FUNCTIONAL STATUS INDEX - RELIABILITY OF A CHRONIC DISEASE EVALUATION INSTRUMENT

  • 1 January 1980
    • journal article
    • research article
    • Vol. 61  (9) , 395-401
Abstract
The reliability of 3 methods of assessing respondents'' perceptions of their functional ability was tested. The Functional Status Index defines function as including 3 distinct but related dimensions: the degree of dependence, the degree of difficulty and the amount of pain experienced in performing specific activities of daily living. Adults [149] with rheumatoid arthritis were studied. Exploratory factor analysis of scores on 18 specific daily activities across the 3 hypothesized dimensions yielded the following functional categories: gross mobility, hand activities, personal care, home chores and interpersonal activities. These indices achieve internal consistency reliability levels ranging from 0.66-0.91 across all but 1 functional category. Average test-retest and interobserver reliability values range from 0.65-0.81. Levels of interobserver reliability generally equal or surpass levels of test-retest reliability. It is feasible to quantify level of function using self-report methods. The Functional Status Index is recommended for use in investigations where changes in functional ability are of interest.