THE ARM MOTOR ABILITY TEST - RELIABILITY, VALIDITY, AND SENSITIVITY TO CHANGE OF AN INSTRUMENT FOR ASSESSING DISABILITIES IN ACTIVITIES OF DAILY LIVING

Objective: To continue and expand determination of the reliability, va lidity, and sensitivity to change of the Arm Motor Ability Test (AMAT) , an instrument for assessing deficits in activities of daily living ( ADL). Design: The AMAT was administered twice to patients, with an int erest interval of either 1 or 2 weeks, by one of two examiners assigne d to patients in counterbalanced order. Patients' interest intervals a nd scores on the arm portion of the Motricity Index was unknown to the raters. Setting: A referral inpatient neurological rehabilitation cen ter. Patients: Thirty-three subacute stroke inpatients with moderate t o mild upper extremity motor deficit: median Motricity-Index-Arm score = 89, median chronicity = 43d, median age = 66yr; 12 were women. Main Outcome Measure and Results: The AMAT was developed in 1987, and inte rrater reliabilities at that time were found to range from .95 to .99. The present values for interrater reliability (2 scales) from videota ped test performance were: kappas = .68 to .77, Spearman correlations = .97 to .99. For performance time, interscorer reliability from video taped test performance was .99. Homogeneities for the three AMAT measu res for the total sample (Cronbach's alpha and split-half reliability) were .93 to .99. The test-retest reliabilities for the total sample w ere .93 to .99. The correlations to the Motricity-Index-Arm score were .45 to .61. The AMAT detected the difference in change occurring as a result of the passage of 1 versus 2 weeks in these subacute inpatient s, presumably as a result of intensive therapy and/or spontaneous reco very, confirming the results of an earlier intervention study. Conclus ion: The AMAT is an instrument with high interrater reliability, inter nal consistency, and sensitivity to change, as well as having satisfac tory concurrent validity. (C) 1997 by the American Congress of Rehabil itation Medicine and the American Academy of Physical Medicine and Reh abilitation.