Validity and Reliability of 2 Minutes Walking Test in Frailty Elderly

Niken Pratiwi

, Rwahita Satyawati

, Damayanti Tinduh

, Soenarnatalina Melaniani

, Mahmuddah

Mahmuddah

Department of Physical Medicine and Rehabilitation, Dr. Soetomo General Hospital, Faculty of Medicine,

University of Airlangga, Surabaya, Indonesia

Department of Biostatistics and Population Study, Faculty of Public Health, University of Airlangga, Surabaya, Indonesia

nlk3np@gmail.com

Keywords: 2MWT, 6MWT, Frailty, Elderly, Validity, Reliability

Abstract: Frailty and age-related conditions are associated with morbidity and mortality. The 6-minute walk test

(6MWT) has been recommended by the American Thoracic Society to measure exercise capacity, but it is

time-consuming for the investigator and exhausting for frailty elderly. This study aims to investigate the

validity and reliability of 2 minutes walking test (2MWT) as measurements of physical performance. A

cross-sectional study was performed. Each subject performed 6MWT as a gold standard and two trials of

2MWT in two consecutive days at approximately the same time. The walking test was performed in the

same corridor with the same starting point. The subject was allowed to used ambulation aid. Frailty was

measured using the Cardiovascular Health Study score. The final subjects included sixty elderly (26 men, 34

women with mean age 73.40 years old). Pearson's r correlation of VO2max between 6MWT and 2MWT

was strong (r= 0.791, p=0.000). The 6MWT and 2MWT showed excellent reliability (ICC=0.926, p=0.000).

The 2MWT was shown to be a reliable and valid test for assessment of exercise capacity following

rehabilitation in frailty elderly. It is practical, simple, and well-tolerated by frailty Elderly.

1 INTRODUCTION

Frailty is a typical health condition associated with

the aging process that is when the body's system

gradually loses its ability to work. About 10% of

people over 65 years experience frailty, increasing to

between a quarter and half of those aged over 85

years (Clegg, 2013). Frailty can be a cause of

disability in some patients (BGS, 2014). Decreased

mobility, functional capacity and/or basic activities

of daily life (ADL) such as bathing, dressing, and

walking occur in 20-30% of the elderly population

over 70 years (Manton, 2000).

Mobilization ability is one of the most important

factors for assessing the level of health and well-

being in the elderly. Functional mobility and

independence are the main objectives of the

rehabilitation program. Functional capacity reflects a

person's cardiorespiratory capacity. Assessment of

cardiorespiratory ability was generally assessed by

measuring maximum oxygen uptake (maximal

oxygen uptake/VO2max) (Sykes, 2004), but the

measurement of VO2max directly requires complex

equipment and laboratories, specific and expensive

equipment, supervision of a professional medical

team, and also consideration of the motivation and

physical effort of the subject to carry out the training

test. Therefore an alternative test is needed to

estimate VO2max with the submaximal training test

(Katch, 2011).

The 6-minute walking test (6MWT) is a test

standard developed by the American Thoracic

Society in 2002 (ATS, 2002). However, this test has

limitations on the elderly, especially the elderly with

frailty. A 6-minute walking test (6MWT) is too

tiring, takes longer and increases the risk of falling

for elderly frailty, 2-minute walking test (2MWT)

can be an alternative. The 2-minute walking test is

considered to have the ability to assess exercise

tolerance (Hiengkaew, 2012).

At present, there are no research data on the

validity and reliability of 2MWT in elderly with

frailty, and 2MWT is an easy, inexpensive and safer

walking test for frailty elderly people. Researchers

242

Pratiwi, N., Satyawati, R., Tinduh, D., Melaniani, S. and Mahmuddah, M.

Validity and Reliability of 2 Minutes Walking Test in Frailty Elderly.

DOI: 10.5220/0009088802420247

In Proceedings of the 11th National Congress and the 18th Annual Scientiﬁc Meeting of Indonesian Physical Medicine and Rehabilitation Association (KONAS XI and PIT XVIII PERDOSRI

2019), pages 242-247

ISBN: 978-989-758-409-1

are interested in researching the validity and

reliability of 2MWT in the elderly with frailty.

2 METHODS

This study was an observational analytic study with

a cross-sectional study to determine the correlation

between the values of anthropometric parameters of

body weight, height, age, and gender from 2MWT

with VO2max from 6MWT. Besides, an assessment

of 2MWT reliability (test-retest) was also carried out

by measuring 2 times (1 consecutive day) by the

same examiner (interrater). We hypothesize that the

2-minute walking training test (2MWT) has validity

and reliability on the assessment of functional

training capacity compared to 6MWT in frailty

elderly.

The research will be conducted at Griya Wreda

Jambangan Surabaya and carried out in November

2018. The target population of this study was Frailty

Elderly with a sample size of 60 subjects taken

based on simple random sampling, which was,

calculated accordingly the following formula:

 





























(1)

Description:

 



Alpha Error Rate (5%)

  

 Beta Error Rate (10%)

 



    

 





  





  

In this study, inclusion and exclusion criteria

were applied. Inclusion Criteria are: 1) Age more

than or equal to 60 years. 2) Frailty criteria based on

the Cardiovascular Health Study. 3) Good hearing

function. Checked with a modified whisper test and

said to be normal if you could hear 80% of all the

items tested according to the procedure. 4) Good

vision function. Judged by a visual inspection using

Snellen u cards at a distance of 6 meters. 5) Can

understand and follow verbal instructions well. 6)

Independent ambulation with or without walking

aids. 7) Willing to participate in this study by

signing an informed consent sheet after obtaining an

explanation.

While the exclusion criteria used in this study

were 1) Being undergoing a routine physical

exercise program that aims to improve walking

speed and lower limb muscle mass in the past month.

2) Severe cognitive impairment was assessed using

the Mini-Mental State Examination questionnaire

(MMSE <23). 3) Having dementia. 4) Suffering

from severe cardiorespiratory disorder 5) Having

acute-severe knee OA according to clinical

appearance, 6) Chronic illness / that causes other

long-term disabilities (eg. ambulation disorders due

to stroke, uncontrolled diabetes, balance disorders

due to intracranial or extracranial processes, visual

disturbances, etc). 7) Falling risk is assessed by the

Timed Up and Go Test, for risk fell in the elderly

population ≥ 13.5 seconds.

Data from the results of the examination of

anthropometric response parameters are displayed

descriptively in table form. For correlation analysis

between the values of weight, height, age and

walking speed when 2MWT with VO 2max when

the 6MWT training test is used the Pearson

correlation test. If a good correlation is obtained,

then it will be followed by linear regression between

each parameter of 2MWT and multiple regression

with VO 2max when the training test runs for 6

minutes to obtain the prediction (formula) of VO

2max prediction. The interclass correlation

coefficient (ICC) test was used for reliability

analysis (test-retest reliability) of VO 2max 2MWT.

Data analysis was performed using SPSS 22 and

Lisrel.

3 RESULTS

This research was conducted by setting a place at the

Jambangan Surabaya nursing home. The number of

elderly who can be ambulated is 102 elderly.

Twenty-two elderly were included in the exclusion

criteria due to 8 dementia disorders, 5 elderly with

visual impairment and 8 elderly with hearing

impairment. Sixty elderly subjects who met the

inclusion and exclusion criteria completed the

2MWT I (first) and II (second) tests, as well as the

6MWT test. The characteristics of the research

subjects are shown in Table 1.

Validity and Reliability of 2 Minutes Walking Test in Frailty Elderly

243

Table 1: Characteristics of Research Subjects.

Variable

Min

Maks

Mean ± SD

Age (years)

73.40 ± 8.928

Weight (Kg)

51.70 ± 10.617

Height (cm)

130

175

153 ± 0.103

BMI

(Kg/m2)

14.84

33.32

21.93 ± 3.918

Nb: SD = Standard Deviation, Min = Minimum Value, Max = Maximum Value.

Table 2: Percentage of Frailty.

Sex

Frailty

Pre frailty

Total

7 (26.9 %)

19 (73.1 %)

26 (100 %)

16 (47.1%)

18 (52.9 %)

34 (100 %)

Total

23 (38.3 %)

37 (61.7 %)

60 (100 %)

Nb: Sex = Gender, L = Male, P = Female.

Table 3: Correlation of VO

2max

2MWT and 6MWT

Parameter

2max

6MWT

2max

2MWT

2max

6MWT

0.791**

0.000

2max

2MWT

0.791**

0.000

Description: r = Pearson correlation coefficient, p = p value, N = number of subjects. Significant correlation at p <0.01 (2-

tailed)

Table 4: Test-retest reliability of Vo2Max 2MWT.

Parameter

ICC

CI 95%

2max

0.925

0.874 –

0.955

Description: ICC = Interclass Correlation Coefficient, CI Confidence Interval, TDS = Systolic Blood Pressure, TDD =

Diastolic Blood Pressure

KONAS XI and PIT XVIII PERDOSRI 2019 - The 11th National Congress and The 18th Annual Scientiﬁc Meeting of Indonesian Physical

Medicine and Rehabilitation Association

244

Based on the Frailty score Cardiovascular Health

Study (CHS) Table 3.2 found 26 research subjects

male 7 (26.9%) including frailty and 19 (73.1%) pre-

frailty people. For female subjects, 16 (47.1%) were

frailty and 18 (52.9%) were pre-selected frailty.

To calculate the VO2max correlation from

2MWT and 6MWT, then carried out the 2MWT

validity assessment. The vo2max value obtained

from the equation calculated using Confirmatory

Factor Analysis. Table 3.3 illustrates the relationship

between the VO 2max value of the 2MWT and

6MWT submaximal load training tests. From the

calculation of the Pearson correlation coefficient the

strong correlation was found (r = 0.791; p = 0.000)

between the VO value of 2max. The training test

was two minutes and six minutes.

2MWT reliability (test-retest) assessment was

carried out by comparing VO2max values on two

measurements (between 2MWT I and 2MWT II)

within a span of 1 day carried out by the same

examiner (interrater), at the same hour and place.

4 DISCUSSION

In this study, 60 elderly subjects met the inclusion

criteria and were not included in the exclusion

criteria and were willing to take part in the study

after signing informed consent. The age of the

subjects in this study was 60-96 years (mean 73.40

years). The body mass index of the subjects in this

study ranged from underweight to obese, namely

14.84 - 33.32 Kg/m

. The normal value of the

Indonesian body mass index is 18.5 - 25 Kg/m

(Harahap, 2005). All research subjects completed

the 2MWT I (first) training test and 6MWT training

test at the first meeting, as well as the 2MWT II

(second) training test 1 day after the first. Before

carrying out the training test the subject's

cardiorespiratory parameters were measured. The

mean resting heart rate at the first meeting (before

2MWT I) was 77.20 beats/minute. The average

resting heart rate is not much different when

compared to the average resting heart rate during the

second meeting (before 2MWT II), with an average

of 77.30 beats/minute. From the paired t-test there

was no significant difference between

cardiorespiratory parameters (heart rate, systolic

blood pressure, diastolic blood pressure, and pulse

blood pressure) pre-2MWT I and pre-2MWT II with

p values for all parameters >0.05. With this, it can be

said that the conditions or cardiorespiratory

parameters break the subjects between the first and

second meetings in this study are the same. In this

study, the VO2max equation is calculated using

Confirmatory Factor Analysis.

Prediction of VO2max values can be done using

anthropometric parameters. This, of course, can be

done if the anthropometric parameters have a good

correlation with the VO2max value when the

submaximal stress test measured using 6MWT. The

statistical analysis used for this purpose is linear

regression. From the linear regression analysis, a

regression equation will be obtained which states the

relationship of the variable you want to predict with

the measured variable (Tumbelaka, 2014). In this

study, the predicted variable is the value of VO2max

and the measured variable is the anthropometric

parameter namely age, weight, height, and walking

speed (m / min). The regression equation for

VO2max prediction is shown in Table 4.

Table 4: Regression equation for prediction of VO

2max.

Equation

2max

= 71.4 %)

- 116.244 + (1.17 x umur)

= 66.6%)

18.164 – ( 0.918 x BB)

III (R

= 62.4%)

105.432 – ( 0.878 x TB)

IV (R

= 93.6%)

- 0.854 x

Running speed

Description: BB = Body Weight, TB = Height, R =

Coefficient of determination

From the regression equation above we can see

that the highest r-value (r = 1.00) is obtained if all

four parameters (weight, height, age, sex, and

walking speed) during the 2MWT training test are

included in the calculation. The higher the R-value

of a regression equation, the higher the accuracy of

the equation (the prediction results are getting closer

to the actual value with a smaller error rate). Thus,

the best equation from the 2MWT training test for

the prediction of VO2max:

The submaximal training test developed in this

study is a 2-minute walking training test (2MWT).

2Max

(mL/KgBB/minute) =

2.809 + (0.868xU) – (0.0412 x BB) –

(0.382 x TB) – (0.474 x Walking speed) (2)

Nb:

- U = Age (Years)

- BB = Weight (Kg)

- TB = Height (Cm)

- Running Speed (m/minutes)

- Estimation of Error Standart = 0.119

Validity and Reliability of 2 Minutes Walking Test in Frailty Elderly

245

These submaximal training test subjects were asked

to walk for 2 minutes in a 30m corridor. Unlike the

6MWT submaximal test as the gold standard, 2

minutes test in this study was chosen to minimize

muscle fatigue, especially in untrained subjects.

Besides, the cardiorespiratory physiological

condition remained (steady-state) when the exercise

test was reached after 2-3 minutes (Prentice, 2011).

So that 2 minutes was sufficient to obtain the

cardiorespiratory parameters of the condition during

the training test. Maximum oxygen consumption

(VO2max) is the largest amount of oxygen that can

be inhaled during a training test, which involves a

large part of the total muscle mass. This is

considered the best measure of cardiovascular

fitness and aerobic capacity.

This study found that there was a significant

increase in walking distance in the 2MWT repeat

trial in frailty elderly. According to a study

conducted by Brooks in 2007 found an increase in

walking distance in amputee patients and heart

surgery patients who did not experience

improvement after three trials. Repeated trials in

pediatric patients with cystic fibrosis revealed no

significant difference in walking distance. In

contrast, repeated trials in pediatric patients with

cystic fibrosis revealed no significant difference in

walking distance (Upton, 2015). Guyatt et al.

Showed that, in repeated trials of patients with

limited chronic airflow and/or chronic heart failure,

there was a stable training effect after two trials. An

interesting finding from this study is that walking

distance in 2 minutes increased during the two trials.

VO2max value generally decreased according to

age. Decreasing VO2max 8-10% per decade in both

mobile and inactive populations (Pin, 2012). In VO

2max women are lower because muscle mass is

smaller than men. Because both of these affect VO

2max (Tumbelaka, 2014), anthropometric

parameters are used to find out VO2max. In this

study, 2MWT validity was assessed by analyzing

anthropometric parameter correlations (age, weight,

height, sex, and walking speed) at 2MWT against

VO2max values measured using equations

calculated using Confirmatory Factor Analysis.

From the calculation of the Pearson correlation

coefficient, we found a significant correlation (r =

0.791) between the VO2max value at 2MWT and

6MWT.

Based on the interpretation of the Pearson (r)

correlation coefficient by Tumbelaka et al, the

correlation is stated to be good if the value of r =

>0.8; medium if the value of r = 0.6 - 0.79; weak if

the value of r = 0.4 - 0.59; and very weak if the

value of r = <0.4. Correlation values obtained in this

study indicate that the 2MWT submaximal training

test has quite good validity in the assessment of

cardiorespiratory capacity in frailty elderly.

The VO2max correlation value in this study is

not much different when compared with the VO

2max correlation value in a study conducted by

Bohannon et a1 and Bernstein et a1 both evaluated

concurrent validity in individuals with respiratory

disease and reported that the running distance at

2MWT was highly correlated with walking distance

in 6 and 12 minutes running test (r = 0.892–0.995).

Bernstein examined the validity of individuals with

COPD and reported that walking distance in 2

minutes was moderate to maximal correlated and

strongly correlated with submaximal oxygen

consumption (r = 0.45; r = 0.55; respectively).

Furthermore, Upton et al. Concluded that, in

children with cystic fibrosis who have a near-normal

respiratory function, 2MWT is a measure that is

more discriminatory than the peak expiratory flow

rate. In individuals with lower limb amputations, a

distance of 2MWT correlates with measures of

physical function and prosthetic use.

Reliability Test is a fundamental measurement

property that is relatively easy to determine and

quantified in terms of the level of consistency and

repetition when managed properly in similar

circumstances for certain populations. Assessment

of reliability (test-retest reliability) of 2MWT in this

study was conducted by comparing the parameter

values of age, weight, height, gender and walking

speed with VO 2max using the prediction formula

on two measurements (between 2MWT-I and

2MWT-II) in the 1 consecutive day by the same

examiner (interrater).

The 2MWT reliability for age parameters is quite

good with a value of R 2 = 71.4% (SE = 0.151).

2MWT reliability for weight parameters is quite

good with a value of R 2 = 66.6% (SE = 0.135).

Reliability for the Height parameters is quite good

with an ICC value of 62.4% (SE = 0.145).

Reliability for the sex parameter is quite good with

an ICC value of 58.1% (SE = 3.132). If the four

parameters (weight, height, age, gender, and walking

speed) during the 2MWT training test are included

in the calculation, the ICC score is very good at

92.5%. The higher the ICC value of an equation, the

higher the reliability. This shows that the 2MWT

submaximal training test has good reliability in the

assessment of cardiorespiratory capacity.

KONAS XI and PIT XVIII PERDOSRI 2019 - The 11th National Congress and The 18th Annual Scientiﬁc Meeting of Indonesian Physical

Medicine and Rehabilitation Association

246

5 CONCLUSIONS

The 2-minute walking exercise test (2MWT) has

good validity where anthropometric parameters of

weight, height, age, sex and walking speed when

2MWT have a significant correlation with VO 2max

values during the 6MWT submaximal training test.

The 2-minute walking test (2MWT) has very good

reliability (test-retest reliability).

REFERENCES

American Thoracic Society (ATS)., 2002. ATS Statement:

Guidelines for the Six-Minute Walk Test. American

Journal of Respiratory Critical Care

Medicine,166(111117).DOI:10.1164/rccm.166/1/111

Bernstein, ML., Despars, JA., Singh, NP., Avalos, K.,

Stansbury, DW., Light RW., 1994, Reanalysis of the

12 minute walk-in patients with chronic obstructive

pulmonary disease, Chest, 105:163–7.

Bohannon, RW., Bubela, D., Magasi, S., McCreath, H.,

Wang, YC., Reuben, D., Gershon, R., 2014,

Comparison of walking performance over the first 2

minutes and the full 6 minutes of the Six-Minute Walk

Test. BMC Research Notes, 7, 269.

http://doi.org/10.1186/1756-0500-7-269

British Geriatric Society (BGS)., 2014. Fit For Frailty,

Consensus Best Practice Guidance for the Care of

Older People Living with Frailty in Community and

Outpatient Setting, Majory Warren House, London.

Brooks, Dina., 2002, Reliability of the two-minute walk

test in individuals with transtibial amputation,

Archives of Physical Medicine and Rehabilitation,

83(11), 1562–1565.

Brooks, D., Parsons, J., Hunter, JP., Devlin, M., Walker, J.,

2001, The 2-minute walk test as a measure of

functional improvement in persons with lower limb

amputation, Arch Phys Med Rehabil, 82:1478–83.

Clegg, A., Young, J., Iliffe, S., Rikkert, MO., Rockwood,

K., 2013, Frailty in elderly people, Lancet,

381(868):752-762.

Guyatt, GH., Sullivan, MJ., Thompson, PJ., Fallen, EL.,

Pugsley, SO., Taylor, DW., 1985, The 6-minute walk:

a new measure of exercise capacity in patients with

chronic heart failure. Can Med Assoc J, 132(8):919-23.

Harahap, H., Widodo, Y., Mulyati Sri., 2005, Penggunaan

berbagai cut-off indeks massa tubuh sebagai indikator

obesitas terkait penyakit degeneratif di Indonesia. Gizi

Indon, 31, pp. 1-12.

Hiengkaew, V., Jitaree, K., Chaiyawat, P., 2012, Minimal

detectable changes of the Berg balance scale, Fugl–

Meyer Assessment Scale, Timed "Up & Go" Test, gait

speeds, and 2-minute walk test in individuals with

chronic stroke with different degrees of ankle plantar

flexor tone, Archive of Physical Medicine

Rehabilitation, 93:1201–1208.

Katch, VL., McArdle, WD., Katch, F. I., 2011, Measuring

and Evaluating Human Energy-Expenditure Capacities

During Exercise, In: Essential of Exercise Physiology,

5th edition, Philadelphia: Lippincott William &

Wilkins, pp. 203-233.

Manton, KG., Land, KC., 2000, Multidimensional

Disability/Mortality Trajectories at Ages 65 and Over:

The Impact of State Dependence, Social Indicators

Research, 51: 193.

Pin, TW., Lewis, J., 2012, Pilot normative study on 2- and

6-minute walk tests on typically developing children

in Australia, Australasian Academy of Cerebral Palsy

and Developmental Medicine Conference.

Developmental Medicine Children Neurology, 54:85.

Prentice, W., 2011, Maintaining Aerobic Capacity and

Endurance during Rehabilitation. In W. Prentice,

Rehabilitation Techniques for Sports Medicine and

Athletic Training, New York: McGraw-Hill, pp. 214-

25.

Sykes, K., Roberts, A., 2004, The Chester Step Test - a

Simple yet Effective Tool for The Prediction of

Aerobic Capacity, Physiotherapy, 90, pp. 183- 188.

Tumbelaka, A. R., Riono, P., Sastroasmoro, S.,

Wirjodiarjo, M., Pudjiastuti, P., Firman, K., 2014,

Pemilihan Uji Hipotesis. In: S. Sastroasmoro & S.

Ismael, eds. Dasar-dasar Metodologi Penelitian Klinis.

Jakarta : CV. Sagung Seto, pp. 328-350.

Upton CJ, Tyrrell JC, Hiller EJ., 2015. Two-minute

walking distance 󳋡 in cystic fibrosis. Arch Dis Child;

63:1444–1448

Validity and Reliability of 2 Minutes Walking Test in Frailty Elderly

247