screening the risk of falls in the elderly was carried out using the Decision Tree Technique algorithm C4.5 (J48).
Functional Fitness Test
Researchers selected lists of six functional fitness test from the Senior Fitness Test (5,7,8) as follows Chair Stand, Arm Curl, Step in Place, Chair Sit-and-Reach, Back Scratch, and the 8 Foot Up and Go.
Assessment of Fall Risk
The Berg Balance Scale (BBS) was used to determine the risk of falls during a series of predetermined tasks. It is a 14 item list with each item consisting of a five-point ordinal scale ranging from 0 to 4, with 0 indicating the lowest level of function and 4 the highest level of function and takes approximately 20 minutes to complete.
1. Sitting to Standing
2. Standing Unsupported
3. Sitting Unsupported
4. Standing to Sitting
5. Transfers
6. Standing with Eyes Closed
7. Standing with Feet Together
8. Reaching Forward with Outstretched Arm
9. Retrieving Object from Floor
10. Turning to Look Behind
11. Turning 360°
12. Placing Alternate Foot on Stool
13. Standing with One Foot in Front
14. Standing on One Foot
A score of 45 has been shown to be an appropriate cut-off for safe independent ambulation and the need for assistive devices or supervision (1,2,4,6). A score of 56 indicates functional balance. A score of <45 indicates individuals may be at greater risk of falling.
Statistical Analysis
The raw data of 5,632 collections were analyzed in Weka 3.6.12 program (open source software for data mining) using the Decision Tree Technique algorithm C4.5 (J48), which is a cross validation technique to verify by random sampling with the data divided into group. In case of k-fold cross validation was halve the data to k part and calculated k time, each time used the data of k as a testing and used the data k-1 for learning data.
RESULTS
The cross-sectional study consisted of 5,632 elderly (of which 1,869 were men and 3,763 were women). The subjects’ age range was 60 to 99 yrs of age. Their mean BMI was 23.70 ± 4.46 kg·m-2 with 458 elderly (8.13%) with a BMI of <18.5 kg·m-2, 1,854 elderly (32.92%) with a BMI of 18.5 to 22.9 kg·m-2, 3,320 elderly (58.95%) with a BMI of ≥23 kg·m-2. The functional fitness tests for the elderly classified by age range are presented in Table 1. The BBS scores for the elderly classified by age range are presented in Table 2. The analysis of functional fitness test for screening risk of falls for the elderly using the Decision Tree Technique algorithm C4.5 (J48) is presented in Figure 1.
Table 1. Functional Fitness Tests for the Elderly Classified by Age Range.
Functional Fitness Test / 60-64 yrs(n = 1,633) / 65-69 yrs
(n = 1,449) / 70-74 yrs
(n = 1,105)
Back Scratch (cm) / Mean ± SD / Mean ± SD / Mean ± SD
- left hand on top / -13.7 ± 12.2 / -14.8 ± 12.7 / -18.0 ± 12.7
- right hand on top / -8.1 ± 11.9 / -9.0 ± 12.3 / -12.2 ± 12.8
Chair Sit-and-Reach (cm)
- stretch the left leg / 11.2 ± 7.4 / 11.5 ± 7.8 / 10.1 ± 8.1
- stretch the right leg / 11.1 ± 7.6 / 11.6 ± 7.7 / 10.2 ± 7.8
8 Foot Up and Go (sec) / 7.5 ± 2.2 / 7.8 ± 2.3 / 8.8 ± 3.4
Arm Curl (number of curls)
- left arm / 19.9 ± 4.7 / 19.9 ± 4.7 / 18.2 ± 3.8
- right arm / 19.5 ± 4.7 / 19.5 ± 4.7 / 17.8 ± 3.7
Chair Stand (number of stands) / 15.4 ± 4.1 / 15.3 ± 4.1 / 13.9 ± 3.6
Step in Place (number of steps) / 90.9 ± 19.6 / 89.3 ± 19.2 / 82.4 ± 19.3
Functional Fitness Test / 75-79 yrs
(n = 848) / 80-84 yrs
(n = 394) / 85 yrs
(n = 203)
Back Scratch (cm) / Mean ± SD / Mean ± SD / Mean ± SD
- left hand on top / -19.4 ± 13.0 / -22.3 ± 12.6 / -25.9 ± 13.7
- right hand on top / -13.2 ± 13.5 / -15.6 ± 14.1 / -19.6 ± 14.5
Chair Sit-and-Reach (cm)
- stretch the left leg / 9.9 ± 8.2 / 8.9 ± 7.1 / 5.5 ± 9.2
- stretch the right leg / 10.0 ± 7.7 / 9.5 ± 6.8 / 6.4 ± 8.4
8 Foot Up and Go (sec) / 9.7 ± 4.2 / 11.9 ± 5.2 / 14.6 ± 7.6
Arm Curl (number of curls)
- left arm / 17.5 ± 4.3 / 15.9 ± 4.1 / 14.5 ± 4.1
- right arm / 17.0 ± 4.3 / 15.6 ± 3.7 / 14.1 ± 3.6
Chair Stand (number of stands) / 13.1 ± 3.9 / 12.1 ± 5.0 / 10.6 ± 3.7
Step in Place (number of steps) / 78.3 ± 21.9 / 71.0 ± 23.5 / 63.9 ± 26.0
Table 2. BBS Score for the Elderly Classified by Age Range.
BBS Score / 60-64 yrs(n = 1,633) / 65-69 yrs
(n = 1,449) / 70-74 yrs
(n = 1,105)
Normal (BBS = 45-56) / 19(1.16) / 18(1.31) / 46(4.16)
High Risk (BBS <45) / 1,614(98.84) / 1,431(98.69) / 1,059(95.84)
BBS Score / 75-79 yrs
(n = 848) / 80-84 yrs
(n = 394) / 85 yrs
(n = 203)
Normal (BBS = 45-56) / 65(7.67) / 71(18.02) / 62(30.54)
High Risk (BBS <45) / 783(92.33) / 323(81.98) / 141(69.46)
*BBS Scores = Berg Balance Scale, number (%)
Figure 1. The Analysis of Functional Fitness Test for Screening Risk of Falls in the Elderly using the Decision Tree Technique Algorithm C4.5 (J48).
The analysis of the Functional Fitness Test for screening the risk of falls in the elderly found that: (a) balance and agility tested by the 8 Foot Up and Go test; (b) strength of lower extremities tested by the Chair Stand; and (c) cardiorespiratory endurance tested by the Step in Place can be used to determine the risk of falls (Figure 1). The Berg Balance Scale produced two important findings.
First, when the 8 Foot Up and Go test was >11 sec and the Chair Stand was 9 times, the elderly subjects were classified as a regular group with a low of risk of falls (with a BBS score 45 points). When the 8 Foot Up and Go was 11 sec and the Chair Stand was 9 times, and the Step in Place was 55 times, the elderly subjects were classified as a regular group with a low of risk of falls (with a BBS score 45 points). When the 8 Foot Up and Go was 11 sec and the Chair Stand was 9 times, and the Step in Place was 55 times, the elderly subjects were classified as a risk group with a high of risk of falls (with a BBS score 45 points).
Second, when the 8 Foot Up and Go was 11 sec, the elderly subjects were classified as a regular group with a low of risk of falls (with a BBS score 45 points).
Table 3. Confusion Matrix of Model for Functional Fitness Criteria in Screening the Risk of Falls for the Elderly.
A / B / <-- Classified as5,205 / 146 / | a = A
102 / 179 / | b = B
Class A referred to Berg Balance Scale (≥45 points). Class B referred to Berg Balance Scale (45 points).
Table 4. Detailed Accuracy by Class of Model for Functional Fitness Criteria in Screening the Risk of Falls for the Elderly.
TP Rate / FP Rate / Precision / Recall / F-Measure / ROC Area / Class0.97 / 0.36 / 0.98 / 0.97 / 0.98 / 0.91 / A
0.64 / 0.03 / 0.55 / 0.64 / 0.59 / 0.91 / B
0.96 / 0.35 / 0.96 / 0.96 / 0.96 / 0.91 / Weighted Avg.
Class A referred to Berg Balance Scale (≥45 points). Class B referred to Berg Balance Scale (45 points).
DISCUSSION
The 8 Foot Up and Go, Chair Stand, and Step in Place predicted the risk of falls for the elderly with the accuracy in prediction (Correctly Classified Instances) equal to 95.76%. The 8 Foot Up and Go was used to assess the subjects’ agility and dynamic balance. Both agility and dynamic are important in tasks that require quick maneuvering, such as getting off a bus in time or getting up to attend to something in the kitchen, to go to the bathroom or to answer the phone (5,7,8). The Chair Stand was used to assess lower body strength, which is important for numerous tasks such as climbing stairs, walking, and getting out of a chair, tub or car (5). The Step in Place is the alternate aerobic endurance test. This is important when space limitations or weather prohibits taking the 6-Minute Walk Test (7,8).
The Arm Curl was used to assess the subjects’ upper body strength, which is needed to perform household and other activities involving the lifting and carrying of groceries, suitcases, and grandchildren (7,8). The Chair Sit-and-Reach was used to assess lower body flexibility that is important for good posture, for normal gait patterns, and for various mobility tasks, such as getting in and out of a bathtub or car (5,7,8). The Back Scratch was used to assess subjects’ upper body (shoulder) flexibility, which is important when combing hair, putting on overhead garments, and reaching for a seat belt (5,7,8).