Clinical Dementia Rating (CDR): Global and Sum of Boxes

What it measures

The Clinical Dementia Rating is a clinician-rated staging instrument. You score six domains, or "boxes": Memory, Orientation, Judgment & Problem Solving, Community Affairs, Home & Hobbies, and Personal Care. Each box is rated 0 (none), 0.5 (questionable), 1 (mild), 2 (moderate) or 3 (severe). Personal Care has no 0.5 rating. Each level in the tool shows its standard anchor description.

Score only decline from the person's own previous usual level that is due to cognitive loss, not impairment from other causes such as physical disability or depression. Score each domain on its own, and when a rating is unclear, choose the box of greater impairment.

Scoring

The tool calculates two results. The global CDR (0, 0.5, 1, 2 or 3) comes from the Morris (1993) scoring rules, with Memory as the primary category and the other five domains as secondary. The CDR Sum of Boxes (CDR-SB) is the sum of all six box scores (0-18), staged as follows:

CDR-SB	Stage
0	Normal
0.5-4.0	Questionable / very mild
4.5-9.0	Mild dementia
9.5-15.5	Moderate dementia
16.0-18.0	Severe dementia

Interpreting the result

Each global CDR level comes with a short clinical interpretation. These run from normal cognition (CDR 0), through very mild or questionable impairment that may represent mild cognitive impairment (CDR 0.5), to mild, moderate and severe dementia (CDR 1, 2 and 3). The interpretations also include notes on workup, treatment and care planning for each stage.

What the report includes

The summary gives the date, the global CDR and its stage, the CDR-SB and its stage, a table of the six box scores with their impairment levels, the clinical interpretation, the CDR-SB staging key, and the Morris (1993) citation. You can copy it as plain text or print it to PDF. The tool will not calculate until all six domains are scored.