Abstract
This article examines how respondents understood items in the Spanish versions of the Short-Form 36 (SF-36v2). Cognitive interviews of the SF-36 were conducted in 2 phases with 46 Spanish speakers living in the United States. Roughly one-third (17/46) of respondents had difficulty understanding the Role Emotional items upon their initial reading, and almost half (21/46) provided examples that were inconsistent with the intended meaning of the items. The findings of this study underscore the importance of conducting cognitive testing to ensure conceptual equivalence of any instrument regardless of how well validated it appears to be.