Purpose: The aim of this study was to validate a pain scale for the Minimum
Data Set (MDS) assessment instrument and examine prevalence of pain in maj
or nursing home subpopulations, including type of admission and cognitive s
tatus. Design and Methods: This study considered validation of the MDS pain
items and derivation of scale performed against the Visual Analogue Scale
(VAS), using Automatic Interaction Detection. The derivation data describe
95 postacute care nursing home patients who are able to communicate. The sc
ale is then used in retrospective analysis of 34,675 Michigan nursing home
residents. Results: A four-group scale was highly predictive of VAS pain sc
ores (variance explanation 56%) and therefore quite valid in detecting pain
. In the prevalence sample, only 47% of postacute patients compared to 63%
of postadmission patients reported no pain, and these percentages rose with
increasing cognitive impairment. Implications: Pain is prevalent in nursin
g home residents, especially in those with cognitive dysfunction, and often
untreated.