Anderson R A, Su H F, Hsieh P C, Allred C A, Owensby S, Joiner-Rogers G
Duke University School of Nursing, DUMC 3322, Durham, NC 27710, USA.
Res Nurs Health. 1999 Aug;22(4):271-83. doi: 10.1002/(sici)1098-240x(199908)22:4<271::aid-nur2>3.0.co;2-6.
Case mix indicates, for a resident population, the degree of risk for developing favorable or unfavorable outcomes. In a study of 164 nursing homes, we explored two methods for combining resident assessment data into a case mix index (CMI). We compared a facility-level, composite CMI to a prevalence-based CMI comprised of 22 separate resident characteristics for their adequacy in explaining resident outcomes. The prevalence-based CMI consistently explained more variance in outcomes than the facility level, composite CMI. This study indicates a reasonable method for using administrative databases containing resident assessment data to adjust for the influence of case mix on nursing home resident outcomes.