Rasch analysis of the Milwaukee Evaluation of Daily Living Skills

Carol Ann Leonardelli Haertlein, Marquette University


The functional status of individuals receiving health care services is of increasing interest in the changing health care industry of the 1990s. Accurate assessment of impaired, disabled, and handicapped individuals is critical to determine their functional abilities and deficits. The Milwaukee Evaluation of Daily Living Skills (MEDLS) was developed in the mid-1980s to provide a behavioral measure of the abilities of persons with long-term mental illness to do basic and complex activities of daily living. Classical methods of test development were used to develop the instrument as it was published in 1988. Since that time, techniques of modern test theory, specifically Rasch analysis, have been increasingly used in the development of functional assessments in rehabilitation. The purpose of the project described here was to apply Rasch analysis to a revised version of the MEDLS in order to examine its validity and reliability. The MEDLS was administered to 100 persons with a long-term mental illness. Three raters were used to collect data. The scores for all items on the two scales of the MEDLS (performance and knowledge/judgement) were evaluated using the many-faceted Rasch analysis computer program FACETS. The scales were found to have construct validity, a logical hierarchical ordering of items by difficulty (confirmed by p-values), person-response validity, and consistency among raters on the performance scale. The MEDLS was found to not have enough difficult items for the target population, to have fairly large standard errors on items especially more difficult ones, to have some inconsistency among raters on the knowledge/judgement scale, and to be unable to differentiate among subgroups of the target population. The many-faceted Rasch model of analysis is able to provide comprehensive and detailed reliability and validity data which is more explicit than traditional procedures. Suggestions for revisions of the MEDLS and future research are included.

Recommended Citation

Haertlein, Carol Ann Leonardelli, "Rasch analysis of the Milwaukee Evaluation of Daily Living Skills" (1993). Dissertations (1962 - 2010) Access via Proquest Digital Dissertations. AAI9411517.