Free, two-minute dementia screen compares well to longer mini-assessments

A new, 16-question mental status exam provides quicker cognitive impairment screening in a primary care or hospital setting, according to researchers who developed the test.

The researchers developed the "Sweet 16" exam, which comprises 16 scored items worth one point each and takes about two minutes to complete. The exam includes eight items that assess orientation in time and space; three registration items involving immediate repetition; two practice and two scored digit span items (practice items count forward, scored items count backward); and three recall items. The items were chosen based on widely used cognitive assessment measures that test areas most likely to be impaired, such as memory. The exam doesn't require pen and paper to complete and can be administered by clinical or lay staff in different settings, according to an article in the Nov. 8 Archives of Internal Medicine.

Current screening tests take about 15 minutes, require the patient to write or copy patterns with pen and paper, or may be affected by poor vision or lower educational levels. Also, the Mini-Mental State Exam is copyrighted, requiring fees to use.

In the development cohort, the Sweet 16 highly correlated with the MMSE (Spearman r, 0.94; P<0.001). The overall agreement between the Sweet 16 and the MMSE at clinically relevant thresholds (<14 for Sweet 16 and <24 for MMSE) was a weighted κ of 0.60 (P<0.001). Equipercentile equating, defined as "a procedure that creates the same percentile distributions across both scales," identified Sweet 16 cut points that correlated with MMSE cut points, as follows:

MMSE (Sweet 16)

• 24 (13.1)
• 20 (10.9)
• 18 (9.7)
• 10 (4.6)

An MMSE score of 24 is widely used to indicate cognitive impairment. Because the equivalent value on the Sweet 16 falls between integers, researchers opted for a Sweet 16 value less than 14 as the cutoff for cognitive impairment, as it maximizes sensitivity compared to the MMSE (80% vs. 70%). The Sweet 16 is also more able to exclude disease. The likelihood ratio for a negative test result was 0.29 for the Sweet 16 compared with 0.42 for the MMSE. And across a range of education levels, the area under the curve for higher education (>12 years) was 0.90 for the Sweet 16 and 0.84 for the MMSE (P=0.03).

The Sweet 16 is a screening exam that requires follow-up with a more comprehensive exam, researchers noted. "[T]he Sweet 16 may be preferred over the MMSE in frail older or medically ill hospitalized or institutionalized patients in whom the ability to write and manipulate props may be limited for reasons other than cognitive impairment (eg, intravenous tubing, positioning in bed) and in situations such as a busy clinical practice or a large study cohort in which the ability to quickly complete a cognitive assessment is essential," they wrote.

The Sweet 16 tool is available online.