Intra-rater and test-retest reliability of videography observation method to check diversion time in Fukuda step test among college going students
Article information
Abstract
[Purpose]
The Fukuda step test is a valuable tool for identifying vestibular dysfunction in humans. This study evaluated the intra-rater and test-retest reliabilities of videograph observations to determine the diversion time while performing the Fukuda test. This study aimed to determine the use of videographic observation as a beneficial tool for recording real-time assessment procedures in clinical settings.
[Methods]
Fifty college students who were selected based on the inclusion criteria performed three consecutive sessions of the Fukuda step test. Intra-rater and test-retest reliabilities of the videograph observations were identified using the intraclass correlation coefficient (ICC).
[Results]
We noted both, good intra-rater (ICC= 0.78) and moderate-to-good test-retest reliabilities (ICC= 0.69) of the videograph observations.
[Conclusion]
Videographic observation can be used in clinical settings to identify diversion times while performing the Fukuda step test.
INTRODUCTION
The vestibular organs, which are tiny, exquisitely shaped, and confined inside the skull, constantly barrage the brain with signals. These messages are distinct. They describe acceleration, head rotation, translation, and spatial orientation. Accurate and precise detection of head and body displacement in space is essential for crucial functions such as balance, posture control, gait, spatial orientation, and self-motion perception. The vestibular pathway, which begins with two simple but elegant organs embedded in the inner ear, the semicircular canals and the otolith, facilitates this process. These two organs help detect linear and angular acceleration of the head, respectively. The encoded inertial motion signals from the peripheral system are then sent to the central nervous system for processing. Although it is well known that neural circuits mediate automatic processes such as the vestibulo-ocular reflex (VOR) to maintain visual stability and body balance, little is known about how the brain codes vestibular signals for self-motion perception and spatial orientation, particularly in darkness. In particular, a growing number of cortical regions, many of which are also sensitive to visual motion stimuli, show vestibular activity in response to translation or rotation of the head or body in darkness [1]. In order to diagnose unilateral vestibular dysfunction, Unterberger proposed a stepping test with the eyes closed in 1938. Fukuda improved the test and made it popular, naming it the Fukuda Step Test (FST) in 1959. During the FST, patients are asked to stand up, extend both arms, and walk in place with their eyes closed for 50–100 steps. Asymptomatic persons will typically walk straight ahead without turning on either side. Patients with vestibular dysfunction typically deviate > 45° from normative values [2].
Numerous studies have demonstrated the use of the FST to diagnose vestibular dysfunction. For instance, a study conducted to identify the functionality of FST in diagnosing recurrent benign paroxysmal postural vertigo (BPPV) concluded FST to be invaluable in the diagnosis of BPPV since the ratio of FST positivity and negativity was similar in patients with BPPV [2]. To identify the factors affecting spatial parameters in the population, a study was conducted to identify the impact of step height and concurrent cognitive task. The study subsequently revealed influence of these two factors [3]. Significant test-retest reliability of FST was found in study conducted to assess the vestibular system integrations [4]. To our knowledge, there is a scarcity of research providing positive evidence for video-based observation methods in determining the time of diversion during performance of the FST. Hence, we aimed to estimate the intra-rater and test-retest reliability of video-based observations in assessing FST values among collegiate students. We hypothesized that videographic observation is a reliable method for assessing vestibular function.
METHODS
Study settings
A methodological study: An Intra-rater and test-retest reliability study was performed on collegiate students [5]. The recruited study population were collegiate students aged between 18 and 30 years in the Punjab region. A simple random sampling method was used for data collection. Written informed consent was obtained from all participants before the study. Before proceeding, permission to conduct the research was obtained from the college authorities. This study was conducted in accordance with the National Ethical Guidelines for Biomedical and Health Research Involving Human Participants (Indian Council of Medical Research, 2017) and the Declaration of Helsinki (Revised, 2013).
Participants
Inclusion criteria were collegiate adults, both males and females, aged between 18 and 30 years, with no symptoms of dizziness, nausea, or vomiting prior to the study. Students were excluded if they presented with any symptomatic condition related to cardiorespiratory, musculoskeletal, neurological conditions or a positive history of lower-limb surgery in the past year.
Sample size estimation
To determine the sample size for the current study, an unpublished pilot study was conducted with 12 samples. On the basis of pilot study results analyzed in SPSS, Estimating Mean Formula {(1.96)2 (α)2÷ (E)2} was used to calculate the actual sample size for the current study [6]. Minimum required sample for the study was calculated using estimating mean formulae (Z α σ/d)2. By substituting, Z α =1.96; σ (SD) = 12.1 and d (Standard Error of mean) = 3.5, the minimal required sample size was found to be, n = 47. After rounding off, n = 50 was used in this study.
PROCEDURES
All measurements were collected in three sessions conducted at the physiotherapy laboratory by the two raters. Both raters were physical therapists with 3 years of experience and a master’s degree in cardiorespiratory and pediatric neurology. Before proceeding with data collection, the examiner made a 2 × 2 box block inside the examination area using a microporous paper tape. The room selected for data collection was calm and quiet, and had white tiles. The reason for choosing a room with white tiles was to ensure the proper identification of linear and angular accelerations with the participants’ colored footprints. Participants were selected based on simple random sampling. The examiner explained the procedure thoroughly to each participant. After explanation, one examiner obtained all anthropometric measurements (height, weight, and BMI) and demographic details (name, age, and sex). Before proceeding with the main procedure of the FST, the pulse rate was measured using radial artery pulsation. One examiner was already in the examination area with a mobile phone used for videograph observation. A mobile Phone [Apple iOS iPhone 12th Generation Rear camera 16-megapixel (f/1.8)] was used to capture the videos. The examiner stood in front of the participant’s initial position and in the middle of the examination area to determine the time required for diversion. A microporous tape marker was used to identify the starting point and linear or angular acceleration. Subsequently, participants were asked to stand at the starting point after dipping their feet in water. Different water colors were used to identify each participant accurately. After all these arrangements, the FST was performed. Before the FST was administered, the below instructions given to the participant and examiner [5].
Instructions to the participant
● To close their eyes before the start of the test.
● Their shoulder should be flexed in a vertical direction at 90 degrees.
● To start marching as soon as the timer was started.
Instructions followed by examiner
● Stand by the participants to prevent any sort of falls.
● Instruct the patient in layman language in order to avoid any miscommunications.
● Next, start the timer and ask the subject to march in the same place.
● Mark and note when there are any deviations till the end of the test.
● After 1 min, the patient was asked to stop, mark, and measure the area using a measuring tape.
● The linear and angular distances are to be measured with a measuring tape, and the angular deviation is to be measured using a protractor.
Intra-rater reliability
The consistency of the data collected by one examiner over two trials was referred to as intra-rater reliability. The pre- and post-FST, pulse rate (PR) was measured to standardize the rest period. The examiner was required to wait until the post FST pulse rate drops to the pre FST pulse rate (±3 pulse beats). After assessing the participants’ PR, the procedure for determining intra-rater reliability was restarted. Two FST trials were used to determine the intra-rater reliability.
Test-retest reliability
The FST procedure was repeated after 24 h to check test-retest reliability because a minimum 24 hours’ period is required to obtain FST values. A consecutive FST reading was performed on the day after the first reading [7].
Statistical analysis
All statistical analyses were performed using the SPSS software (IBM SPSS V-20 for Windows 10; Armonk, NY, (IBM Group). The Kolmogorov-Smirnov test was used to verify normality, owing to the estimated 50 participants in this study. As the information did not follow typical dissemination patterns, clear measurements were expressed as medians with IQR. The Mann-Whitney U test was used to consider the segment aspects among males and females selected for the study. The intraclass correlation coefficient (ICC) was used to determine the test-retest and intra-rater reliabilities. Shrout and Fleiss utilized an ICC (3, 1-two-way mixed-effect model) for intra-rater and test-retest reliability. If ICC values are <0.25; low, if low to fair (0.25 ≤ rs ≤ 0.5), moderate to good (rs = 0.50–0.75), or strong (rs >0.75) [8].
RESULTS
Demographic details and FST components of males (n=24) and females (n=26) recruited for the study are shown in Tables 1 and 2, respectively. There was no significant difference found between the male and female demographic details and FST components (P > 0.05). A single group was considered for further ICC analyses. The ICC values (Intra-rater and Test-retest) for the diversion time are shown in Table 3.
Baseline demographic dimensions of the participants recruited for the study (n=50)
Components of FST and comparison between males and females recruited for the study
Intraclass correlation coefficient analysis of videograph observation to check diversion time in FST
DISCUSSION
The primary purpose of this study was to determine the intra-rater and test-retest reliability of the videograph method while performing the FST on collegiate students. Fifty college students ranging from ages 18 to 30 participated in this study. It is clear from the analysis that the videograph method has moderate-to-good intra-rater and test-retest reliabilities (ICC between 0.5 and 0.75). As both intra-rater and test-retest reliability were acceptable, videography can be used to check diversion time while performing the FST.
Previous studies have shown good to moderate test-retest reliability of the 50-step FST, but no discussion of the time taken for the diversion has ever been mentioned [9]. In our study, we found that the time taken for diversion during angular displacement ranged from 18 to 30 seconds. We determined the intra-rater and test-retest reliabilities of the videography method while recording the FST in three successive sessions. Intra-rater and test-retest reliabilities were in the moderate-to-good range.
The participants were selected based on predefined in-clusion criteria and volunteered to participate in the study. To make the procedure interesting and motivating, standard instructions were provided to the participants regarding cerebellar function and the importance of the FST. The time chosen for the study is between 9 am and 12 noon to minimize diurnal variation. Blood pressure varies during the day and night, and can be affected by the body circadian effect. A normal circadian effect was observed in the morning, which decreased the chances of fatigue. This helped minimize fluctuating results because of proper concentration in the morning [10].
This study had some limitations. These included unavoidable human errors when measuring linear and angular displacement using a measuring tape, unequal sex distribution, and small sample size. The strengths of this study include its minimal time and space requirements, cost-effectiveness, and ease of understanding and implementation. In the future, this study should be conducted in pediatric and geriatric populations to further explore the screening of vestibular dysfunction in any age group. Correlation studies can be conducted between demographic details and FST components. Regardless of these limitations, the conclusion of our study highlights the identification of FST components, specifically diversion time, using videograph observation.