Implications of asking "ambiguous" difficulty questions: an analysis of the second wave of the asset and health dynamics of the oldest old study.

OBJECTIVES: This study explores the analytic implications of using questions about difficulty with daily activities that do not specify whether to consider assistance.
METHODS: For 1,054 Asset and Health Dynamics of the Oldest Old Study Wave 2 respondents, we compared responses to questions about difficulty without reference to assistance (ambiguous difficulty) to those about difficulty without help or equipment (underlying difficulty) and difficulty with help or equipment, if used (residual difficulty). We modelled predictors of discordance by means of logistic regression.
RESULTS: Discordance exists for 15% of respondents between summary variables indicating underlying and ambiguous difficulty with one or more activities. Discrepancies are evenly split between respondents reporting (a) underlying but no ambiguous difficulty and (b) ambiguous but no underlying difficulty. Discordance also exists for 15% of respondents between summary variables indicating residual and ambiguous difficulty with one or more activities: most of these discrepancies involve reports of ambiguous but no residual difficulty. Most respondent characteristics investigated are not significant predictors of discrepancies. DISCUSSION: Analysts should be aware that (a) ambiguously worded questions appear to be a better proxy for underlying than for residual difficulty, (b) discrepancies seem to be lower for separate activities than for summary variables indicating difficulty with one or more activities, and (c) being Hispanic and receiving help may affect reporting discrepancies.