Difficulty or dependency? Effects of measurement scales on disability prevalence among older Americans.

This study examines how the prevalence of disability among subgroups of older persons is influenced by the activity of daily living (ADL) scale selected. Using the 1993 Survey of Asset and Income Dynamics of the Oldest Old, we construct four disability scales, ranging from difficulty performing an ADL to receiving help with an ADL, or dependency. In all instances, the difficulty scales produce substantially higher estimates of disability than the dependency scales. Larger percentages of women, Blacks, and less educated persons are classified disabled under all scales compared with men, Whites, and more educated persons. Specific subgroups are more sensitive to the scale used. The policy implications of using ADL scales to establish program eligibility are discussed.