Christine C. Chen

Test-Retest Reproducibility and Smallest Real Difference of 5 Hand Function Tests in Patients With Stroke

Objective. To investigate the test-retest reproducibility and smallest real difference (SRD) of 3 hand strength tests (grip, palmar pinch, and lateral pinch) and 2 dexterity tests (the Box and Block test [BBT] and the Nine Hole Peg test [NHPT]) in patients with stroke. Methods. The 5 tests were administered on 62 stroke patients in 2 sessions, 3 to 7 days apart. The intraclass correlation coefficient (ICC) was used to determine the level of reproducibility between measurements on 2 sessions. The SRD was used to determine the extent of measurement error because of chance variation in individual patients. SRD percentage (SRD relative to mean score) was used to compare test-retest reliability across tests. We analyzed the group as a whole, then in 2 subgroups (hand spasticity vs none). Results. The test-retest reproducibility of all 5 tests was high for all the patients, with ICCs ranging from 0.85 to 0.98. The SRDs for the more/less affected hand were: 2.9/4.7 kg for the grip test; 1.2/1.3 kg for the palmar pinch test; 1.4/1.0 kg for the lateral pinch test; 5.5/7.8 blocks/minute for the BBT; and 32.8/6.2 seconds for the NHPT. Unacceptably high SRD percentages (>30%) were found for the affected hand using the NHPT (54%), palmar pinch (35%), and lateral pinch (34%). When comparing these indices for participants with spasticity versus none for all 5 tests, the ICCs were lower and the SRD and SRD percentage were higher for the spasticity group. Conclusions. All 5 tests demonstrated satisfactory test-retest reproducibility for a diverse group of patients with stroke. However, all tests showed higher levels of measurement error when performed with the more affected hand and in patients with hypertonicity of that hand. Thus, baseline and postrehabilitation change scores using these common tests of strength and dexterity must be interpreted with some caution, especially in poorly controlled clinical trials. Repeated measures ought to be incorporated to examine reliability within a trial that includes participants with a hypertonic hand.

Psychometric Validation of the Manual Ability Measure-36 (MAM-36) in Patients With Neurologic and Musculoskeletal Disorders

OBJECTIVES To evaluate the psychometric properties of the Manual Ability Measure-36 (MAM-36), a new hand function outcome measure, and to examine differences in manual abilities and item parameters in patients with neurologic and musculoskeletal conditions. DESIGN Convenience sample from 2 time periods, cross-sectional. SETTING Outpatient rehabilitation units and private hand clinics. PARTICIPANTS Patients (N=337; mean age, 50.3+/-14.9y) with a variety of neurologic and musculoskeletal (orthopedic) diagnoses. Most of these individuals were community dwelling, and all had residual functional limitations in the hand(s). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Rasch analysis was performed on MAM-36 data to evaluate both scale structure and psychometric properties, which include rating distribution, step measures, item fit, separation, and dimensionality. A t test was performed to examine the differences in manual abilities in patients with the 2 conditions. Uniform differential item functioning (DIF) between neurologic and musculoskeletal groups was examined. (DIF occurs when subgroup members within the sample with the same level of the underlying trait being measured respond differently to an individual item.) Manual ability estimates were recalibrated with step and common item anchoring; they were compared with those derived from the original analysis. RESULTS The 36 items measured a single construct with no misfitting items. The scale was used as intended. The items can reliably separate the participants into 5 ability strata. Neurologic patients had a significantly lower mean manual ability than musculoskeletal patients. Fourteen items exhibited DIF. However, DIF had no effect on either scale quality or calibration of manual ability. We decided that a single rating scale is appropriate for both groups. CONCLUSIONS This study showed that the MAM-36 has more than adequate psychometric properties and can be used as a generic outcome measure for patients with a wide variety of clinical diagnoses.

Grip strength, perceived ability, and health status in individuals with arthritis: an exploratory study.

The purpose of this study is twofold: (1) to describe the hand strength, self-reported manual ability and health status in individuals with osteo- or rheumatoid arthritis, and (2) to evaluate the scale (psychometric) properties of the 36-item Manual Ability Measure (MAM) as it applied to this sample. We administered four self-report assessments to the participants and measured their grip and pinch strength. The results indicated that persons with arthritis had decreased grip and pinch strength, more functional limitations, compromised health status and restricted participation in everyday occupations when compared to the general population. Manual ability was not related to grip strength, but was significantly related to role restriction (i. e., SF-36 Role Physical domain). The study provides evidence that the MAM has adequate psychometric properties when used with patients with osteo- or rheumatoid arthritis.

Responsiveness of the Manual Ability Measure—36 (MAM–36): Changes in Hand Function Using Self-Reported and Clinician-Rated Assessments

OBJECTIVE. To examine the responsiveness of the Manual Ability Measure-36 (MAM-36) compared with a clinician-administered functional assessment. METHOD. The MAM-36 was administered to 46 patients (Cohort A, n = 20; Cohort B, n = 26) with various upper-extremity conditions. All patients received occupational therapy intervention for 2-37 wk and were retested at discharge. Additionally, the Smith Hand Function Test (SHFT), including task performance speeds and grip strength measurements, was administered to Cohort B at intake and discharge. RESULTS. Manual ability improved significantly at discharge in all patients. Patients also showed significant improvement on the SHFT. The correlation between gain in MAM-36 and gain in grip strength was moderate. The standardized response mean for the MAM-36 was 1.18. CONCLUSION. The MAM-36 was responsive to changes in hand function in patients receiving occupational therapy services. MAM-36 results correlated positively with improvements in task performance speeds and grip strength.

Smallest Real Difference of 2 Instrumental Activities of Daily Living Measures in Patients With Chronic Stroke

OBJECTIVE To estimate the smallest real difference (SRD) values of 2 instrumental activities of daily living measures (the Nottingham Extended Activities of Daily Living [NEADL] and the Frenchay Activities Index [FAI]) in patients with chronic stroke. DESIGN Test-retest reliability study. SETTING Physical rehabilitation units of 5 hospitals. PARTICIPANTS Chronic stroke patients (N=52; 37 men, 15 women) who were discharged from the hospital for more than 6 months. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Both measures were administered twice about 2 weeks apart to participants. The SRD was calculated on the basis of standard error of measurement: SRD = 1.96 × √2 × Standard error of measurement. SRD% (the value of SRD divided by total score of a measure) was used to compare measurement errors across both measures. Reproducibility between successive measurements of the measures was investigated with intraclass correlation coefficients (ICCs). RESULTS The SRD (SRD%) values of the NEADL and the FAI were 12.0 (21.1%) and 6.7 (14.9%), respectively. Test-retest reproducibility of both measures was high (ICC: NEADL=.89, FAI=.89). CONCLUSIONS Because of substantial SRD values of the NEADL and the FAI, prospective users should be cautious in using both measures to detect real change for a single subject.

The development and preliminary validation of the Taiwanese Manual Ability Measure for Burns

OBJECTIVE To develop and validate the Taiwanese Manual Ability Measure for Burns (T-MAM for Burns), a task-oriented functional evaluation tool to assess self-reported manual ability in burn patients. DESIGN A longitudinal study. PARTICIPANTS A sample of 45 burn patients from burn rehabilitation centers with varying degrees of hand involvement. METHODS The preliminary testing version was formed by adding burn specific items to the Taiwanese version of the Manual Ability Measure. A field test was then conducted for item reduction and psychometric properties testing. RESULTS Out of 55 initial items, 20 were selected into the final version of the T-MAM for Burns. Psychometric analyses indicated that it was reliable (test-retest ICC=.99), with adequate concurrent validity with various other hand function tests (r=-.79 with the short form Disabilities of the Arm, Shoulder, and Hand, or, the QuickDASH) and discriminative validity (significant difference (t=2.99, P=.005) between groups with unilateral vs. bilateral hand burns), and responsive (ES=.24 and .44 at one- and 3-month evaluations). CONCLUSION This study shows that the T-MAM for Burns has great potential to be a functional outcome measure for burn rehabilitation. Additional research with a larger sample should be conducted to further confirm its validity and reliability.

Coherent Perfect Absorption in a Silicon Ring Resonator

We present the first experimental demonstration of coherent perfect absorption (CPA) in an integrated device. By leveraging the effects of CPA, phase-controlled modulation is achieved in a silicon photonic ring-resonator with an extinction of 8.12dB.