HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Manini, T. M. Articles by Ploutz-Snyder, L. PubMed PubMed Citation Articles by Manini, T. M. Articles by Ploutz-Snyder, L.

Evaluating Task Modification as an Objective Measure of Functional Limitation: Repeatability and Comparability

¹ Department of Exercise Science, Syracuse University, New York.
Departments of ² Physical Therapy and ³ Physical Medicine Rehabilitation, SUNY Upstate Medical University, Syracuse, New York.

Address correspondence to Todd Manini, PhD, Laboratory of Epidemiology, Demography and Biometry, National Institute on Aging, Gateway Bldg., Suite 3C-309, 7201 Wisconsin Ave., Bethesda, MD 20892-9205. E-mail: maninit{at}mail.nih.gov

Background. Modification of everyday tasks in older adults is associated with risk of deleterious health outcomes. The purpose of this study was to develop a task modification scale to examine its reliability and comparability to timed performance and common measures of physical function and impairment.

Methods. Eighty-two (21 men, 61 women) older adults (74.4 ± 8.2 years) were observed performing a chair rise (sitting heights: 43 cm, 38 cm, and 30 cm), stair ascent/descent, and kneel and supine rise tasks. Six hierarchically ranked categories (0–5) of modification were created for each task and then summed across tasks (summary modification [MOD] score: range 0–35). Comparisons were made with timed performance, knee extension strength, single-leg balance, self-reported function, five chair stands, and gait speed.

Results. Inter-rater reliability (intra-class correlation = 0.98) and participant repeatability (intra-class correlation = 0.92) of the MOD score were excellent. Ninety-six percent of participants modified at least one task (MOD score: 10.5 ± 7.51, range 0–27). After adjusting for task modification, timed performance showed a lower association with gait speed (time vs MOD score, semipartial r² = 0.31 vs 0.68), strength (semipartial r² = 0.14 vs 0.65), and single-leg balance (semipartial r² = 0.10 vs 0.40) than did the MOD score. The MOD score showed higher correlations with muscle strength and balance impairment than did other measures of functional limitation such as gait speed, time to complete five chair stands, and self-reported physical function.

Conclusion. Documentation of task modification is reliable across raters and repeatable within participants; in addition, it compares well with other measures of physical function and impairment. Task modification reveals important and intuitive information regarding physical limitation, and deserves greater attention.