Nursing home assessment of cognitive impairment: development and testing of a brief instrument of mental status.

OBJECTIVES

To test the accuracy of a brief cognitive assessment of nursing home (NH) residents and to determine whether facility nurses can reliably perform this assessment.

DESIGN

Cross-sectional, independent cognitive screening tests with NH residents.

SETTING

Six Department of Veteran Affairs nursing facilities.

PARTICIPANTS

Three hundred seventy-four residents from six regionally distributed Veteran Affairs NHs.

MEASUREMENTS

Three cognitive assessment instruments: the Brief Interview of Mental Status (BIMS), created for this study; the Minimum Data Set (MDS) 2.0 Cognitive Performance Scale (CPS), and the Modified Mini-Mental State Examination (3MS) as the criterion standard. The 15-point BIMS tests memory and orientation and includes free and cued recall items. Research assistants administered the 3MS and BIMS to all subjects. Facility nurses administered the same BIMS to a subsample.

RESULTS

Three hundred seventy-four of 417 (89.7%) residents approached completed the 3MS and research assistant-administered BIMS (BIMS-R); 212 residents also received a facility nurse-administered BIMS (BIMS-N). The BIMS-R was more highly correlated with the 3MS than was the CPS (Pearson correlation coefficient (r)=0.79 vs 0.62; P<.01 for difference). For the subset who received facility assessments, the BIMS-N was also more highly correlated with the 3MS (Pearson r=0.74 vs 0.65; P<.01 for difference). For any impairment (3MS<78), the area under the receiver operator characteristic curve (AUC) was 0.86 for the BIMS, versus 0.77 for the CPS. For severe impairment (3MS<48) the AUC was 0.94, versus 0.85 for the CPS.

CONCLUSION

In this population, a brief cognitive test is a more accurate approach to cognitive assessment than the current observational methods employed using the MDS 2.0.