Rasch analysis of Minimum Data Set mandated in skilled nursing facilities.

This study examined the construct validity of the physical functioning and cognition scales of the federally mandated Minimum Data Set (MDS) via Rasch analysis. We performed a secondary analysis of retrospective MDS data collected by the Department of Veteran Affairs Austin Automation Center. Items demonstrated unidimensionality and represented two separate constructs: physical functioning and cognition. The physical functioning items showed good psychometric properties and covered a wide range of residents' physical functioning, with the spread of items efficiently discriminating residents' performance into different physical functioning strata. In contrast, the psychometric properties of the cognition items were less sound, had severe ceiling effects, and did not efficiently discriminate residents' performance into different cognition strata. The constructed validity of the physical functioning and cognition scales of the MDS, in general, was supported. Future investigations into the function of the rating scale and the necessity of adding challenging items are recommended.