Inter-device Reliability Research Articles

Validity and Reliability of Omron Pedometers for Prescribed and Self-Paced Walking

The purpose of this study was to examine the validity and reliability evidence for the Omron Healthcare HJ-151 and HJ-720ITC pedometers for prescribed and self-paced walking. A total of 47 adults (24 males, 23 females; age = 24 +/- 4.4 yr.; body mass index = 25.7 +/- 4.2 kg x m(-2)) participated in this study. Under prescribed walking conditions, 34 participants completed three randomized 100-m walking trials through a range of scripted walking speeds (slow, moderate, and very brisk) for each pedometer model. Under self-paced walking conditions, 31 participants completed one 1-mile walk on a standardized course for each model. HJ-151 pedometers were chosen at random from a pool of 54 devices and were worn along the waistband at the right hip, the left hip, and the midback, whereas HJ-720ITC pedometers were chosen from a pool of 24 devices and incorporated right pocket, left pocket, and backpack positions in addition to the three waist-mounted sites. Absolute percent error (APE) scores were calculated to examine pedometer accuracy between actual steps (a criterion measure) and pedometer-determined steps. Coefficient of variation (CoV) was computed to describe interdevice reliability. With the exception of the HJ-720ITC at the backpack position in the prescribed walking setting (mean APE = 3.4%), the HJ-151 and the HJ-720ITC accurately reported step counts under prescribed and self-paced conditions (all APE values <3.0%). Moreover, interdevice reliability evidence was established for the HJ-151 and the HJ-720ITC under prescribed and self-paced conditions (all CoV values <2.1%). The Omron HJ-151 and HJ-720ITC pedometers demonstrated validity and reliability at various mounting positions under prescribed and self-paced walking conditions with both healthy and overweight adults.

Repeatability and interdevice reliability of two portable color selection devices in matching and measuring tooth color

There is a need to know how shade selection devices perform in matching and measuring tooth color, since these functions are usually evaluated independently and may present significant discrepancies. The purpose of this study was to evaluate 2 devices which offer both functions to test the null hypothesis that they present no differences in their repeatability and interdevice reliability relating to the 2 functions. Thirty-one extracted anterior human teeth were measured twice, with each of the devices (ShadeEye NCC and VITA EasyShade), by one investigator experienced and calibrated with both devices. L*a*b* values and shade matches to VITA Classical and Vitapan 3D-Master shade guide systems were determined for all teeth. Paired t tests and intraclass correlation coefficients (ICCs) were used to statistically analyze the data (alpha=.05). The results showed that L*a*b* values with VITA EasyShade were significantly higher than those with ShadeEye NCC (P<.01), with a mean difference of 10.01 Delta E units. Device repeatability ICCs for measuring tooth color ranged from 0.693 to 0.929, with significant differences between devices only with respect to parameter L* (P=.042). Intradevice ICCs for matching tooth color ranged from 0.714 to 0.894, with significant differences between devices only with respect to the VITA Classical shade system (P=.042). Interdevice ICCs for measuring tooth color ranged from 0.402 to 0.486, with no significant differences between L*a*b* parameters, while interdevice matching reliability ranged from 0.189 to 0.430, with no significant differences between shade systems (P>.05). All tooth color parameters were higher with the VITA EasyShade device. Measuring repeatability of the VITA EasyShade was higher than the ShadeEye NCC only for the L* parameter. Matching repeatability of the ShadeEye NCC was higher than the VITA EasyShade for the VITA Classical system. Interdevice measuring reliabilities were not different for the color parameters, but matching reliability of the VITA Classical system was higher than that of the Vitapan 3D-Master.

The validation of a novel activity monitor in the measurement of posture and motion during everyday activities

Background: Accurate measurement of physical activity patterns can be used to identify sedentary behaviour and may facilitate interventions aimed at reducing inactivity. Objective: To evaluate the activPAL physical activity monitor...

Interdevice variability in percent fat estimates using the BOD POD

To evaluate interdevice reliability in body density (Db) and percent body fat (%BF) using air-displacement plethysmography, the BOD POD (BP) body composition system. Duplicate body composition tests were performed in immediate succession on 50 adults (26 M, 24 F; 21-53 y) using two BP units located in the same body composition laboratory. Mean Db and %BF between BP1 and BP2 did not differ significantly for men (DeltaDb = 0.0003+/-0.0008 g/ml, P = 0.632; Delta%BF = 0.1+/-1.3, P = 0.665), while for women, there were small but significant differences in Db and %BF between BP1 and BP2 (DeltaDb = 0.0018+/-0.0003 g/ml, P = 0.001; Delta%BF = 0.8+/-1.1, P = 0.001). The regression between %BF by BP1 and BP2 did not deviate significantly from the line of identity for both men and women (R2 = 0.95, standard error of estimate (s.e.e.) = 1.23 %BF for men; R2 = 0.97, s.e.e = 1.13 %BF for women). Individual variations in %BF estimates between the two BP units were within acceptable ranges (95% limits of agreement = -2.5-2.7 %BF for men; -1.4-3.0 %BF for women), and there was no trend in individual differences as %BF varied (r = -0.19, P = 0.359 for men; r = 0.09, P = 0.677 for women). Other subject characteristics, including age, body mass, height, and body mass index, did not significantly contribute to the differences in %BF estimates by the two BP units. No clinically significant differences in Db and %BF estimates exist between the BP units, and the interdevice variability of the BP has minimal impact on %BF estimates. Further, test-to-test reliability between BP units appears to be as good as within one unit.

Clinical outcomes measurement: Interrater & interdevice reliability of physical therapist & client rating of low back pain with a visual analogue scale & a picture scale

The purposes of this study were to assess congruence between 1) physical therapist and client perception of low back pain and 2) Visual Analogue Scale (VAS) and Picture Scale (PS) pain ratings. Congruence of practitioner and client pain rating is essential in clinical decision making. Clinical use of these scales is widespread. However, there is limited research regarding their reliability in rehabilitation medicine. The sample of convenience (n = 28) consisted of volunteer subjects (median age = 40.5 years), from one outpatient orthopedic physical therapy practice, that were experiencing low back pain. A physical therapist and client simultaneously rated the client’s pain with the VAS and PS. Each was blinded to the other’s rating. The VAS was standard (10 cm. line) and the PS consisted of eight (8) hierarchically arranged realistic facial expressions. Descriptive statistics were used to summarize demographic and pain rating data. The Spearman (rho) Rank Correlation was used to determine the relationship between therapist and client pain ratings, and between VAS and PS scores. The Wilcoxon Signed Rank (α2=.05) was used to determine if there were corresponding significant differences. There was high correlation between physical therapist and client using the VAS (rranks=.80) and the PS (rranks=.75), and between VAS and PS values for physical therapists (rranks=.93) and clients (rranks=.83. There was no statistically significant difference (p>.05) between physical therapist and client pain ratings using either scale. However, there was a statistically significant difference between client VAS and PS ratings. Interrater reliability of the VAS and PS is high, suggesting that physical therapists can rely upon their judgement of client pain using either of these scales, in clinical decision making. However, interdevice reliability of these scales is questionable suggesting that the scales are interpreted differently and should not be used interchangeably.

Reliability of range-of-motion measurement in the elbow and forearm

The purpose of this study was to examine intratester, interester, and interdevice reliability of range of motion measurements of the elbow and forearm. Elbow flexion and extension and forearm pronation and supination were measured on 38 subjects with elbow, forearm, or wrist disease by 5 testers. Standardized test methods and a randomized order of testing were used to test groups of patients with universal standard goniometers, a computerized goniometer, and a mechanical rotation measuring device. Intratester reliability was high for all 3 measuring devices. Meaningful changes in intratester range of motion measurements taken with a universal goniometer occur with 95% confidence if they are greater than 6° for flexion, 7° for extension, 8° for pronation, and 8° for supination. Intertester reliability was high for flexion and extension measurements with the computerized goniometer and moderate for flexion and extension measurements with the universal goniometer. Meaningful change in interobserver range of motion measurements was expected if the change was greater than 4° for flexion and 6° for extension with the computerized goniometer compared with 10° and 10°, respectively, if the universal goniometer was used. Intertester reliability was high for pronation and supination with all 3 devices. Meaningful change in forearm rotation is characterized by a minimum of 10° for pronation and 11° for supination with the universal goniometer. Reliable measurements of elbow and forearm arm movement are obtainable regardless of the level of experience when standardized methods are used. Measurement error was least for repeated measurements taken by the same tester with the same instrument and most when different instruments were used.

Comparison of Trunk Strength Measurements Between Two Different Isokinetic Devices Used at Clinical Settings

Intradevice reliability of isokinetic trunk strength measurements has been studied frequently, but no evidence is available on interdevice reliability. This motivated the present study, in which two isokinetic devices, the Ariel 5000 and Lido Multi-Joint II, were compared in a sample of 41 subjects (20 healthy and 21 low back pain subjects). The measurements were made in a random order with both machines. The results showed that the two isokinetic machines gave quite different results in trunk flexion-extension strength measurements. A statistically significant difference was present in the average peak torques between the two devices, with the exception of flexion at low angular velocity (60 degrees/s), and the correlations between the two measurements were low. The results were assumed to be more of a reflection of the interdevice variations (hardware and software, attachment of the subject) than of learning effects or other phenomena. We conclude that isokinetic trunk-muscle strength test results with the Ariel and Lido are device specific, and one cannot automatically compare results obtained from different devices with each other.

Comparison of Trunk Strength Measurements Between Two Different Isokinetic Devices Used at Clinical Settings

Intradevice reliability of isokinetic trunk strength measurements has been studied frequently, but no evidence is available on interdevice reliability. This motivated the present study, in which two isokinetic devices, the Ariel 5000 and Lido Multi-Joint II, were compared in a sample of 41 subjects (20 healthy and 21 low back pain subjects). The measurements were made in a random order with both machines. The results showed that the two isokinetic machines gave quite different results in trunk flexion-extension strength measurements. A statistically significant difference was present in the average peak torques between the two devices, with the exception of flexion at low angular velocity (60°/s), and the correlations between the two measurements were low. The results were assumed to be more of a reflection of the interdevice variations (hardware and software, attachment of the subject) than of learning effects or other phenomena. We conclude that isokinetic trunk-muscle strength test results with the Ariel and Lido are device specific, and one cannot automatically compare results obtained from different devices with each other.

Interdevice Reliability and Validity Assessment of the Nicholas Hand-Held Dynamometer

The Nicholas Hand-Held Dynamometer (HHD) has been shown to have excellent interday and intraday reliability when using the same HHD. Since clinics may have more than one HHD with which to evaluate patients, it would be of value to know if two identical HHDs measure the same variable consistently. The purpose of this investigation was to assess interdevice reliability of the Nicholas HHD as well as to determine its validity. Thirty healthy female subjects between the ages of 20 and 56 years (mean age = 28.4) were tested for hamstring strength. Three measurements of maximum hamstring contractions were obtained using the first HHD (Device A). The average of these three measurements was compared with the average of three measurements obtained after a brief rest using a second HHD (Device B). Measurements from the two HHDs were also compared with measurements obtained from a Kin-Com isokinetic dynamometer. The Kin-Com measurements were used as criteria to determine validity of the HHD. An intraclass correlation coefficient (ICC) calculated to determine reliability between the two HHDs was low (ICC = .58). Pearson product-moment correlation coefficients were calculated between the Kin-Com and each of the two HHDs. These values were .85 and .83 for Device A and B, respectively. Analysis of variance showed no significant difference between the Kin-Com and Device A but a significant difference between the Kin-Com and Device B (p < .001). Measurements obtained from two identical HHDs may be significantly different and should not be compared.

GONIOMETRIC RELIABILITY IN A CLINICAL SETTING. ELBOW AND KNEE MEASUREMENTS

Reliability of goniometric measurements has been examined only under standardized conditions and usually with healthy subjects. The purpose of this study was to assess goniometric reliability in a clinical setting. The reliability of goniometric measurements of passive elbow and knee positions was assessed using patients as subjects. The effect of using the means of repeated measurements and the interdevice reliability of three common goniometers were also examined. Results showed that intratester reliability for flexion and extension of the knee and the elbow joints was high (r = .91 to .99). Intertester reliability was also high (r = .88 to .97) for these measurements except for measurements of knee extension (r = .63 to .70). Although previous investigators have suggested that using the means of multiple measurements improves reliability, our data indicate that this procedure never improves the correlation coefficient more than .12. The reliability was similar for all three devices. The results of this study indicate that for the knee and elbow joints, goniometric measurements performed in a clinical setting can be highly reliable. The method described in this study provides a simple protocol that can be used clinically to investigate goniometric reliability.

Goniometric reliability in a clinical setting. Elbow and knee measurements.

Reliability of goniometric measurements has been examined only under standardized conditions and usually with healthy subjects. The purpose of this study was to assess goniometric reliability in a clinical setting. The reliability of goniometric measurements of passive elbow and knee positions was assessed using patients as subjects. The effect of using the means of repeated measurements and the interdevice reliability of three common goniometers were also examined. Results showed that intratester reliability for flexion and extension of the knee and the elbow joints was high (r = .91 to .99). Intertester reliability was also high (r = .88 to .97) for these measurements except for measurements of knee extension (r = .63 to .70). Although previous investigators have suggested that using the means of multiple measurements improves reliability, our data indicate that this procedure never improves the correlation coefficient more than .12. The reliability was similar for all three devices. The results of this study indicate that for the knee and elbow joints, goniometric measurements performed in a clinical setting can be highly reliable. The method described in this study provides a simple protocol that can be used clinically to investigate goniometric reliability.