BIMS Scoring · Brief Interview for Mental Status (0-15) Cut-offs

The BIMS (Brief Interview for Mental Status) is the structured cognitive interview in Section C of the Minimum Data Set (MDS) 3.0, the assessment US nursing homes complete for residents. Staff ask a few questions on word registration, orientation to time and delayed recall, and add the codes into a summary score from 0 to 15 ^{[1] [2]}.

What does the BIMS measure?

The BIMS screens for cognitive impairment through direct performance rather than staff observation. It covers three areas ^[2]:

• Registration. Whether the resident can repeat three words straight after hearing them.
• Temporal orientation. Whether the resident can name the current year, month and day of the week.
• Delayed recall. Whether the resident can recall the three words a few minutes later, with or without a category cue.

It was designed for MDS 3.0 to replace observation-only coding of cognition, which could mislabel residents based on appearance or an assumed diagnosis ^{[1] [2]}. CMS also uses the interview as a chance to observe residents for signs of delirium and to compare performance across assessments ^[2].

The BIMS is one of several brief cognitive screens. For a fuller office-based screen, see the MoCA, MMSE or SLUMS; for a three-minute screen outside the MDS, see the Mini-Cog.

Terms of use

The BIMS is part of MDS 3.0, published by the Centers for Medicare & Medicaid Services. The RAI manual's legal notice reads: "Copyright 2011 United States of America and interRAI. This work may be freely used and distributed solely within the United States." ^[2]. This page describes the items by task and does not reproduce their wording; use the current manual from CMS ^[3].

How do you give the BIMS?

• Who gives it. Nursing home staff completing the MDS assessment. If the interviewer cannot pronounce the items clearly, for example because of an accent or speech impairment, a different staff member should conduct it ^[2].
• Who is interviewed. CMS asks staff to attempt the interview with all residents, using their preferred language and an interpreter if needed. It is skipped only when the resident is rarely or never understood, cannot respond in any form, or a needed interpreter is not available ^[2].
• Setting. One sitting, in a private place if possible, with background noise minimized, the resident's usual hearing aids or devices in use, and the interviewer's face visible ^[2].
• Order. Ask the items in the order given, without adding up the score during the interview ^[2].
• Written format. When a resident's primary method of communication is writing, the BIMS can be given in writing; CMS limits written administration to that circumstance ^[2].
• Stopping early. CMS sets rules for stopping after the orientation items when every answer so far has been nonsensical or absent ^[2].
• Time. An average of 3.2 minutes in the national validation study ^[1].

How do you score and interpret the BIMS?

Each item is coded, then the codes are added for the summary score (item C0500) ^[2]:

CMS gives this guidance for a carefully conducted interview in which the resident can hear every question and is not delirious ^[2]:

Incomplete interviews. A refused item is coded as incorrect and still counts. If the resident declines the interview, or gives no answer or a nonsensical answer to four or more items, the summary is coded 99 (unable to complete) and staff complete the Staff Assessment for Mental Status. A total of 0 is a legitimate score, not an incomplete interview ^[2].

Reading the score. CMS describes the BIMS as a brief screener that does not assess every aspect of cognition. A diagnosis of dementia should follow a careful assessment for other causes, and the final judgement on the level of impairment rests with the resident's physician or mental health specialist ^[2]. An abrupt drop between assessments may signal delirium and a possibly serious medical illness ^[2].

Psychometric properties

All figures below come from the national MDS 3.0 evaluation in 71 community nursing homes across eight US states ^[1].

• Feasibility. The BIMS was attempted and completed with 90% of 3,258 residents, and scores covered the full 0-15 range.
• Criterion validity. In a validation sample of 418 residents, the BIMS correlated 0.906 with the Modified Mini-Mental State Examination (3MS), higher than the observation-based MDS 2.0 Cognitive Performance Scale (-0.739).
• Any impairment. With a score of 12 as the cut-off, sensitivity was 0.83 and specificity 0.91 (3MS below 78 as the reference); area under the curve 0.930.
• Severe impairment. With a score of 7 as the cut-off, sensitivity was 0.83 and specificity 0.92 (3MS below 48 as the reference); area under the curve 0.960.
• Staff view. 88% of surveyed staff reported that the BIMS gave new insight into residents' cognitive abilities.

Limitations

• Screening, not diagnosis. CMS describes it as a brief screener; it does not diagnose dementia or identify its cause ^[2].
• Narrow coverage. It tests registration, orientation to time and recall only. It does not assess executive function, language or visuospatial skills, which screens such as the MoCA or a clock drawing test cover.
• Hearing and delirium. The CMS bands assume the resident heard every question and was not delirious ^[2]. Hearing loss, frailty or lack of interaction can make a cognitively intact resident appear impaired ^[2].
• Built for one setting. It was developed and validated in US nursing home residents as part of the MDS ^[1].
• Other questions. Informant measures such as the IQCODE, and staging scales such as FAST or the Global Deterioration Scale, answer different questions.
• Mood. CMS notes a decline in mental status may be associated with a mood disorder ^[2]; in older adults, a depression screen such as the GDS can help separate the two.